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1
Jones, Robert Eric. « Effect of feeding calcium propionate on carcass composition, and productive performance of male broilers ». Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=778.
Texte intégralRésumé :
Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains viii, 69 p. : ill. (some col.) Vita. Includes abstract. Includes bibliographical references (p. 58-62).
2
Massey, Joseph W. « Comparison of broiler breeder production and fertility in a colony cage system with two different floors versus a slat-floor system ». Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2447.
Texte intégralRésumé :
Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains viii, 46 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 29-31).
3
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.
Texte intégralRésumé :
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.
4
Decolongon, Joji. « The influence of slat material, slat coverage and breeder age on broiler breeder reproduction and progeny growth ». Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28978.
Texte intégralRésumé :
This study was conducted to examine the potential of plastic slats as flooring material for maintenance of broiler breeders. Although plastic slats are more expensive than wood slats, plastic slats are more durable and easier to clean.
Wood and plastic slats were tested as full and partial flooring to determine the ideal proportion of slats for broiler breeder floors. Space allotment was 2040 cm²/bird on all floor treatments. . Arbor Acres broiler breeders, one of the more common strains in British Columbia, were raised to 58 weeks of age to monitor the influence of slat material and slat coverage on egg production and progeny growth over one production cycle.
Since the pens were not set up to determine the number of eggs lost through slats, "egg production" values were actually egg recovery values. Over-all egg recovery was significantly higher on partial wood (PWS) and partial plastic slats (PPS) than on either of the full slat treatments. Breeders on full wood slats (FWS) had higher over-all egg production than those on full plastic slats (FPS).
Differences were significant for three biweekly periods, but slats did not influence the over-all incidence of floor eggs and cracked floor eggs. The incidence of
cracked nest eggs was significantly higher in FWS and FPS than in PWS and PPS pens during four lay periods and overall.
The proportion of non-cracked nest eggs, which was taken as an approximation of the proportion of settable eggs, was higher for partial slat pens than full slat pens, and FWS pens had a higher proportion of non-cracked nest eggs than FPS pens.
To monitor fertility and hatchability, eggs were incubated at 37, 42, 46, 50 and 56 weeks of breeder age. Fertility, hatchability of total eggs set and hatchability of fertile eggs was not affected by type of slats.
Progeny from the hatch at 37, 46 and 56 week of breeder age were grown in Petersime battery cages to three weeks of age. The progeny of breeders on FPS had lower first week weight gain than the other progeny groups due to moisture loss when 7 FPS progeny were lost during the second growth trial. Weekly and over-all feed conversion of progeny was not affected by types of slats used by parents.
The 56th week progeny were grown in Petersime battery cages to market age (six weeks). PWS and FPS progeny had higher third week weight gain than PPS progeny. During the sixth week, FWS and PWS progeny had higher weight gain than FPS and PPS progeny. The sixth week feed conversion of FPS
progeny was higher than that of the other three progeny groups. No other differences were seen.
As long as slats were used as partial flooring, there were no differences in egg production on wood or plastic slats. The proportion of "settable" eggs, fertility, and hatchability of eggs of plastic slat breeders were comparable with that of wood slat breeders regardless of slat coverage. There were significant differences in the 3-week growth of 37th, 46th and 56th week progeny and the 6-week growth of 56th week progeny on the different slat types, but the differences were not due to slat treatments. There was no interaction between breeder age and slat material, therefore the influence of slat material on egg production and progeny growth did not vary with breeder age. Although egg recovery and the number of settable eggs were lower for FPS breeders, breeders on plastic slats performed as well as those on wood slats in the present study.Land and Food Systems, Faculty of
Graduate
5
Botlhoko, Tuelo David. « Performance of Clostridium perfringens-challenged broilers inoculated with effective microorganisms ». Pretoria : [s.n.], 2010. http://upetd.up.ac.za/thesis/available/etd-02192010-172630.
Texte intégral
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Jansen, van Rensburg Christine. « The ameliorating effect of oxihumate on aflatoxine in broilers ». Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-05082006-110731.
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MacLean, Janice L. (Janice Leigh). « Genetic and nutritional factors affecting growth, nutrient utilization and body composition of broiler chickens ». Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22395.
Texte intégralRésumé :
Two growth trials were designed to measure the effects of: (1) dietary Virginiamycin (0 or 16.5 mg/kg) and added fat (0 or 4%), and (2) Virginiamycin (0 or 16.5 mg/kg) and dietary lysine levels (low, NRC, high) individually, and in combination on broiler performance. A third trial investigated the relationship of plasma glucose, triglyceride and phospholipid concentrations with degree of fatness/leanness in genetically lean and fat broiler chickens. A combination of supplemental fat and Virginiamycin increased protein and decreased fat content of the dressed carcass. Virginiamycin supplementation overcame the growth depression of a low lysine diet by increasing feed intake. In the low lysine diet, Virginiamycin supplementation reduced abdominal fat deposition in females and increased carcass yield in males. Carcass protein content was increased by feeding the NRC-recommended level of lysine or by Virginiamycin supplementation. (Abstract shortened by UMI.)
