Academic literature on the topic 'Broilers (Chickens)'
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Journal articles on the topic "Broilers (Chickens)"
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Feng, Ze-Qing, Ting Lian, Yong Huang, Qing Zhu, and Yi-Ping Liu. "Expression Pattern of Genes of RLR-Mediated Antiviral Pathway in Different-Breed Chicken Response to Marek’s Disease Virus Infection." BioMed Research International 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/419256.
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It has been known that the chicken’s resistance to disease was affected by chicken’s genetic background. And RLR-mediated antiviral pathway plays an important role in detection of viral RNA. However, little is known about the interaction of genetic background with RLR-mediated antiviral pathway in chicken against MDV infection. In this study, we adopted economic line-AA broilers and native Erlang mountainous chickens for being infected with MDV. Upon infection with MDV, the expression ofMDA-5was upregulated in two-breed chickens at 4, 7, and 21 d.p.i. It is indicated that MDA-5 might be involved in detecting MDV in chicken. Interestingly, the expression ofIRF-3andIFN-βgenes was decreased in spleen and thymus of broilers at 21 d.p.i, but it was upregulated in immune tissues of Erlang mountainous chickens. And the genome load of MDV in spleen of broiler is significantly higher than that in Erlang mountainous chickens. Meanwhile, we observed that the death of broiler mainly also occurred in this phase. Collectively, these present results demonstrated that the expression patters ofIRF-3andIFN-βgenes in chicken against MDV infection might be affected by the genetic background which sequently influence the resistance of chicken response to MDV.
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Flannery, A. V., J. S. Easterby, and R. J. Beynon. "Turnover of glycogen phosphorylase in the pectoralis muscle of broiler and layer chickens." Biochemical Journal 286, no. 3 (1992): 915–22. http://dx.doi.org/10.1042/bj2860915.
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Glycogen phosphorylase is a major sarcoplasmic protein in chicken pectoralis muscle, constituting approx. 4% of the total protein complement. In slow-growing layer chicks phosphorylase accumulated in parallel with muscle accretion, but in fast-growing broiler chicks the concentration of phosphorylase in the muscle increased (from 5 to 8 mg/g wet wt.) with time. In a 5-week period, the total amount of phosphorylase in the pectoralis muscles increased 18-fold in broiler chicks (from approx. 75 to 1400 mg total), but only 3-fold (from approx. 100 to 270 mg total) in layers. Pyridoxal phosphate, the cofactor of the enzyme glycogen phosphorylase, was used as a specific label to measure the rate of degradation of the enzyme in the pectoralis muscle of growing broiler and layer chickens in vivo. In young animals, the fractional rate of phosphorylase synthesis was similar in broiler and layer chickens (approx. 15%/day), but the rate of degradation in layers (5%/day) was 5-fold higher than in broilers (1%/day). As the animals aged, the rate of synthesis decreased, but more so in layers than in broilers. The rate of degradation of phosphorylase also decreased in layers, but in broilers it remained at the low level seen in young animals. The dramatically higher rate of phosphorylase accretion in the pectoralis muscles of the broilers is therefore achieved by an initial lower rate of degradation combined with a sustained difference between rates of synthesis and degradation.
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Romanovych, L. V., B. M. Kurtyak, M. S. Romanovych, O. I. Vishchur, and D. I. Mudrak. "Influence of vitamins E and C on the indices of pseudoeozinofiles fagocytosis in chickens broilers blood of cross ROSS-308." Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 20, no. 92 (2018): 169–71. http://dx.doi.org/10.32718/10.32718/nvlvet9235.
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The purpose of the research was to clarify the effect of chicken broilers feeding in the composition of mixed fodder with Vitamins E and C on the cellular link of non-specific resistance of the organism and, in particular, the parameters of pseudoiesinophils phagocytosis in blood. The research was carried out on chickens broiler – 308 grown in the farm “Fedyuk M” in the Zolochiv district of Lviv region. The keeping of the chickens was cellular with free access to feed and water. Experiments were conducted in 4 groups of broiler chickens of 100 chicks in each according to the scheme: the control group was fed with the standard feed (SC) according to the existing norms recommended for the cross ROSS-308; the first experimental group in addition to the SC received vitamin Е 1g/10 kg of mixed fodder; the second experimental group received vitamin C 2.5 g/10 kg of mixed fodder; the third experimental groups in addition to the ration received Vitamin C 2.5 g/10 kg and Vitamin E 1 g/10 of mixed fodder. For carrying out of immunological researches in chickens blood was taken in different age periods: 27-, 34- and 41-day-old age. In the whole blood, the phagocytic activity of pseudoiesinophils (FA), phagocytic index (FI) and phagocytic number (FF) were determined. For research, the daily culture of Escherichia coli (strain VKM-125) was used. The stimulatory effect of vitamins E and C in the composition of mixed fodder for chicken broiler broilers on the indices of pseudoiesinophils phagocytosis of blood was determined. As evidenced by a significantly higher phagocytic activity, phagocytic index and phagocytic count of pseudoiselinophils in blood of chickens in the experimental groups by comparison with the control group. At the same time there was a direct correlation between phagocytic activity and phagocytic index and index in blood of chickens broiler in experimental groups. At the same time, the ability of blood pseudoiesinophils to phagocytosis of microbial cells was higher in chicken broilers, which were fed with vitamin E and C.
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Kamaludin, Kamaludin, P. W. Dzikrillah, M. F. Azhoheru, et al. "Manajemen usaha Ayam Pedaging Jantan dan Betina dengan Penambahan Suplemen Organik Cair." PETERPAN (Jurnal Peternakan Terapan) 1 (December 26, 2019): 21–25. http://dx.doi.org/10.25181/peterpan.v1i1.1476.
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This study aims to determine the growth of broiler chickens and analyze the feasibility of broiler farming with the addition of liquid organic supplements. Liquid organic supplements (SOC) or also called probiotics contain Lactobacillus sp, Azetobacter sp, Basiluss sp, vitamins, and minerals. SOC can increase antibodies, reduce stress levels, suppress the onset of disease, help stimulate appetite, and accelerate the growth of broiler chicken. Broilers are divided into 4 treatments female broilers without SOC, male broilers without SOC, female broilers with the addition of SOC, and treatment of male broilers with the addition of SOC. Based on the results and discussion the highest PBB is obtained by male chicken with SOC. Feasibility analysis shows that all treatments are feasible, B/C (3.11) and R/C (3.18) values of treatments added by SOC are higher than treatments without SOC.Keywords: Broiler, Feasibility Analysis, SOC
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Fafiolu, A. O., and J. O. Alabi. "Diet matrix of stored proprietary feeds: Implications on growth response, health status and carcass yield of broiler chickens." Nigerian Journal of Animal Production 47, no. 4 (2020): 139–57. http://dx.doi.org/10.51791/njap.v47i4.82.
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This study examined growth responses, health status and carcass yield of broiler chickens from 22 to 42 days of age provided with proprietary finished feeds (4 brands; P, Q, R & S) exposed to two storage conditions (lit or dark room) for four weeks. Four hundred and eighty chicks (802.7±14.3 g), at 21-day-old, were randomly allocated to eight groups of 60 chicks each (6 replicates; 10 birds each). Broiler chickens were fed one of the eight resultant diets from storage exercise for 21 d. Results revealed that performance of finishing broiler chickens were influenced by both the main and interaction effects of feed brands and storage condition. Chickens fed feeds stored in dark room gained 5.39% heavier weight with better FCR (5.07%) and higher (P<0.001) crude fat (2.97%), protein (2.36%), fibre (2.43%) and ash (3.89%) digestibilities compared to birds fed feeds stored in lit room. Chickens fed with feed R had higher (P<0.05) PCV, RBC, total protein, albumin, and uric acid. Duodenal and ileal villus height (VH) and villus to crypt ratio (VCR) were higher in broilers fed feed R stored in dark room, whereas jejunal VH and VCR were higher in birds fed feed Q stored in dark room. Salmonella and lactobacillus counts were greater in birds fed feeds R and S stored in lit room, respectively. Higher (P=0.008) dressed yield was obtained in broilers fed feed S stored in lit room. The study revealed that exposure of similar or different finished feeds to varying storage conditions would impart broiler's performance differently.
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Nurmi, Aisyah, Melia Afnida Santi, Nurainun Harahap, and Muharram Fajrin Harahap. "PERSENTASE KARKAS DAN MORTALITAS BROILER DAN AYAM KAMPUNG YANG DI BERI LIMBAH AMPAS PATI AREN TIDAK DIFERMENTASI DAN DIFERMENTASI DALAM RANSUM." JURNAL ILMIAH PETERNAKAN TERPADU 6, no. 3 (2019): 134. http://dx.doi.org/10.23960/jipt.v6i3.p134-139.
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The objectives of this research were to study the percentage of carcass of broiler and native chicken given arenga waste fermentation by Saccaromyces cerevisiae and to study arenga waste unfermentation in the ration. Sixty of broiler chickens Arbor Acres strain and sixty native chickens were divided into four dietary treatments and three replications (10 birds/replicate). The design of this experiment was completely randomized design factorial 2x2, with factor A was feeding (A1 : arenga waste unfermented, A2 : arenga waste fermented), and factor B was chicken species (B1:native chickens, B2:broilers). The variables observed were: (1) body weight, (2) carcass, (3) percentage of carcass, and (4) Mortality.The purposes of this study were to look at the effectiveness of rations and species of chicken used for the percentage of carcass and mortality. The results showed that there was no interaction (P> 0.05) between the fed arenga waste fermented or unfermented 2.5% in the ration,and the type of chicken on weight, carcass and carcass percentage, but there was an interaction on mortality (P<0.01). The fed had no significant (P>0,05) effect on weight, carcass, and carcass percentage, but percentage, but significant effect (P <0.05) on mortality. Types of chickens had a significant effect (P <0.05) on weight, carcass, percentage of carcass and mortality. The mortality rate with unfermented arenga waste was high enough, especially in broiler chickens, but it can be tolerated on native chicken and broilers with saccaromyces cerviseae fermented arenga waste. Keywords : Arenga Waste, Fermentation Arenga Waste, Native Chickens, Broiler
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Raphael, Wafar James, Ojinnaka Ebere Perpetual, Tarimbuka Isa Luka, Iliya Samuel Deacon, and Shehu Ibrahim Isa. "Growth Performance, Carcass Characteristics and Serum Biochemistry of Broiler Chicken Fed Graded Levels of Sun-Dried Irish Potato Peel Meal." Turkish Journal of Agriculture - Food Science and Technology 5, no. 5 (2017): 525. http://dx.doi.org/10.24925/turjaf.v5i5.525-529.1070.
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An experiment was conducted to evaluate the effect of substituting different levels of sun-dried Irish potato peel meal (SPPM) for maize in diets of broiler chickens. Five diets in which SPPM was replaced with 0 (0SPPM), 25 (25SPPM), 50 (50SPPM), 75 (75SPPM) and 100% (100SPPM) of maize in starter and finisher diets for a 8 week period using broiler chickens were examined. A total of 300 two weeks old broilers chicks Anak 2000 were randomly allotted to five experimental diets with six pen per treatment and 10 birds chicks per pen. Body weight and feed intake of broilers, and feed conversion ratio were determined at the beginning and 56th day of the experiment respectively. On day 56, four broilers from each pen were selected and slaughtered to determine some carcass characteristics and serum biochemistry. The result of growth performance showed that 100SPPM decreased daily weight gain of chickens when compared to other SPPM levels (P
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Zekeri, Okpanachi Joseph, Okpe, et al. "Performance and haematological indices of broiler chickens fed varied inclusion level of palm kernel cake." GSC Biological and Pharmaceutical Sciences 21, no. 1 (2022): 208–14. http://dx.doi.org/10.30574/gscbps.2022.21.1.0380.