8
Newman, R. E. « Modulation of avian metabolism by dietary fatty acids ». Connect to full text, 2000. http://hdl.handle.net/2123/799.
Texte intégralRésumé :
Thesis (Ph. D.)--University of Sydney, 2001.Includes tables. Title from title screen (viewed Apr. 23, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Animal Science, Faculty of Veterinary Science. Degree awarded 2001; thesis submitted 2000. Includes bibliography. Also available in print form.
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Gehring, Curran Kenji. « Improvement of the physical and nutritional quality of pelleted feed ». Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10563.
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Lehman, Regina N. Moran Edwin T. « The effect of gelatin and dietary crude protein level on broilers vaccinated for coccidiosis ». Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Poultry_Science/Thesis/Lehman_Regina_58.pdf.
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Bassler, Arnd W. « Organic broilers in floorless pens on pasture / ». Uppsala : Dept. of Animal Nutrition and Management, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200567.pdf.
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Russell, Katherine Margaret. « Intestinal responses to Clostridium perfringens in broilers ». Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/25514.
Texte intégralRésumé :
Clostridium perfringens is the aetiological agent of Necrotic enteritis (NE); a disease that impacts on the health and welfare of broilers. This disease is a large cost to the industry and presents as lesions in the small intestine hindering productivity. Antibiotics are commonly used to treat NE but as pressure increases to limit their use further information about disease onset and broiler responses to the bacteria and it’s virulence factors during infection is required to implement new preventative measures and treatments. NetB is a secreted toxin from C. perfringens which has an important role in NE onset. Using an in situ intestinal loop model we have been able to characterise: I) temporal broiler responses to NetB positive bacterial culture supernatant (Chapter 2), ii) early host responses to different isolates possessing NetB (virulent) or not (avirulent) in the presence or absence of bacterial cells (Chapter 3) and iii) the responses of two commercial broiler breeds (Chapter 4) four hours post exposure. Samples collected from these experiments have been used for histology, mRNA expression and immunohistology. We have shown differences in mRNA expression in the duodenum of broilers after exposure to C. perfringens cells as well as the culture supernatant from the isolates used after four hours. The presence of bacteria cells resulted in up-regulation of pro-inflammatory cytokine, IFN-γ, mRNA, whereas it resulted in down-regulation of B-LA, mRNA a gene involved in presentation of pathogens to immune cells. IL-6 mRNA expression was also reduced in the presence of virulent isolates. This could indicate a possible evasion strategy for C. perfringens in broilers. Immunohistochemical analysis indicated that slower growing broilers have increased numbers of immune cells (macrophages and γδ T cells) in their duodenum compared with faster growing broilers, although this did not appear to have an effect on mRNA expression levels of pro-inflammatory cytokines, 4h post antigen infusion. Overall we detect greater changes when bacteria are included with culture supernatant and have highlighted possible mechanisms for C. perfringens to avoid the broiler immune system. Induction of NE in the literature requires pre-disposing factors, including co-infection with other intestinal pathogens and dietary manipulation of the host. The final experiment trialled protocols administering a virulent isolate of C. perfringens in-feed and via gavage along with an increased protein source to induce NE (Chapter 5). These models were not considered to be consistent for further investigation of NE in the future.
13
McGruder, Brenna Mariechen. « Effects of individual and combinatorial electrolyte solutions comprised of various carbohydrates, salts, and stimulants injected into broiler hatching eggs on subsequent late term embryogenesis and post hatch performance through tendays of age ». Master's thesis, Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-04042008-113902.
Texte intégral
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Bisschop, Shahn P. R. « The use of a bacterin vaccine in broiler breeders in the control of Ornithobacterium rhinotracheale in commercial broilers ». Diss., University of Pretoria, 2003. http://hdl.handle.net/2263/23545.