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A total of one hundred and forty four (144) broiler chickens in a 42-day trial were used to evaluate the effect of graded levels of palm kernel cake on the performance and haematological characteristics of broilers. The broilers were randomly allotted to four treatments with 0%, 10%, 20% and 30 % PKC inclusion levels designated as treatments 1, 2, 3 and 4 respectively in a Completely Randomized Design (CRD). Each treatment had three (3) replicates with twelve (12) birds per replicate. Growth performance showed higher significant (P<0.05) values of 2073.68 g, 1874.39 g, 44.63 g and 101.49 g respectively for final weight, weight gain, daily weight gain and daily feed intake from birds fed 30 % PKC. Value ranges of 32.14 % to 34.67 % 10.36 g/dl to 11.37 g/dl, 3.17 to 3.49 x1012/l were obtained for packed cell volume, haemoglobin, and red blood cell in birds fed the control and 30 % PKC based diets respectively. This implied PKC has the potential to improved growth performance and haematology of boilers chicken. It was concluded that inclusion of PKC in the broiler’s diets significantly improved the performance and haematological parameters of the broiler chickens therefore should be included in the formulation of broilers diets for up to 30 %.
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Harrison, Sylvia Jana, Mayoba Barbara Moono, and Idowu Kolawole Odubote. "Production Systems and Management Practices of Chicken Populations in Zambia." Sustainable Agriculture Research 13, no. 1 (2024): 61. http://dx.doi.org/10.5539/sar.v13n1p61.
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The study was carried out to describe the population, population dynamics, production systems and management practices of chicken types reared in Zambia, using the 2017/2018 livestock and aquaculture census data provided by the Zambia Statistics Agency and the Ministry of Fisheries and Livestock. Data on the chicken types - Indigenous, Broiler and Layer, was analyzed for both quantitative and qualitative parameters. The population estimates for the chickens were 15,313,780, 6,078,694 and 742,981 for indigenous, broiler and layer, respectively. Flock dynamics could not be ascertained conclusively due to inadequate information. Chicken ownership was significantly skewed towards the male gender for broilers (67%) and layers (79%) while almost equal for the indigenous chickens. Indigenous chickens were more prominent in provinces with high agricultural production (Southern, Central, and Eastern at 51%). Broilers and Layers were more prominent in provinces with commercial centres (Copperbelt and Lusaka at 68% and 75% respectively). The main purpose of rearing indigenous chickens was mainly sales for income (66.1%) and home consumption (32.3%). The main production systems were found to be traditional for indigenous chickens (87%) and intensive for broiler and layer chickens (70.3% and 44%, respectively). The main feeding practices were free-range feeding (80.6%) and free-range with supplementation (17.4%) for indigenous chickens). Diseases notably, Newcastle was found to be debilitating and a great hindrance to livestock production and productivity. The data collection instrument will require fine-tuning to obtain more technical details on production and productivity and better estimate the population dynamics.
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Herlina, Herlina, La Ode Nafiu, and Muhammad Amrullah Pagala. "BOBOT TETAS DAN FERTILITAS PADA AYAM KAMPUNG DAN HASIL PERSILANGANNYA." Jurnal Ilmu dan Teknologi Peternakan Tropis 3, no. 3 (2016): 32. http://dx.doi.org/10.33772/jitro.v3i3.2566.
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This study aims to determine the performance of chicken and cross breeding results with laying hens and broilers. A total of 3 male chickens and 15 chickens Kampung females, 3 males laying chickens and 10 chickens laying females, and 3 chickens stud broiler. The variables observed were egg weight, fertility, hatchability, hatching weight. Data were analyzed with General Linear Model (GLM). Data on hatch weight, egg weight, fertility and hatchability were analyzed based on different breed. If there is a difference between treatments then a further test with Duncan Multiple Test is performed. The results showed that the performance of chicken and crossbreeding with laying and broiler chickens had significant effect (P <0,05) on egg weight, fertility, hatchability based on different nation and weight of hatch, body weight, heterosis and growth based on breed and different sex. Key Word : Performance, Crossbreeding, Kampung Chicken, Broiler, Layer.
Dissertations / Theses on the topic "Broilers (Chickens)"
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Nagaraj, Manonmani. "Evaluation of nutrition and management factors in the etiology of pododermatitis in broiler chickens." Auburn, Ala., 2006. http://repo.lib.auburn.edu/Send%206-15-07/NAGARAJ_MANONMANI_39.pdf.
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Mafiri, Matseko Nkele. "Effect of supplementing diets with effective microorganisms on intake, growth and carcass characteristics of ross 308 broiler chickens." Thesis, University of Limpopo, 2014. http://hdl.handle.net/10386/1390.
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Thesis (M.Sc. (Animal Production)) -- University of Limpopo, 2014<br>Two experiments were conducted to determine the effects of supplementing diets with effective microorganisms on intake, growth and carcass characteristics of Ross 308 broiler chickens. The first experiment determined the effect of supplementing diets with effective microorganisms on performance of unsexed Ross 308 broiler chickens aged one to three weeks. Two hundred unsexed day-old chicks were randomly assigned to five treatments with four replications, each replication having ten birds. A complete randomized design was used. The chickens were fed a grower diet supplemented with 0 (EM0), 30 (EM30), 50 (EM50), 70 (EM70) or 100 (EM100) ml of effective microorganisms per litre of water. Effective microorganism supplementation did not improve (P>0.05) diet and metabolisable energy intakes of the chickens. Effective microorganism supplementation reduced (P<0.05) growth rate and live weight of the chickens. Poorer (P<0.05) feed conversion ratios were observed in chickens supplemented with effective microorganisms. However, effective microorganism supplementation improved (P<0.05) crude protein retention of the chickens. Supplementation with effective microorganisms reduced (P<0.05) mortality rate of the chickens from 10 to 0 %.
The second experiment determined the effect of supplementing diets with effective microorganisms on performance of male Ross 308 broiler chickens aged 22 to 42 days. The chickens were randomly allocated to five treatments with four replications, each replication having 10 birds. The chickens aged 21 days, weighing 474 ± 2g, were allocated to the treatments in a complete randomized design. The chickens were fed a grower diet supplemented with 0 (EMM0), 30 (EMM30), 50 (EMM50, 70 (EMM70) or 100 (EMM100) ml of effective microorganisms per litre of water. Effective microorganism supplementation did not improve (P>0.05) intake, DM digestibility, metabolisable energy, feed conversion ratio, fat pad weight and meat sensory attributes of the chickens. Effective microorganism supplementation reduced (P<0.05) growth rate, live weight and carcass weight of the chickens. However, effective microorganism supplementation improved (P<0.05) crude protein retention and crude protein content of meat of the chickens. Supplementation with effective microorganisms reduced (P<0.05) mortality of the chickens from 5 to 0 %.
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It is concluded that effective microorganism supplementation to the diets of Ross 308 broiler chickens reduced growth rate and live weight of the chickens. However, effective microorganism supplementation improved crude protein retention and crude protein content of the meat of broiler chickens. Supplementation with effective microorganisms reduced mortality of the chickens to zero.
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Joubert, Sunett. "The effect of genotype and rearing system on chicken meat quality." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85783.
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Thesis (MScFoodSc)--Stellenbosch University, 2013.<br>ENGLISH ABSTRACT: Modern consumers are health conscious and are shifting towards more naturally produced products such as free range chicken. Commercial broiler strains are not suitable for free range rearing and an alternative genotype is needed that will serve the South African market with the acceptable meat quality as a broiler. The objective of this study was to investigate the effect of production system (free range and intensive reared) and genotype (Broiler (COBB™), Ross 308 X Potchefstroom Koekoek hybrid and Potchefstroom Koekoek) on chicken meat quality. This was quantified on the morphological, physical (pH, colour, drip and cooking loss, water holding capacity and tenderness), chemical composition (moisture, protein, fat, ash contents and fatty acid profile), sensory quality and consumer preference of various chicken meat portions.
The results of this study indicate that genotype had a more pronounced effect than production system on the morphological and growth properties of chicken meat, as well as on the sensory characteristics and consumer preference. The broilers had the best (P ≤ 0.05) feed conversion ratio (FCR), highest average daily gain (ADG) and European production efficiency factor (EPEF), followed by the Hybrid and then the Potchefstroom Koekoek. For each genotype, the free range chickens produced heavier (P ≤ 0.05) live weights than intensively reared chickens. Despite the poorer growth performance and efficiency of the medium growing Hybrid birds, they had less mortality and fewer leg disorders than the broiler. Additional to these factors, the Hybrid Free Range had higher thigh, drumstick and wing yields (P ≤ 0.05) than the broiler. When investigating the correlation between the chemical and sensory data, it was observed that the Hybrid scored significantly higher (P ≤ 0.05) in both flavour and aroma than the Broiler and Koekoek genotypes for both production systems.
For colour, pH and polyunsaturated to saturated fatty acid ratio (PUFA:SFA), the effect of production system was more pronounced than the effect of genotype. Rearing chickens in a free range environment increased the PUFA:SFA ratio (P ≤ 0.05), making it beneficial to human health. Free range rearing resulted in lower muscle pHu (P ≤ 0.05), darker (L* value) (P ≤ 0.05), less red and yellow (a* and b* value) (P ≤ 0.05) chicken meat. It also influenced the chemical composition in different carcass portions; for example, a lower fat content in the thigh and higher protein in the breast of the Broiler.
Correlation with the sensory results indicated that juiciness, tenderness, chicken aroma and chicken flavour are the main drivers of liking for consumer’s preference towards chicken meat.
The consumers predominantly preferred the Hybrid (P ≤ 0.05) in a blind tasting session, but when information was given on the production system of a chicken product, the consumers lean more towards a free range reared product than an intensive reared product. This indicates that consumer perception plays an immense role in consumer decision making. Cluster analysis was also performed to ascertain whether the consumers differed in their degree of liking of the intrinsic character of the respective chicken samples. Three different clusters of consumers were identified: 1) Consumers that prefer free range reared chicken meat, 2) Consumers that prefer intensively reared chicken meat, 3) Consumers that prefer both free range and intensive reared chicken meat.
In conclusion, the Hybrid seems to be a viable option for free range production systems in South Africa, without negatively affecting the overall quality of the meat or consumer acceptance.<br>AFRIKAANSE OPSOMMING: Moderne verbruikers is baie meer gesonheidsbewus en verkies meer natuurlik geproduseerde produkte soos vrylopende (free range) hoenders. Die kommersiële braaikuiken is nie geskik vir vrylopende produksie nie en `n ander genotipe word benodig wat die Suid-Afrikaanse mark sal kan voorsien met aanvaarbare vleiskwaliteit vergelykbaar met dié van die braaikuiken. Die doel van hierdie navorsing was om die effek van produksiestelsel (vrylopend en intensief) en genotipe (braaikuiken (COBB™), Potchefstroom Koekoek en Ross 308 X Potchefstroom Koekoek kruising) op die morfologiese, fisiese (pH, kleur, drip- en kookverlies, waterhouvermoë en taaiheid), chemiese samestelling (vog-, proteïen-, vet-, asinhoud en vetsuurprofiel), sensoriese kwaliteit en verbruikersaanvaarbaarheid van verskeie hoender vleis porsies te bepaal.
Hierdie navorsing het getoon dat genotipe `n groter invloed gehad het as produksiestelsel op die groei en morfologiese eienskappe van die hoenders, asook op die sensoriese eienskappe en verbruikersaanvaarbaarheid. Die braaikuiken, gevolg deur die Ross X Koekoek kruising en dan die Koekoek, het die beste (P ≤ 0.05) voeromsetverhouding (FCR), gemiddelde daaglikse toename (GDT) en Europese produksie effektiwiteitsfaktor (EPEF) getoon. Vir elke genotipe het die vrylopende hoenders swaarder (P ≤ 0.05) lewende massa by slag getoon. Ten spyte daarvan dat die Ross X Koekoek kruising swakker groei en effektiwiteitsresultate getoon het, het hulle laer mortaliteite en minder been breuke en beserings as die braaikuiken gehad. Die Ross X Koekoek kruising wat vrylopend groot gemaak is, het ook swaarder dy, boud en vlerkie massa (P ≤ 0.05) as die braaikuiken getoon.
Die navorsing het ook getoon dat kleur, pH en die poli-onversadigde tot versadigde vetsuur verhouding (PUFA:SFA) meer beïnvloed is deur die effek van produksiestelsel as genotipe. Die hoenders wat in ʼn vrylopende omgewing grootgemaak is se PUFA:SFA verhouding is hoër as dié van intensiewe boerdery, wat dit voordelig maak vir menslike gesondheid. Vrylopende hoenders se vleis is donkerder (L*) (P ≤ 0.05) en het ook laer rooi, geel (a* en b*) en pH (P ≤ 0.05) waardes getoon. Produksiestelsel effek het ook variërende chemiese waardes in verskillende karkas porsies tot gevolg gehad: ʼn laer vetinhoud is gevind in die dy en ʼn hoër proteïeninhoud in die borsies van die braaikuikens wat vrylopend grootgemaak is.
Korrelasies met die sensoriese data het ook getoon dat sappigheid, taaiheid en hoendervleis geur die grootste dryfvere is in verbruikersaanvaarbaarheid. Tydens die verbruikerstoetse waar die verbruikers die gaar hoendervleis blind geproe het, het die verbruikers oor die algemeen meer gehou van die Ross X Koekoek kruising in vergelyking met die ander hoender genotipes (P ≤ 0.05), maar sodra inligting oor die verskillende produksiestelsels gegee is, het die verbruikers aangedui dat hulle hoenders wat vrylopend groot gemaak is, verkies. Dit dui daarop dat persepsies ʼn baie belangrike rol speel in die verbruiker se finale besluitnemingsproses. Statistiese segmentasietegnieke is ook op die data uitgevoer ten einde te bepaal of verbruikers in groepe verdeel kan word wat betref hul voorkeur van die sensoriese of intrinsieke eienskappe van die hoenderprodukte. Drie verskillende groepe is geïdentifiseer, nl. verbruikers wat 1) vrylopende hoender vleis verkies; 2) intensiewe hoender vleis verkies; 3) beide vrylopende en intensiewe hoender vleis verkies.
In die lig van bogenoemde resultate wil dit voorkom of kruisteling tussen die gewone braaikuiken en die Potchefstroom Koekoek ʼn moontlike opsie is vir die Suid-Afrikaanse vryloop hoenderbedryf. Hierdeur word daar van vrylopende produksie stelsels gebruik gemaak sonder om die vleiskwaliteit of gebruikers aanvaarbaarheid negatief te beïnvloed.
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Mohlapo, Teboho Daniel. "Effect of Hoodia Gordonii meal supplementation at finisher stage on productivity and carcass characteristics of Ross 308 broiler chickens." Thesis, University of Limpopo, 2009. http://hdl.handle.net/10386/496.
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Thesis (Bsc. (Animal production)) --University of Limpopo, 2009.<br>Two experiments were conducted to evaluate the effect of Hoodia gordonii meal supplementation at finisher stage on productivity and carcass characteristics of Ross 308 broiler chickens. Experiment 1 examined the effect of levels of Hoodia gordonii meal supplementation of grower diet fed to Ross 308 broiler chickens at the finisher stage (30 – 42 days of age) on productivity and carcass characteristics in a 12 day experimental period. The experiment was a completely randomized design with a 2 (two sexes of chickens) x 6 (levels of Hoodia gordonii meal [0, 100, 200, 300, 400 or 500 mg]) factorial arrangement of treatments in which three hundred and sixty broiler chickens at finisher stage were randomly allocated to twelve treatments with three replicates of ten birds each. Level of Hoodia gordonii meal supplementation had no effect (P>0.05) on diet intake, intake as percentage of live weight, growth rate, feed conversion ratio, live weight at 42 days of age and mortality of broiler chickens at finisher stage. All carcass characteristics were not affected (P>0.05) by the treatments except fat pads. Chickens given a daily dose of 300 mg of Hoodia gordonii meal had lower (P<0.05) fat pad weights than unsupplemented ones. Male broiler chickens had higher (P<0.05) feed intake and heavier drum sticks than female broiler chickens.
Experiment 2 examined the effect of Hoodia gordonii meal dose interval at finisher stage in a 2 (two sexes of chickens) x 3 (dosage intervals) factorial, complete randomized design that involved three hundred and sixty chickens that were randomly allocated to six treatments with six replicates of ten birds each. Broiler chickens were fed either a grower diet without Hoodia gordonii meal; grower diet with 300 mg of Hoodia gordonii meal/ bird supplemented everyday for 12 days; or grower diet with 300 mg of Hoodia gordonii meal/ bird supplemented twice, on 30th and 36th days of age. Hoodia gordonii meal dose interval had no effect (P>0.05) on dry matter feed intake, intake as percentage of live weight, growth rate, live weight at 42 days of age, feed conversion ratio, mortality and all carcass characteristics except fat pad of broiler chickens. Daily dosing with 300 mg of Hoodia gordonii meal/ bird reduced (P<0.05) fat pad weights of broiler chickens by 18 percentage points. Male broiler chickens had higher (P<0.05) feed intake, nitrogen digestibility, nitrogen retention and live weight than female broiler chickens.
It is concluded that chickens given a daily supplement of 300 mg of Hoodia gordonii meal had lower fat pad weights than unsupplemented ones. This could not be explained in terms of differences in feed intake, digestibility, or growth rate.
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Kafri, Ilan. "Skin breaking strength in broiler chickens." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54306.
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A procedure was developed to examine factors contributing to skin strength of meat-type chickens. Skin breaking strength was initially measured in lines of chickens divergently selected for high (H) and low (L) juvenile body weight, their reciprocal crosses (HL and LH), and an F₂ generation derived from HL and LH matings. Skin of chicks from the LL line was weakest, that from the HH and LH matings strongest, and that from HL and F₂ matings was intermediate. Percentage heterosis for breaking strength was significantly positive while percentage recombination was not significant.
Skin breaking strength and protein, fat, moisture, and total collagen concentrations of skin from the breast, thigh, and back of male and female commercial broilers were then examined in response to diets containing relatively wide or narrow ratios of calories to protein (C:P). Comparisons were made at 28, 42, and 56 days of age. Chickens fed diets containing wider C:P ratios had weaker skin than those fed diets with narrower C:P ratios, with the differences being greater at older than at younger ages. Males had stronger skin than females. Among body sites, breast skin was stronger than thigh skin with that from the back being intermediate in strength. Skin breaking strength did not appear to be consistently associated with either the protein, fat, or collagen concentrations in the skin.
Skin from broiler chicks fed diets with differing C:P ratios was also examined histologically. Males had stronger and thinner skin than females, with the differences in thickness due primarily to differences in the thickness of the hypodermis. Regardless of sex, feeding diets containing wider C:P ratios resulted in weaker and thicker skin. The thicker skin was associated with an increase in the thickness of the hypodermis and a decrease in the thickness of the dermis and epidermis. With the exception of differences between back and thigh skin, increases in breaking strength occurring between skin from different sites were associated with a reduction in total skin thickness and in the thickness of the hypodermis. It was concluded that increased hypodermis thickness and/or decreased thickness of the dermis and epidermis reduced skin strength.
Two experiments were conducted in which skin strength was examined in relation to heat stress and supplemental ascorbic acid. In the first experiment, chicks fed diets containing 0 or 100 mg of ascorbic acid per kg of diet were subjected to either a constant ambient temperature of 23C, a constant ambient temperature of 32C, or a treatment consisting of 32C from 1600 to 1200 hr and 400 from 1200 to 1600 hr (32/400). Both heat stress and supplemental ascorbic acid tended to increase collagen concentrations in the skin, but differences in breaking strength were inconsistent in response to these treatments. Supplemental ascorbic acid, however, partially alleviated reductions in body weight due to heat stress but did not decrease body temperatures of heat-stressed chicks.
In the final experiment, diets containing either 0, 200, or 400 mg/kg of supplemental ascorbic acid were fed to chicks maintained at ambient temperatures of 23 and 34C. Contrary to previous observations, ascorbic acid failed to ameliorate the depressive effect of heat stress on body weight. Supplemental ascorbic acid tended to reduce adrenal, bursa of Fabricius, and spleen weights but had no effect on heterophil and lymphocyte numbers or ratios. Adrenal ascorbic acid concentrations were not significantly affected by supplemental ascorbic acid and plasma ascorbic acid levels were inconsistent among treatment groups. Neither supplemental ascorbic acid nor heat stress significantly influenced skin strength. It was concluded that supplemental ascorbic acid was not beneficial in improving skin strength in commercial broiler chicks.<br>Ph. D.
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Prince, Siliga Hulisani. "Modelling the broiler performance under small-scales and semi commercial management condition." Thesis, Port Elizabeth Technikon, 2002. http://hdl.handle.net/10948/110.
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Introduction : World poultry meat consumption consists of three major segments: broilers, turkeys, and other poultry which includes spent egg layers, spent breeder hens/males, ducks, geese, guinea-fowl, pheasants, quail, ratites, ostriches and emus. Broilers clearly dominate the world poultry consumption contributing about 70 percent to the world poultry market. Turkeys account for about eight percent while other poultry provides the balance of 22 percent (Roenick, 1998). The world broiler industry has been, and continues to be a very dynamic industry. It has been typified with unprecedented growth in terms of production. In 1961, the world produced 6.5 billion broilers. By 1990, the total annual production was a little over 27 billion broilers and by 1996, total world production had grown to 35.3 billion (Van der Sluis., 1999). This represents a fivefold increase in 35 years, and it has not stopped growing since, with world production surpassed 38 billion in 1998 (Van der Sluis., 1999). In Africa the human population was estimated to be 819.9 million, while the total poultry population of the continent was estimated as 1.133 million chickens, 15 million ducks and seven million turkeys in 1998. Production scale being 1.781701 metric tones (MT) of hen eggs, 2.269000 MT of chickens’ meat, 32.824MT of turkey meat and 52.989MT of duck meat (Gueye, 2000). Commercial poultry products are also imported and exported. For example, 12.000 metric tons of poultry meat was estimated to have been exported from South Africa in 1999, whereas 87.000 and 10.000 metric tons of poultry meat was imported into South Africa and Egypt, respectively (Gueye, 2000). In South Africa poultry production is moving toward the 21st century with the potential for increased development being greater than any other sector of the agricultural industry. The small-scale to medium-scale or semi-commercial farmer is becoming a role-player that needs to be serviced by the poultry industry (Fourie, 2000). The industry will have to take up the challenges that are facing an entrepreneur starting with a poultry venture. The poultry industry has developed from a humble beginning at the turn of the century into a multi-million Rand enterprise where protein is provided through the commercial and small marketing sector (Fourie, 2000). Some of the larger commercial companies market three million birds per week. It is estimated that the commercial company sector is responsible for 75 to 85 percent of production and marketing of white meat in this country whereas the small-scale and medium-scale or semi commercial poultry production enterprises provide 20 to 25 percent of the white meat through the sales of slaughtered and live poultry sale to rural, peri-urban and urban settlements (Fourie., 2000). Small-scale and semi-commercial broiler production is developed by entrepreneurs who buy day-old chicks from the big commercial hatcheries, rear them to the age of five to eight weeks and sell them through a marketing network or small outlets. The small-scale consist of farmers who reared 100 t0 1000 chickens per batch and semi-commercial consist of farmers who reared 1000 to 5000 chickens per batch. These types of farmers acquire very little technical backup in terms of a training and services center where assistance is available every day of the week. The broiler industry requires birds that are of commercial crosses selected for their ability to grow very fast and produce a good quality carcass in the shortest time frame. The small farmers purchase broiler stock, as the day-old chicks from commercial hatcheries and reared them up to six to eight weeks before slaughtered or sold as live chickens. The selling of live chickens through a network outlets system is becoming an industry that is growing at a steady pace, as household food security is becoming important to communities (Fourie, 2000). The price of feed is the single most expensive item on the list of expenses of a farmer because of their financial constraints. The small-scale and semicommercial broiler farmer is faced with the problem of buying small quantities of feed at an inflated price. The problem can be alleviated by groups of small farmers joining co-operative and buying feeds in bulk from suppliers and redistributing to small farmers. The community co-operative can once again play a major role in the distribution of small amounts of feed to its member. The biggest challenge is to provide training with a “hands on” approach. It will be ideal to have a training center where small farmers can be trained in all aspects of poultry production. The training facility will have to operate as a fully operational poultry unit with no risks to bio-security of a commercial enterprise. Training will have to be provided in aspects like hatchery, housing, broilers and record management depending on the farmer’s needs. There is also a need for the research on broiler performance under small-scale and semi commercial farming. Research in this sector of poultry production should look in appropriate feeds, feeding, technology, genotype and performance of genotypes under the system. Emphasis in this study will be on growth patterns and performance of the Ross hybrids as a modern broiler under small-scale and semi commercial management condition. Aspect of the environment such as age, type of feeds and feeding methods, housing, seasons, lighting and genotype will be taken into consideration. The result of the study will provide a realistic database for mathematical modeling of production response and guideline for management planning in small-scale and semi-commercial management condition. Also this result will be important to broiler breeders, to determine the suitability of the modern broiler to small-scale and semi commercial management conditions. The objective of the study was to evaluate the mathematical model that could describe the performance of broilers under the small-scale and semi-commercial management conditions.
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Nembilwi, Daniel. "Evaluation of broiler performance under small-scale and semi-commercial farming conditions in the Northern Province." Thesis, Port Elizabeth Technikon, 2002. http://hdl.handle.net/10948/92.
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Introduction: In the Northern region of the Northern Province, there is an increase in the number of small-scale and semi-commercial farms in all sectors of agriculture. This includes the production of grains, vegetables, fruits and livestock. Broiler production seemed to be a much-preferred alternative of development in community based projects and emerging farmers have shown keen interest. This is because broiler production requires less space than ruminants and is ready for human consumption within a very short period of time. Poultry production provides a constant source of income and protein with a big customer demand. By the year 2000, broiler production is expected to reach 4000 million and 7.5 million tons of poultry feeds in the world. Many countries have initiated programs aimed at improving small-scale poultry as a means of helping to bring socio- economic benefits to rural communities (Panda, 1989). In order to feed the ever rising population of 4.9 million in the Northern Province (1996 Census), there must be an increase in the production of broilers as a primary source of top quality animal protein. With the high unemployment rate (46%) in the Northern Province, self- employment projects are needed which comply with agro- processing. More than 90 community projects based on poultry production in the Northern region of the Northern Province had been established in order to reduce the high rate of unemployment. Today more people have engaged themselves in community projects especially in poultry production than ever before. Some of the constrains of broiler production at both small-scale and semi-commercial farming condition includes inadequate ventilation system. Lack of suitable health care facilities and frequently the absence of efficient marketing structures form part of the obstacles to the rapid development of poultry production. Feed costs which remain the highest input cost in the production of broilers represent between 60 to 70% or more of the total costs of broiler productions (Benyi and Habi, 1998). Lack of management skills and training for small and semi-commercial farmers makes it difficult to obtain optimum performance. The objective of this study is to evaluate the performance of broilers as influenced by environmental factors under small.
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Aitchison, Mia. "Energy efficiency and nutrient partitioning in the modern broiler chicken." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=225709.
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Iji, Paul Ade. "Natural development and dietary regulation of body and intestinal growth in broiler chickens." Title page, contents and summary only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phi25.pdf.
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Corrigenda inserted behind title page. Bibliography: leaves 275-306. The pattern of body growth and intestinal development of an Australian strain of broiler chicken, the Steggles x Ross (F1) in response to different diets was studied. Five experiments were designed to examine the pattern of growth and mechanisms involved. In four other experiments, the mechanisms underlying the gross response of the broiler chicks to dietary ingredients, anti-nutritive factors and growth enhancers were examined. Results indicated that a rapid development of the small intestine preceded significant overall body growth. Body growth would, however, depend more on the various physiological events such as those related to mucosal growth and renewal, digestive enzyme function, and nutrient transport. Some of the differences observed in productivity of broiler chickens on different diets were traced to events at the intestinal level.
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Molepo, Lephai Sarah. "Effect of moringa seed meal supplementation on productivity and carcass characteristics of ross 308 broiler chickens." Thesis, University of Limpopo, Turfloop Campus, 2014. http://hdl.handle.net/10386/1340.
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Thesis (MSc. Agriculture (Animal Production)) -- University of Limpopo, 2014<br>Two experiments were conducted to determine the effect of moringa seed meal supplementation on productivity and carcass characteristics of Ross 308 broiler chickens. The first experiment determined the effect of moringa seed meal supplementation on productivity of Ross 308 broiler chickens aged one to 21 days. Two hundred and fifty unsexed day-old Ross 308 broiler chicks were randomly allocated to five dietary treatments, replicated five times, and each replication having 10 chickens. A completely randomized design was used. The chickens were fed on a grower diet supplemented with 0 (M0), 5 (M5), 10 (M10), 15 (M15) and 20 (M20) g of moringa seed meal/bird/day. Moringa seed meal supplementation had no effect (P>0.05) on feed intake, metabolisable energy intake, nitrogen retention, feed conversion ratio and live weight of unsexed Ross 308 broiler chickens. Moringa seed meal supplementation improved (P<0.05) growth rates of unsexed Ross 308 broiler chickens aged one to 21 days. A moringa seed meal supplementation level of 13.3 g/kg DM feed optimized growth rate of Ross 308 broiler chickens aged one to 21 days.
The second experiment determined the effect of moringa seed meal supplementation on productivity and carcass characteristics of female Ross 308 broiler chickens aged 22 to 42 days. The chickens weighing 558 ± 10 g/bird were randomly allocated to five treatments with five replications having 10 birds. The chickens, aged 21 days, were allocated to the treatments in a completely randomized design. The chickens were fed on a grower diet supplemented with 0 (FM0), 5 (FM5), 10 (FM10), 15 (FM15) and 20 (FM20) g of moringa seed meal per kg DM. Moringa seed meal supplementation had no effect (P>0.05) on feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy intake, carcass weight, breast meat weight, abdominal fat pad weight, liver weight, heart weight, thigh weight, meat flavour, juiciness and tenderness of female Ross 308 broiler chickens. However, moringa seed meal supplementation improved (P<0.05) nitrogen retention and gizzard weights of female Ross 308 broiler chickens.
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It was concluded that moringa seed meal supplementation improved growth rate of unsexed Ross 308 broiler chickens aged one to 21 days. Similarly, moringa seed meal supplementation increased nitrogen retention and gizzard weights of female Ross 308 broiler chickens aged 22 to 42 days.
Books on the topic "Broilers (Chickens)"
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Humane Society of the United States. Farm Animals & Sustainable Agriculture Section., ed. Chickens under contract: The U.S. broiler industry today. The Society, 1998.
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Gubanov, A. G. Ėkonomika proizvodstva mi͡a︡sa, t͡s︡ypli͡a︡t-broĭlerov na Severnom Kavkaze. Izd-vo Rostovskogo universiteta, 1988.
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B, Leclercq, and Whitehead C. C, eds. Leanness in domestic birds: Genetic, metabolic, and hormonal aspects. Published by arrangement with the Institut national de la recherche agronomique by Butterworths, 1988.
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International Poultry Broiler Nutritionists' Conference (2nd 2001 Rotorua, N.Z.). Poultry beyond 2005: Carving a great future : proceedings of the 2nd International Poultry Broiler Nutritionists' Conference, Rotorua, New Zealand, February 2001. Published jointly by the Poultry Industry Association of New Zealand and the New Zealand Institute for Crop & Food Research, 2001.
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Goodwin, John W. Supply and demand responses in the U.S. broiler industry. Arkansas Agricultural Experiment Station, 1996.
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Council, Farm Animal Welfare. Report on the welfare of broiler chickens. MAFF, 1992.
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United States. Animal and Plant Health Inspection Service. Veterinary Services. Centers for Epidemiology and Animal Health. Clostridial dermatitis in U.S. commercial turkeys and broilers. U.S. Dept. of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Centers for Epidemiology and Animal Health, 2011.
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Harris, Clarence E. Improved methods and facilities for packing broilers. U.S. Dept. of Agriculture, Agricultural Marketing Service, 1986.
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Zabielski, Jan. Technologiczne i biofizyczne skutki napromieniania mięśni piersiowych kurcząt brojlerów. Wydawn. Akademii Rolniczej w Poznaniu, 1990.
Find full textBook chapters on the topic "Broilers (Chickens)"
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He, Wenliang, Peng Li, and Guoyao Wu. "Amino Acid Nutrition and Metabolism in Chickens." In Advances in Experimental Medicine and Biology. Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-54462-1_7.
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AbstractBoth poultry meat and eggs provide high-quality animal protein [containing sufficient amounts and proper ratios of amino acids (AAs)] for human consumption and, therefore, play an important role in the growth, development, and health of all individuals. Because there are growing concerns about the suboptimal efficiencies of poultry production and its impact on environmental sustainability, much attention has been paid to the formulation of low-protein diets and precision nutrition through the addition of low-cost crystalline AAs or alternative sources of animal-protein feedstuffs. This necessitates a better understanding of AA nutrition and metabolism in chickens. Although historic nutrition research has focused on nutritionally essential amino acids (EAAs) that are not synthesized or are inadequately synthesized in the body, increasing evidence shows that the traditionally classified nutritionally nonessential amino acids (NEAAs), such as glutamine and glutamate, have physiological and regulatory roles other than protein synthesis in chicken growth and egg production. In addition, like other avian species, chickens do not synthesize adequately glycine or proline (the most abundant AAs in the body but present in plant-source feedstuffs at low content) relative to their nutritional and physiological needs. Therefore, these two AAs must be sufficient in poultry diets. Animal proteins (including ruminant meat & bone meal and hydrolyzed feather meal) are abundant sources of both glycine and proline in chicken nutrition. Clearly, chickens (including broilers and laying hens) have dietary requirements for all proteinogenic AAs to achieve their maximum productivity and maintain optimum health particularly under adverse conditions such as heat stress and disease. This is a paradigm shift in poultry nutrition from the 70-year-old “ideal protein” concept that concerned only about EAAs to the focus of functional AAs that include both EAAs and NEAAs.
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Abioja, M. O., and J. A. Abiona. "Impacts of Climate Change to Poultry Production in Africa: Adaptation Options for Broiler Chickens." In African Handbook of Climate Change Adaptation. Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_111.
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AbstractGlobal climate change poses a great threat to poultry production. Greenhouse gases (GHGs) are released through both natural and anthropogenic sources into the atmosphere. Though poultry production contributes little to the release of GHGs, the subsector has been shown to be greatly affected by climate change and global warming. Poultry production as a major subsector of agriculture has provided the teeming population with a supply of needed animal protein in terms of meat and egg production all over the world. It is yet a major global employer of labor. Though it occupies a vantage position in meeting human needs, it is being threatened by climate change, especially in Africa where necessary structure to tackle the menace is nonexistent. Broiler chickens that are reared mainly for chicken meat cannot tolerate the high ambient temperature that prevails mostly in the tropical environment. Chickens are homeotherms that homeostatically regulate core body temperature within a narrow range. Elevated ambient temperature above thermal comfort zone, such as envisaged in climate change scenarios, will trigger series of neuroendocrine modulations that are detrimental to the welfare and productivity in broiler chickens. Such birds are said to be undergoing heat stress (HS). Negative effects of HS include reduced feed consumption, growth rate, feed digestion and efficiency, immunity, welfare, and survivability. Various adaptive measures that could be harnessed by broiler farmers, ranging from housing, feeding, watering, stocking, breeding for thermo-tolerant strains, thermal conditioning, use of phytochemicals, and much more, are reviewed upon in this chapter.
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Coon, Craig N. "Broiler Nutrition." In Commercial Chicken Meat and Egg Production. Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0811-3_16.
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Lacy, Michael P. "Broiler Management." In Commercial Chicken Meat and Egg Production. Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0811-3_43.
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Simm, Geoff, Geoff Pollott, Raphael Mrode, Ross Houston, and Karen Marshall. "Poultry breeding." In Genetic improvement of farmed animals. CABI, 2021. http://dx.doi.org/10.1079/9781789241723.0366.
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Abstract In this chapter, the major breeding goals for each of the poultry products (eggs and meat) are discussed. An outline on how the breeding and selection methods have been developed appropriately on chicken meat (broiler) and chicken egg sectors was also presented.
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Coon, Craig N. "Feeding Broiler Breeders." In Commercial Chicken Meat and Egg Production. Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0811-3_19.
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Bell, Donald D. "A Model Integrated Broiler Firm." In Commercial Chicken Meat and Egg Production. Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0811-3_42.
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Osepchuk, Denis, Andrey Svistunov, Tamara Nepshekueva, Natalya Agarkova, and Oleg Svitenko. "Corn Extract Effect on Broiler Chickens Productivity." In Fundamental and Applied Scientific Research in the Development of Agriculture in the Far East (AFE-2021). Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-91405-9_17.
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Meulemans, G., M. Decaesstecker, and G. Charlier. "Runting Syndrome in Broiler Chickens. Experimental Reproduction Studies." In Acute Virus Infections of Poultry. Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4287-5_19.
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Alali, Walid Q., and Charles L. Hofacre. "Preharvest Food Safety in Broiler Chicken Production." In Preharvest Food Safety. ASM Press, 2018. http://dx.doi.org/10.1128/9781555819644.ch4.
Full textConference papers on the topic "Broilers (Chickens)"
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Petričević, Veselin, Miloš Lukić, Zdenka Škrbić, et al. "COMPARATIVE ANALYSIS OF PRODUCTION AND SLAUGHTER PARAMETERS OF FAST-GROWING BROILER HYBRIDS." In 2nd International Symposium on Biotechnology. Faculty of Agronomy in Čačak, University of Kragujevac, 2024. http://dx.doi.org/10.46793/sbt29.24vp.
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This study aimed to explore how hybrid varieties impact broiler chickens’ production and slaughter performance. We applied standard rearing techniques over a 42-day period. The trial involved a total of 420 broiler chickens of the following hybrids: Cobb 500 and Ross 308. Weekly performance tests were conducted, assessing average daily gain, feed consumption, feed conversion rate, mortality, and European Poultry Efficiency Factor. After controlling for final body weights on the 42nd day, a random sample of 12 broilers per genotype, with an equal gender distribution, was selected for slaughter parameter analysis. Following slaughter traits were determined: pre-slaughter weight of chickens, slaughter yield, share of abdominal fat, chicken thigh circumference, and chest angle. The results revealed no significant difference in food consumption between the examined hybrids. Chickens of the Cobb 500 genotype exhibited significantly higher (p<0.01) gain and a more favorable feed conversion rate. Due to its better vitality, feed conversion rate, and gain, Cobb 500 chickens demonstrated significantly higher (p<0.01) European Poultry Efficiency Factor values. In contrast, Ross 308 chickens displayed statistically significantly lower (p<0.05) slaughter yield and chest angle values. At the same time, the proportion of abdominal fat and chicken thigh circumference showed no significant difference between the tested hybrids.
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Doskovic, Vladimir, Snežana Bogosavljevic-Boškovic, Zdenka Škrbic, et al. "EFEKAT ENZIMA PROTEAZE NA PRINOS I UDEO JESTIVIH PRATEĆIH PROIZVODA KLANJA PILIĆA HIBRIDA MASTER GRIS." In XXVI savetovanje o biotehnologiji sa međunarodnim učešćem. University of Kragujevac, Faculty of Agronomy, 2021. http://dx.doi.org/10.46793/sbt26.269d.
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The effect of supplemental protease (Ronozyme ProAct) in broiler diet on the weights and percentage yields of slaughter by-products of male and female medium-growing Master Gris broiler chickens was analysed. Fattening period lasted for 63 days. Broilers were assigned to 3 experimental groups, each consisting of 100 birds. Experimental groups differed in protease levels used in their diets: control broilers (C) received complete feeds (starter, grower and finisher) without supplemental protease; chickens in the experimental group E-I were given a diet containing 0.2% protease and crude protein levels reduced by 4% compared with the control group, whereas experimental E-II broilers were fed a diet supplemented with 0.3% protease and containing crude protein levels reduced by 6% compared with C birds. The analysis of the results showed that feeding treatments had a very small effect on the weights and proportion yields of edible by-products (with difference only in the percentage yield of liver relative to live weight between C and E-I broilers, P<0.05), whereas sex was found to affect almost all slaughter by-products (except abdominal fat weight and the percentage yield of gizzard relative to live weight, P>0.05).
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Eglite, Sabine, Aija Ilgaza, and Maksims Zolovs. "The probiotic mixture X feeding effect on the growth and development of broiler chicken digestive tract." In Research for Rural Development 2022 : annual 28th international scientific conference proceedings. Latvia University of Life Sciences and Technologies, 2022. http://dx.doi.org/10.22616/rrd.28.2022.019.
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The issue of antibiotic resistance has become more pressing in the last decades. Therefore, substitutes for antibiotics are being sought. The aim of our study was to evaluate the effect of the mixture x of lactic acid bacteria on development of the broiler chicken digestive tract and the growth. The study was organised in three trials. In each trial, 260 one day old Ross 308 broiler chicks (males and females) were obtained from a commercial hatchery. They were randomly divided in two groups – the control group and the probiotic group. The dietary treatment was basal diet for the control group and basal diet + the mixture X of lactic acid bacteria 4 g 10 kg-1 for the probiotic group. Broilers were raised till day 35. All broilers were weighted on the day 1, 7, 14, 21, 28, 35 and 10 birds per treatment were randomly selected and killed by cervical dislocation. The gastrointestinal tract was excised (proventriculus, gizzard, intestines) and weighed with content. Overall, this study achieved significant results of the body weight results in the probiotic and the control groups, 2,835.7g ±161.74 and 2,828.02±115.64, respectively. The body weight of chickens and their gastrointestinal tract parts (proventriculus, gizzard, intestines) did not differ between the probiotic and control groups (p > 0.05).
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Safiullin, R. T., and S. К. Shibitov. "EFFECTIVENESS OF JOINT ADMINISTRATION OF AN ANTICOCCIDIAL DRUG AND A BIOGENIC STIMULANT AGAINST SPONTANEOUS COCCIDIOSIS OF BROILERS IN A FARM SCALE TRIAL." In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. VNIIP – FSC VIEV, 2024. http://dx.doi.org/10.31016/978-5-6050437-8-2.2024.25.357-362.
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The research conducted in our country and abroad has proven that any poultry farm that practices poultry floor management is affected by parasitic diseases, especially eimeriosis. The purpose of this study was to test the effectiveness of joint administration of the anticoccidial drug Diclazuril and the biogenic stimulant ASD against spontaneous coccidiosis in broiler chickens under production conditions. The effectiveness of joint administration of Diclazuril was tested on 1,739 floor management chickens aged 9 to 38 days, at a dose of 2 mL per 1 L of drinking water for 48 hours according to the following scheme: on day of age 9–10; 16–17 and 24–25, and the biogenic stimulant ASD in a dose of 20 mL per 1 L of drinking water for 72 hours according to the scheme: on day of age 9–11; 15–17 and 23–25. The control chickens were given the recommended dose of Amprolium with water. The prevalence and intensity of Coccidia infection, as well as the intense-effectiveness of joint administration were determined based on results of coproscopic examinations of 30 litter samples from each group. The joint administration effect on the weight gain of the broilers was studied on 60 chickens that were individually tagged and weighed at 9 and 38 days of age. The farm scale trial results showed that the intense-effectiveness of the joint administration of Diclazuril and the biogenic stimulant ASD against spontaneous coccidiosis in the broiler chickens was 93.5%, and this had a positive effect on the productivity of the broilers that had their average daily weight gained by 11.5% compared to the control group.
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Al Khatib, Jehad Aljabar Hassan, Larisa Caisin, and Ludmila Bivol. "Particularități tehnologice de creștere a puilor de carne." In Scientific and practical conference with international participation: "Management of the genetic fund of animals – problems, solutions, outlooks". Scientific Practical Institute of Biotechnologies in Animal Husbandry and Veterinary Medicine, 2023. http://dx.doi.org/10.61562/mgfa2023.01.
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Poultry is a strategic branch of the animal husbandry sector with great possibilities for recovery in a short period of time. Feeding is responsible to the greatest extent for the growth and development of poultries, maintaining their health and achieving the purpose for which they are exploited, namely the achievement of meat production. A balanced diet provides essential nutrients for the development, growth and optimal func-tioning of the avian body. The studies were carried out at the company "Sum Agro Service", on hybrid broilers, raised in batteries ensuring microclimate conditions and with the feeding system according to the breeding guide. Ross 308 cross broiler chickens were used for the experiment. It was es-tablished that the growth of ROSS 308 broiler chicken hybrids raised according to the in-tensive system in accordance with the recommendations and the principles of the breeding guide for meat production is of zootechnical interest and depends on the genetic potential, which it was achieved only under the conditions of proper nutrition and knowledge of the particularities of growth.
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Kosolapov, Vladimir, Zinaida Zverkova, Halyaf Ishmuratov, Bella Osipyan, and Larisa Korovina. "Seeds of spring brassica campestris in the diets of chickens-broilers." In Multifunctional adaptive fodder production. Federal Williams Research Center of Forage Production and Agroecology, 2021. http://dx.doi.org/10.33814/mak-2021-25-73-153-157.
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In order to save soybean meal, sunflower oil and reduce the cost of rations, new sources of raw materials can be used. In modern conditions, attention is drawn to the brassica rapa campestris, the seeds of which can be used as a fat and protein supplement. Experiments were carried out to determine the optimal rate for the introduction of seeds of spring rape variety Nadezhda into compound feed for growing broiler chickens. It has been established that this variety belongs to canola varieties and can be included up to 7% (by weight) in the composition of mixed fodders, does not have a negative effect on the state of the body and the growth rate of broiler chickens. The introduction of seeds of spring rape to 7% in the composition of feed for broiler chickens reduces the use of soybean meal to 4.7% and sunflower oil to 2.3% (relative). The efficiency of conversion to products by group was 61.93 % in the control group and 62.18% to 63.62% in the experimental group, respectively.
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Dosković, Vladimir, Snežana Bogosavljević-Bošković, Zdenka Škrbić, et al. "EFFECT OF PROTEASE ADDED IN FOOD AND SEX ON CHICKEN MEAT CLASESS." In 1st International Symposium on Biotechnology. University of Kragujevac, Faculty of Agronomy, 2023. http://dx.doi.org/10.46793/sbt28.223d.
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The effects of feeding low dietary crude protein with supplemental protease and sex on the weight and percent yields of individual meat classes in broiler chickens of hybrid Cobb 500 were investigated. A total of 300 day-old broiler chicks were fed with one of the following three experimental diets: control group (C), the experimental group I (E-I) contained 4% less crude protein than the control (C) and were supplemented with protease (Ronozyme Pro Act) at a concentration of 200mg/kg feed and the experimental group II (E-II) contained 6% less crude protein and were supplemented with protease (Ronozyme Pro Act) at a concentration of 300mg/kg feed. Supplementation of protease to diets had no significant effects on weights of individual meat classes (P>0.05), as well as the percentage of meat classes, and the only differences were manifested between E-I and E-II (P<0.05, female broilers from the E-I group were had a higher percentage of class I meat and a lower percentage of class III meat compared to females from the E-II group). The effect of sex was manifested in the weights of all meat classes and the percentage of class I meat and class III meat (P<0.05).
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Kapitonova, E. A. "ANALYSIS OF MEAT QUALITIES OF BROILERS IN MATHEMATICAL MODELING OF EXPERIENCE." In "International Scientific and Practical Conference" THEORY AND PRACTICE OF VETERINARY PHARMACY, ECOLOGY AND TOXICOLOGY IN AIC ", dedicated to the centenary of the Department of Pharmacology and Toxicology, SPbSUVM. FSBEI HE St. Petersburg SUVM, 2021. http://dx.doi.org/10.52419/3006-2021-2-113-115.
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The development of new mycotoxin adsorbents is an urgent problem of high practical significance. The use of mycotoxin adsorbents of a new generation in broiler poultry farming, allows to increase the yield of carcasses and the quality of meat of broiler chickens. In the laboratory, we have identified the comparative effectiveness of the adsorbents "MeKaSorb" and "Belasorb". The results obtained made it possible to test the adsorbents in production conditions.
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E.P., Dolgov, Abramov A.A., Vasiliadi O.I., Vlasenko A.A., and Semenenko K.A. "STUDYING THE INTESTINAL MORPHOLOGICAL PICTURE OF BROILER CHICKEN IN THERAPY OF MYCOTOXICOSIS." In "INNOVATIVE TECHNOLOGIES IN SCIENCE AND EDUCATION". ДГТУ-Принт, 2021. http://dx.doi.org/10.23947/itno.2021.104-107.
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The article provides data on the study of the effect of a combination of mycotoxins on the body of broilers (T-2 toxin at – a concentration of 0.095 mg/kg and aflatoxin B1 – 0.019 mg/kg) and the results of toxicosis therapy with the drug fibralin consisting of plant fibers of beet pulp, phospholipids of rapeseed lecithin and sodium thiosulfate. Structural changes in the intestines of broilers during feed mycotoxicosis are described. The use of the anti-toxic drug fibralin in poultry leads to a weakening of the effect of xenobiotics, which was confirmed by an increase in the safety of the livestock and weight gain of chickens, a decrease in the clinical manifestations of intoxication, as well as positive changes in the structure of the bird's intestines during histological examination.
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Nida, Ihsan Zain, Aji Praba Baskara, Bambang Ariyadi, Nanung Danar Dono, and Zuprizal Zuprizal. "Effect of Cinnamon Extract on Energy and Protein Utilization Efficiency of Broilers Chickens." In 6th International Seminar of Animal Nutrition and Feed Science (ISANFS 2021). Atlantis Press, 2022. http://dx.doi.org/10.2991/absr.k.220401.006.
Full textReports on the topic "Broilers (Chickens)"
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Cahaner, Avigdor, Susan J. Lamont, E. Dan Heller, and Jossi Hillel. Molecular Genetic Dissection of Complex Immunocompetence Traits in Broilers. United States Department of Agriculture, 2003. http://dx.doi.org/10.32747/2003.7586461.bard.
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Objectives: (1) Evaluate Immunocompetence-OTL-containing Chromosomal Regions (ICRs), marked by microsatellites or candidate genes, for magnitude of direct effect and for contribution to relationships among multiple immunocompetence, disease-resistance, and growth traits, in order to estimate epistatic and pleiotropic effects and to predict the potential breeding applications of such markers. (2) Evaluate the interaction of the ICRs with genetic backgrounds from multiple sources and of multiple levels of genetic variation, in order to predict the general applicability of molecular genetic markers across widely varied populations. Background: Diseases cause substantial economic losses to animal producers. Emerging pathogens, vaccine failures and intense management systems increase the impact of diseases on animal production. Moreover, zoonotic pathogens are a threat to human food safety when microbiological contamination of animal products occurs. Consumers are increasingly concerned about drug residues and antibiotic- resistant pathogens derived from animal products. The project used contemporary scientific technologies to investigate the genetics of chicken resistance to infectious disease. Genetic enhancement of the innate resistance of chicken populations provides a sustainable and ecologically sound approach to reduce microbial loads in agricultural populations. In turn, animals will be produced more efficiently with less need for drug treatment and will pose less of a potential food-safety hazard. Major achievements, conclusions and implications:. The PI and co-PIs had developed a refined research plan, aiming at the original but more focused objectives, that could be well-accomplished with the reduced awarded support. The successful conduct of that research over the past four years has yielded substantial new information about the genes and genetic markers that are associated with response to two important poultry pathogens, Salmonella enteritidis (SE) and Escherichia coli (EC), about variation of immunocompetence genes in poultry, about relationships of traits of immune response and production, and about interaction of genes with environment and with other genes and genetic background. The current BARD work has generated a base of knowledge and expertise regarding the genetic variation underlying the traits of immunocompetence and disease resistance. In addition, unique genetic resource populations of chickens have been established in the course of the current project, and they are essential for continued projects. The US laboratory has made considerable progress in studies of the genetics of resistance to SE. Microsatellite-marked chromosomal regions and several specific genes were linked to SE vaccine response or bacterial burden and the important phenomenon of gene interaction was identified in this system. In total, these studies demonstrate the role of genetics in SE response, the utility of the existing resource population, and the expertise of the research group in conducting such experiments. The Israeli laboratories had showed that the lines developed by selection for high or low level of antibody (Ab) response to EC differ similarly in Ab response to several other viral and bacterial pathogens, indicating the existence of a genetic control of general capacity of Ab response in young broilers. It was also found that the 10w-Ab line has developed, possibly via compensatory "natural" selection, higher cellular immune response. At the DNA levels, markers supposedly linked to immune response were identified, as well as SNP in the MHC, a candidate gene responsible for genetic differences in immunocompetence of chickens.
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Wideman, Jr., Robert F., Nicholas B. Anthony, Avigdor Cahaner, Alan Shlosberg, Michel Bellaiche, and William B. Roush. Integrated Approach to Evaluating Inherited Predictors of Resistance to Pulmonary Hypertension Syndrome (Ascites) in Fast Growing Broiler Chickens. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7575287.bard.
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Background PHS (pulmonary hypertension syndrome, ascites syndrome) is a serious cause of loss in the broiler industry, and is a prime example of an undesirable side effect of successful genetic development that may be deleteriously manifested by factors in the environment of growing broilers. Basically, continuous and pinpointed selection for rapid growth in broilers has led to higher oxygen demand and consequently to more frequent manifestation of an inherent potential cardiopulmonary incapability to sufficiently oxygenate the arterial blood. The multifaceted causes and modifiers of PHS make research into finding solutions to the syndrome a complex and multi threaded challenge. This research used several directions to better understand the development of PHS and to probe possible means of achieving a goal of monitoring and increasing resistance to the syndrome. Research Objectives (1) To evaluate the growth dynamics of individuals within breeding stocks and their correlation with individual susceptibility or resistance to PHS; (2) To compile data on diagnostic indices found in this work to be predictive for PHS, during exposure to experimental protocols known to trigger PHS; (3) To conduct detailed physiological evaluations of cardiopulmonary function in broilers; (4) To compile data on growth dynamics and other diagnostic indices in existing lines selected for susceptibility or resistance to PHS; (5) To integrate growth dynamics and other diagnostic data within appropriate statistical procedures to provide geneticists with predictive indices that characterize resistance or susceptibility to PHS. Revisions In the first year, the US team acquired the costly Peckode weigh platform / individual bird I.D. system that was to provide the continuous (several times each day), automated weighing of birds, for a comprehensive monitoring of growth dynamics. However, data generated were found to be inaccurate and irreproducible, so making its use implausible. Henceforth, weighing was manual, this highly labor intensive work precluding some of the original objectives of using such a strategy of growth dynamics in selection procedures involving thousands of birds. Major conclusions, solutions, achievements 1. Healthy broilers were found to have greater oscillations in growth velocity and acceleration than PHS susceptible birds. This proved the scientific validity of our original hypothesis that such differences occur. 2. Growth rate in the first week is higher in PHS-susceptible than in PHS-resistant chicks. Artificial neural network accurately distinguished differences between the two groups based on growth patterns in this period. 3. In the US, the unilateral pulmonary occlusion technique was used in collaboration with a major broiler breeding company to create a commercial broiler line that is highly resistant to PHS induced by fast growth and low ambient temperatures. 4. In Israel, lines were obtained by genetic selection on PHS mortality after cold exposure in a dam-line population comprising of 85 sire families. The wide range of PHS incidence per family (0-50%), high heritability (about 0.6), and the results in cold challenged progeny, suggested a highly effective and relatively easy means for selection for PHS resistance 5. The best minimally-invasive diagnostic indices for prediction of PHS resistance were found to be oximetry, hematocrit values, heart rate and electrocardiographic (ECG) lead II waves. Some differences in results were found between the US and Israeli teams, probably reflecting genetic differences in the broiler strains used in the two countries. For instance the US team found the S wave amplitude to predict PHS susceptibility well, whereas the Israeli team found the P wave amplitude to be a better valid predictor. 6. Comprehensive physiological studies further increased knowledge on the development of PHS cardiopulmonary characteristics of pre-ascitic birds, pulmonary arterial wedge pressures, hypotension/kidney response, pulmonary hemodynamic responses to vasoactive mediators were all examined in depth. Implications, scientific and agricultural Substantial progress has been made in understanding the genetic and environmental factors involved in PHS, and their interaction. The two teams each successfully developed different selection programs, by surgical means and by divergent selection under cold challenge. Monitoring of the progress and success of the programs was done be using the in-depth estimations that this research engendered on the reliability and value of non-invasive predictive parameters. These findings helped corroborate the validity of practical means to improve PHT resistance by research-based programs of selection.
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Yahav, Shlomo, John Brake, and Noam Meiri. Development of Strategic Pre-Natal Cycling Thermal Treatments to Improve Livability and Productivity of Heavy Broilers. United States Department of Agriculture, 2013. http://dx.doi.org/10.32747/2013.7593395.bard.
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The necessity to improve broiler thermotolerance and live performance led to the following hypothesis: Appropriate comprehensive incubation treatments that include significant temperature management changes will promote angiogenesis and will improve acquisition of thermotolerance and carcass quality of heavy broilers through epigenetic adaptation. It was based on the following questions: 1. Can TM during embryogenesis of broilers induce a longer-lasting thermoregulatory memory (up to marketing age of 10 wk) that will improve acquisition of thermotolerance as well as increased breast meat yield in heavy broilers? 2. The improved sensible heat loss (SHL) suggests an improved peripheral vasodilation process. Does elevated temperature during incubation affect vasculogenesis and angiogenesis processes in the chick embryo? Will such create subsequent advantages for heavy broilers coping with adverse hot conditions? 3. What are the changes that occur in the PO/AH that induce the changes in the threshold response for heat production/heat loss based on the concept of epigenetic temperature adaptation? The original objectives of this study were as follow: a. to assess the improvement of thermotolerance efficiency and carcass quality of heavy broilers (~4 kg); b. toimproveperipheral vascularization and angiogenesis that improve sensible heat loss (SHL); c. to study the changes in the PO/AH thermoregulatory response for heat production/losscaused by modulating incubation temperature. To reach the goals: a. the effect of TM on performance and thermotolerance of broilers reared to 10 wk of age was studied. b. the effect of preincubation heating with an elevated temperature during the 1ˢᵗ 3 to 5 d of incubation in the presence of modified fresh air flow coupled with changes in turning frequency was elucidated; c.the effect of elevated temperature on vasculogenesis and angiogenesis was determined using in ovo and whole embryo chick culture as well as HIF-1α VEGF-α2 VEGF-R, FGF-2, and Gelatinase A (MMP2) gene expression. The effects on peripheral blood system of post-hatch chicks was determined with an infrared thermal imaging technique; c. the expression of BDNF was determined during the development of the thermal control set-point in the preoptic anterior hypothalamus (PO/AH). Background to the topic: Rapid growth rate has presented broiler chickens with seriousdifficulties when called upon to efficiently thermoregulate in hot environmental conditions. Being homeotherms, birds are able to maintain their body temperature (Tb) within a narrow range. An increase in Tb above the regulated range, as a result of exposure to environmental conditions and/or excessive metabolic heat production that often characterize broiler chickens, may lead to a potentially lethal cascade of irreversible thermoregulatory events. Exposure to temperature fluctuations during the perinatal period has been shown to lead to epigenetic temperature adaptation. The mechanism for this adaptation was based on the assumption that environmental factors, especially ambient temperature, have a strong influence on the determination of the “set-point” for physiological control systems during “critical developmental phases.” Recently, Piestunet al. (2008) demonstrated for the first time that TM (an elevated incubation temperature of 39.5°C for 12 h/d from E7 to E16) during the development/maturation of the hypothalamic-hypophyseal-thyroid axis (thermoregulation) and the hypothalamic-hypophyseal-adrenal axis (stress) significantly improved the thermotolerance and performance of broilers at 35 d of age. These phenomena raised two questions that were addressed in this project: 1. was it possible to detect changes leading to the determination of the “set point”; 2. Did TM have a similar long lasting effect (up to 70 d of age)? 3. Did other TM combinations (pre-heating and heating during the 1ˢᵗ 3 to 5 d of incubation) coupled with changes in turning frequency have any performance effect? The improved thermotolerance resulted mainly from an efficient capacity to reduce heat production and the level of stress that coincided with an increase in SHL (Piestunet al., 2008; 2009). The increase in SHL (Piestunet al., 2009) suggested an additional positive effect of TM on vasculogenesis and angiogensis. 4. In order to sustain or even improve broiler performance, TM during the period of the chorioallantoic membrane development was thought to increase vasculogenesis and angiogenesis providing better vasodilatation and by that SHL post-hatch.
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Yahav, Shlomo, John Brake, and Orna Halevy. Pre-natal Epigenetic Adaptation to Improve Thermotolerance Acquisition and Performance of Fast-growing Meat-type Chickens. United States Department of Agriculture, 2009. http://dx.doi.org/10.32747/2009.7592120.bard.
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: The necessity to improve broiler thermotolerance and performance led to the following hypothesis: (a) thethermoregulatory-response threshold for heat production can be altered by thermal manipulation (TM) during incubation so as to improve the acquisition of thermotolerance in the post-hatch broiler;and (b) TM during embryogenesis will improve myoblast proliferation during the embryonic and post-hatch periods with subsequent enhanced muscle growth and meat production. The original objectives of this study were as follow: 1. to assess the timing, temperature, duration, and turning frequency required for optimal TM during embryogenesis; 2. to evaluate the effect of TM during embryogenesis on thermoregulation (heat production and heat dissipation) during four phases: (1) embryogenesis, (2) at hatch, (3) during growth, and (4) during heat challenge near marketing age; 3. to investigate the stimulatory effect of thermotolerance on hormones that regulate thermogenesis and stress (T₄, T₃, corticosterone, glucagon); 4. to determine the effect of TM on performance (BW gain, feed intake, feed efficiency, carcass yield, breast muscle yield) of broiler chickens; and 5. to study the effect of TM during embryogenesis on skeletal muscle growth, including myoblast proliferation and fiber development, in the embryo and post-hatch chicks.This study has achieved all the original objectives. Only the plasma glucagon concentration (objective 3) was not measured as a result of technical obstacles. Background to the topic: Rapid growth rate has presented broiler chickens with seriousdifficulties when called upon to efficiently thermoregulate in hot environmental conditions. Being homeotherms, birds are able to maintain their body temperature (Tb) within a narrow range. An increase in Tb above the regulated range, as a result of exposure to environmental conditions and/or excessive metabolic heat production that often characterize broiler chickens, may lead to a potentially lethal cascade of irreversible thermoregulatory events. Exposure to temperature fluctuations during the perinatal period has been shown to lead to epigenetic temperature adaptation. The mechanism for this adaptation was based on the assumption that environmental factors, especially ambient temperature, have a strong influence on the determination of the “set-point” for physiological control systems during “critical developmental phases.” In order to sustain or even improve broiler performance, TM during the period of embryogenesis when satellite cell population normally expand should increase absolute pectoralis muscle weight in broilers post-hatch. Major conclusions: Intermittent TM (39.5°C for 12 h/day) during embryogenesis when the thyroid and adrenal axis was developing and maturing (E7 to E16 inclusive) had a long lasting thermoregulatory effect that improved thermotolerance of broiler chickens exposed to acute thermal stress at market age by lowering their functional Tb set point, thus lowering metabolic rate at hatch, improving sensible heat loss, and significantly decreasing the level of stress. Increased machine ventilation rate was required during TM so as to supply the oxygen required for the periods of increased embryonic development. Enhancing embryonic development was found to be accomplished by a combination of pre-incubation heating of embryos for 12 h at 30°C, followed by increasing incubation temperature to 38°C during the first 3 days of incubation. It was further facilitated by increasing turning frequency of the eggs to 48 or 96 times daily. TM during critical phases of muscle development in the late-term chick embryo (E16 to E18) for 3 or 6 hours (39.5°C) had an immediate stimulatory effect on myoblast proliferation that lasted for up to two weeks post-hatch; this was followed by increased hypertrophy at later ages. The various incubation temperatures and TM durations focused on the fine-tuning of muscle development and growth processes during late-term embryogenesis as well as in post-hatch chickens.
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Wong, E. A., and Z. Uni. Modulating intestinal cellular maturation and differentiation in broilers by in ovo feeding. United States-Israel Binational Agricultural Research and Development Fund, 2018. http://dx.doi.org/10.32747/2018.8134161.bard.
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Mortality in a broiler flock will typically range from 4-5% of the population over the course of 6- 7 weeks in the U.S. and 7-8% of the population in Israel. Suboptimal intestinal maturation and functionality are one of the major factors that contribute to early age mortality and hinder flock body weight uniformity. The development of absorptive and secretory functions is orchestrated by differentiation of cells that arise from stem cells. Supplying compounds by in ovo feeding (IOF) during late embryogenesis provides nutrients that may change the dynamics of stem cell differentiation. We hypothesize that the introduction of specific nutrients or probiotics to the late embryonic chick via IOF will result in an acceleration of the maturation of the small intestine as measured by villus/crypt morphology and the number and distribution of absorptive and secretory cells. A chick that can absorb nutrients more efficiently by increasing the number of cells expressing nutrient transporters and resist enteric pathogens by increasing the number of cells expressing mucin and host defense peptides will be healthier at hatch. This chick may have less need for antibiotics and may show reduced early mortality. The objectives of this proposal are to: 1) develop a model for the development of putative stem cells and absorptive/secretory cells in the small intestine of the late embryonic and early post hatch broiler. 2) determine the ability of IOF of nutrients to modulate the population of differentiated cells in the intestine. 3) determine the ability of IOF of probiotics to modulate the population of differentiated cells in the intestine. 4) reduce early mortality and increase body weight uniformity by IOF of selected nutrients or probiotics. This proposal combines the IOF expertise of Zehava Uni (Hebrew University) with the RNAscope in situ hybridization technique of Eric Wong (Virginia Tech). Previous studies using quantitative PCR to examine expression of genes in the intestine were unable to identify specific cells expressing these genes. RNAscope allows the ability to identify putative stem, absorptive and secretory cells in the small intestine. Thus, we will be able to investigate the effect of IOF on the presence of intestinal absorptive and secretory cells at the cellular level. Understanding the mechanisms for intestinal development and function are key to maintaining peak growth and health of chickens and thus would be of great economic benefit to the poultry industry.
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Leach, Roland M., Mark Pines, Carol V. Gay, and Shmuel Hurwitz. In vivo and in vitro Chondrocyte Metabolism in Relationship to the Developemnt of Tibial Dyschondroplasia in Broiler Chickens. United States Department of Agriculture, 1993. http://dx.doi.org/10.32747/1993.7568090.bard.
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Skeletal deformities are a significant financial and welfare problem for the world poultry industry. Tibial dyschondroplasia (TD) is the most prevalent skeletal abnormality found in young broilers, turkeys and ducks. Tibial dyschondroplasia results from a perturbation of the sequence of events in the epiphyseal growth plate, the tissue responsible for longitudinal bone growth. The purpose of this investigation was to test the hypothesis that TD was the result of a failure of growth plate chondrocytes to differentiate and express the chemotactic molecules required for cartilage vascularization. In this investigation in situ hybridization and immunocytochemical techniques were used to study chondrocyte gene products associated with cartilage maturation and vascularization such as osteopontin, osteonectin, type X collagen, and alkaline phosphatase. All markers were present in the growth plate tissue anter or to the TD lesion but were greatly diminished in the TD lesion. Thus, rather than not acquiring the markers for hypertrophy, it appears that the growth plate chondrocytes reach a certain stage of hypertrophy and then de-differentiate into cells which resemble chondrocytes in the prehypertrophic zone. Similar patterns were observed in all TD tissues examined whether the lesions were spontaneous or induced by dietary treatments or genetic selection. The decrease in gene expression can at least be partially explained by the fact that many of the dysplastic chondrocytes show classic signs of apoptosis. These results provide an explanation for the observation that a variety of genes show reduced expression in the TD lesion when examined by in situ hybridization. This would suggest that future research should focus on the earliest detectable stages in the development of TD and examine endocrine and autocrine factors which cause chondrocytes to de-differentiate and undergo premature apoptosis.
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Schat, Karel Antoni, Irit Davidson, and Dan Heller. Chicken infectious anemia virus: immunosuppression, transmission and impact on other diseases. United States Department of Agriculture, 2008. http://dx.doi.org/10.32747/2008.7695591.bard.
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1. Original Objectives. The original broad objectives of the grant were to determine A) the impact of CAV on the generation of cytotoxic T lymphocytes (CTL) to reticuloendotheliosis virus (REV) (CU), B). the interactions between chicken anemia virus (CAV) and Marek’s disease virus (MDV) with an emphasis on horizontal spread of CAV through feathers (KVI), and C) the impact of CAV infection on Salmonella typhimurium (STM) (HUJI). During the third year and the one year no cost extension the CU group included some work on the development of an antigen-antibody complex vaccine for CAV, which was partially funded by the US Poultry and Egg Association. 2. Background to the topic. CAV is a major pathogen causing clinical disease if maternal antibody-free chickens are infected vertically or horizontally between 1 and 14 days of age. Infection after 3 weeks of age when maternal antibodies are not longer present can cause severe subclinical immunosuppression affecting CTL and cytokine expression. The subclinical immunosuppression can aggravate many diseases including Marek’s disease (MD) and several bacterial infections. 3. Major conclusions and achievements. The overall project contributed in the following ways to the knowledge about CAV infection in poultry. As expected CAV infections occur frequently in Israel causing problems to the industry. To control subclinical infections vaccination may be needed and our work indicates that the development of an antigen-antibody complex vaccine is feasible. It was previously known that CAV can spread vertically and horizontally, but the exact routes of the latter had not been confirmed. Our results clearly show that CAV can be shed into the environment through feathers. A potential interaction between CAV and MD virus (MDV) in the feathers was noted which may interfere with MDV replication. It was also learned that inoculation of 7-day-old embryos causes growth retardation and lesions. The potential of CAV to cause immunosuppression was further examined using CTL responses to REV. CTL were obtained from chickens between 36 and 44 days of age with REV and CAV given at different time points. In contrast to our earlier studies, in these experiments we were unable to detect a direct impact of CAV on REV-specific CTL, perhaps because the CTL were obtained from older birds. Inoculation of CAV at one day of age decreased the IgG antibody responses to inactivated STM administered at 10 days of age. 4. Scientific and Agricultural Implications The impact of the research was especially important for the poultry industry in Israel. The producers have been educated on the importance of the disease through the many presentations. It is now well known to the stakeholders that CAV can aggravate other diseases, decrease productivity and profitability. As a consequence they monitor the antibody status of the breeders so that the maternal antibody status of the broilers is known. Also vaccination of breeder flock that remain antibody negative may become feasible further reducing the negative impact of CAV infection. Vaccination may become more important because improved biosecurity of the breeder flocks to prevent avian influenza and Salmonella may delay the onset of seroconversion for CAV by natural exposure resulting in CAV susceptible broilers lacking maternal antibodies. Scientifically, the research added important information on the horizontal spread of CAV through feathers, the interactions with Salmonella typhimurium and the demonstration that antigen-antibody complex vaccines may provide protective immunity.
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Yahav, Shlomo, John McMurtry, and Isaac Plavnik. Thermotolerance Acquisition in Broiler Chickens by Temperature Conditioning Early in Life. United States Department of Agriculture, 1998. http://dx.doi.org/10.32747/1998.7580676.bard.
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The research on thermotolerance acquisition in broiler chickens by temperature conditioning early in life was focused on the following objectives: a. To determine the optimal timing and temperature for inducing the thermotolerance, conditioning processes and to define its duration during the first week of life in the broiler chick. b. To investigate the response of skeletal muscle tissue and the gastrointestinal tract to thermal conditioning. This objective was added during the research, to understand the mechanisms related to compensatory growth. c. To evaluate the effect of early thermo conditioning on thermoregulation (heat production and heat dissipation) during 3 phases: (1) conditioning, (2) compensatory growth, (3) heat challenge. d. To investigate how induction of improved thermotolerance impacts on metabolic fuel and the hormones regulating growth and metabolism. Recent decades have seen significant development in the genetic selection of the meat-type fowl (i.e., broiler chickens); leading to rapid growth and increased feed efficiency, providing the poultry industry with heavy chickens in relatively short growth periods. Such development necessitates parallel increases in the size of visceral systems such as the cardiovascular and the respiratory ones. However, inferior development of such major systems has led to a relatively low capability to balance energy expenditure under extreme conditions. Thus, acute exposure of chickens to extreme conditions (i.e., heat spells) has resulted in major economic losses. Birds are homeotherms, and as such, they are able to maintain their body temperature within a narrow range. To sustain thermal tolerance and avoid the deleterious consequences of thermal stresses, a direct response is elicited: the rapid thermal shock response - thermal conditioning. This technique of temperature conditioning takes advantage of the immaturity of the temperature regulation mechanism in young chicks during their first week of life. Development of this mechanism involves sympathetic neural activity, integration of thermal infom1ation in the hypothalamus, and buildup of the body-to-brain temperature difference, so that the potential for thermotolerance can be incorporated into the developing thermoregulation mechanisms. Thermal conditioning is a unique management tool, which most likely involves hypothalamic them1oregulatory threshold changes that enable chickens, within certain limits, to cope with acute exposure to unexpected hot spells. Short-tem1 exposure to heat stress during the first week of life (37.5+1°C; 70-80% rh; for 24 h at 3 days of age) resulted in growth retardation followed immediately by compensatory growth" which resulted in complete compensation for the loss of weight gain, so that the conditioned chickens achieved higher body weight than that of the controls at 42 days of age. The compensatory growth was partially explained by its dramatic positive effect on the proliferation of muscle satellite cells which are necessary for further muscle hypertrophy. By its significant effect of the morphology and functioning of the gastrointestinal tract during and after using thermal conditioning. The significant effect of thermal conditioning on the chicken thermoregulation was found to be associated with a reduction in heat production and evaporative heat loss, and with an increase in sensible heat loss. It was further accompanied by changes in hormones regulating growth and metabolism These physiological responses may result from possible alterations in PO/AH gene expression patterns (14-3-3e), suggesting a more efficient mechanism to cope with heat stress. Understanding the physiological mechanisms behind thermal conditioning step us forward to elucidate the molecular mechanism behind the PO/AH response, and response of other major organs. The thermal conditioning technique is used now in many countries including Israel, South Korea, Australia, France" Ecuador, China and some places in the USA. The improvement in growth perfom1ance (50-190 g/chicken) and thermotolerance as a result of postnatal thermal conditioning, may initiate a dramatic improvement in the economy of broiler's production.
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Uni, Zehava, and Peter Ferket. Enhancement of development of broilers and poults by in ovo feeding. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7695878.bard.
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The specific objectives of this research were the study of the physical and nutritional properties of the In Ovo Feeding (IOF) solution (i.e. theosmostic properties and the carbohydrate: protein ratio composition). Then, using the optimal solution for determining its effect on hatchability, early nutritional status and intestinal development of broilers and turkey during the last quarter of incubation through to 7 days post-hatch (i.e. pre-post hatch period) by using molecular, biochemical and histological tools. The objective for the last research phase was the determination of the effect of in ovo feeding on growth performance and economically valuable production traits of broiler and turkey flocks reared under practical commercial conditions. The few days before- and- after hatch is a critical period for the development and survival of commercial broilers and turkeys. During this period chicks make the metabolic and physiological transition from egg nutriture (i.e. yolk) to exogenous feed. Late-term embryos and hatchlings may suffer a low glycogen status, especially when oxygen availability to the embryo is limited by low egg conductance or poor incubator ventilation. Much of the glycogen reserve in the late-term chicken embryo is utilized for hatching. Subsequently, the chick must rebuild that glycogen reserve by gluconeogenesis from body protein (mostly from the breast muscle) to support post-hatch thermoregulation and survival until the chicks are able to consume and utilize dietary nutrients. Immediately post-hatch, the chick draws from its limited body reserves and undergoes rapid physical and functional development of the gastrointestinal tract (GIT) in order to digest feed and assimilate nutrients. Because the intestine is the nutrient primary supply organ, the sooner it achieves this functional capacity, the sooner the young bird can utilize dietary nutrients and efficiently grow at its genetic potential and resist infectious and metabolic disease. Feeding the embryo when they consume the amniotic fluid (IOF idea and method) showed accelerated enteric development and elevated capacity to digest nutrients. By injecting a feeding solution into the embryonic amnion, the embryo naturally consume supplemental nutrients orally before hatching. This stimulates intestinal development to start earlier as was exhibited by elevated gene expression of several functional genes (brush border enzymes an transporters , elvated surface area, elevated mucin production . Moreover, supplying supplemental nutrients at a critical developmental stage by this in ovo feeding technology improves the hatchling’s nutritional status. In comparison to controls, administration of 1 ml of in ovo feeding solution, containing dextrin, maltose, sucrose and amino acids, into the amnion of the broiler embryo increased dramatically total liver glycogen in broilers and in turkeys in the pre-hatch period. In addition, an elevated relative breast muscle size (% of broiler BW) was observed in IOF chicks to be 6.5% greater at hatch and 7 days post-hatch in comparison to controls. Experiment have shown that IOF broilers and turkeys increased hatchling weights by 3% to 7% (P<0.05) over non injected controls. These responses depend upon the strain, the breeder hen age and in ovo feed composition. The weight advantage observed during the first week after hatch was found to be sustained at least through 35 days of age. Currently, research is done in order to adopt the knowledge for commercial practice.
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Halevy, Orna, Sandra Velleman, and Shlomo Yahav. Early post-hatch thermal stress effects on broiler muscle development and performance. United States Department of Agriculture, 2013. http://dx.doi.org/10.32747/2013.7597933.bard.
Full textAbstract:
In broilers, the immediate post-hatch handling period exposes chicks to cold or hot thermal stress, with potentially harmful consequences to product quantity and quality that could threaten poultry meat marketability as a healthy, low-fat food. This lower performance includes adverse effects on muscle growth and damage to muscle structure (e.g., less protein and more fat deposition). A leading candidate for mediating the effects of thermal stress on muscle growth and development is a unique group of skeletal muscle cells known as adult myoblasts (satellite cells). Satellite cells are multipotential stem cells that can be stimulated to follow other developmental pathways, especially adipogenesis in lieu of muscle formation. They are most active during the first week of age in broilers and have been shown to be sensitive to environmental conditions and nutritional status. The hypothesis of the present study was that immediate post-hatch thermal stress would harm broiler growth and performance. In particular, growth characteristics and gene expression of muscle progenitor cells (i.e., satellite cells) will be affected, leading to increased fat deposition, resulting in long-term changes in muscle structure and a reduction in meat yield. The in vitro studies on cultured satellite cells derived from different muscle, have demonstrated that, anaerobic pectoralis major satellite cells are more predisposed to adipogenic conversion and more sensitive during myogenic proliferation and differentiation than aerobic biceps femoris cells when challenged to both hot and cold thermal stress. These results corroborated the in vivo studies, establishing that chronic heat exposure of broiler chicks at their first two week of life leads to impaired myogenicity of the satellite cells, and increased fat deposition in the muscle. Moreover, chronic exposure of chicks to inaccurate temperature, in particular to heat vs. cold, during their early posthatch periods has long-term effects of BW, absolute muscle growth and muscle morphology and meat quality. The latter is manifested by higher lipid and collagen deposition and may lead to the white striping occurrence. The results of this study emphasize the high sensitivity of muscle progenitor cells in the early posthatch period at a time when they are highly active and therefore the importance of rearing broiler chicks under accurate ambient temperatures. From an agricultural point of view, this research clearly demonstrates the immediate and long-term adverse effects on broiler muscling and fat formation due to chronic exposure to hot stress vs. cold temperatures at early age posthatch. These findings will aid in developing management strategies to improve broiler performance in Israel and the USA. BARD Report - Project4592 Page 2 of 29