Texte intégralRésumé :
Respiratory disease complex is a major cause of mortality and economic losses in the commercial broiler industry. In 1991 a previously unidentified bacterium associated with respiratory disease and cranial cellulitis was isolated from broilers in the then Transvaal Province (van Beek, van Empel, van den Bosch, Storm, Bongers, du Preez, 1994. ). In 1994 the organism was named Ornithobacterium rhinotracheale (Vandamme, Segers, Vancanneyt, van Hove, Mutters, Hommez, Dewhirst, Paster, Kersters, Falsen, Devriese, Bisgaard, Hinz, Mannheim, 1994.). Since then Ornithobacterium rhinotracheale has been isolated worldwide from chickens and turkeys showing respiratory signs and has become well established as contributing to the respiratory disease complex in both species (van Empel, Hafez, 1999). In South Africa respiratory disease and Ornithobacterium rhinotracheale in particular is routinely controlled by the inclusion of antibiotics such as Oxtetracycline into the feed of broilers during rearing. Concerns about antibiotic residues in poultry meat for human consumption as well as evidence that suggests that Ornithobacterium rhinotracheale readily develops resistance to antibiotics (Devriese, Hommez, Vandamme, Kersters, Haesebrouck, 1995), make this strategy unsustainable. It was with a view to reducing producers’ dependence on long term prophylactic antibiotic therapy that this study to determine the safety and efficacy of an OR bacterin vaccine was carried out. Injection of the bacterin into broilers was deemed impractical on a commercial scale, so it was applied to broiler breeder parent stock in order that they could protect their progeny through vertically transmitted immunity developed as a result of vaccination. Breeder flocks were vaccinated intramuscularly at nine and 18 weeks with a monovalent bacterin based on OR serotype A with oil adjuvant. Vaccine safety was evaluated by palpation of vaccination sites and clinical observation of breeders for two weeks after vaccination. The serological response of breeders to vaccination was monitored using an ELISA test for Ornithobacterium rhinotracheale optimised for use under South African conditions. Vaccine efficacy was determined by monitoring of broiler progeny of vaccinated breeders raised under commercial conditions as well as through controlled challenge studies with Ornithobacterium rhinotracheale under laboratory conditions. In order to determine the financial consequences of using the test vaccine, a partial farm budget was drawn up from available broiler data and possible outcomes were modelled using a stochastic model. The vaccine proved to be safe for use in commercial broiler breeders and vaccinated birds developed a good humoral response to vaccination. As a result of cross-contamination of isolators with Ornithobacterium rhinotracheale the results of the challenge studies were inconclusive. No evidence of protection of broiler progeny of vaccinated breeder flocks could be detected through the challenge trials. In the absence of in-feed medication, broilers hatched from vaccinated breeders did, however, performed better under commercial conditions than those hatched from unvaccinated breeder flocks. The partial farm budget showed that broilers raised from OR vaccinated breeder flocks were more profitable than the negative control flocks. The quantitative risk analysis showed that the probability of making a relative profit from broilers as a result of OR vaccination of parent stock was 74%, from the use of in-feed medication in broilers from unvaccinated parents was 70% and from a combination of the interventions was 99%. It can be concluded that the last of these options was most profitable.Dissertation (MSc (Veterinary Sciences))--University of Pretoria, 2003.
Veterinary Tropical Diseases
unrestricted
15
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.
Texte intégralRésumé :
Thesis (MScFoodSc)--Stellenbosch University, 2013.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.
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.
Texte intégralRésumé :
Thesis (Bsc. (Animal production)) --University of Limpopo, 2009.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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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.
Texte intégralRésumé :
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.
Texte intégralRésumé :
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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Darmani-Kuhi, Hassan. « A modelling analysis of growth in poultry ». Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270844.
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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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Gilbert, André. « The value of dietary fats for improving reproductive performance of broiler breeder chickens / ». Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59945.
Texte intégralRésumé :
The effects of dietary fat on the reproductive performance of broiler breeder chickens have been studied. Individually caged broiler breeders were fed diets with or without added fat during 19-wk reproductive period. In Experiment 1, only the females were subjected to dietary treatments: control (no added fat), 3% animal-vegetable fat blend (A-V fat, 3% corn oil (CO)), while the males received a non-added fat diet. In Experiment 2, only the males were fed diets containing 0 or 3% of either A-V fat or CO while the females were provided a non-added-fat diet.In Experiment 1, added dietary fat produced significantly higher fertility and early embryonic livability. In Experiment 2, inclusion of 3% CO in the males' diets significantly increased late embryo livability and total embryo survival resulting in a significantly higher hatchability. There were no differences in semen characteristics among dietary treatments. These data indicate that the contribution of the male is not restricted to the fertilization of eggs but is also related to embryonic livability. The addition of fat significantly affected the fatty acid composition of the phospholipid fraction of the spermatozoa cells.
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McLea, Linda A. « The use of glycerol in diets for broilers ». Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534617.
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Payne, Steven George. « The phosphorus availability of feed phosphates in broilers ». Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/1859.
Texte intégralRésumé :
Thesis (MscAgric (Animal Sciences))--University of Stellenbosch, 2005.Broiler diets are supplemented with feed phosphates to ensure that adequate available phosphorus is provided in the diet to meet the bird’s requirements. These feed phosphates make a considerable contribution to the total available phosphorus in the diet and small differences in their availability may have significant effects on whether the bird’s requirements are met or not. The variation in availability of phosphorus between feed phosphates belonging to different classes and between feed phosphates of the same generic class is well documented.
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Costa, Manuel João Gonçalves da. « "Osteocondrodistrofias em Broilers : Etiologias e Impacto na Produçao" ». Master's thesis, Instituto de Ciências Biomédicas Abel Salazar, 2009. http://hdl.handle.net/10216/23168.
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Howlider, Abdur Rahman. « Rearing temperature and the meat yield of broilers ». Thesis, University of Aberdeen, 1988. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602262.
Texte intégralRésumé :
The objective of this study was to examine the effects of rearing temperature on the meat yield of broilers. Four experiments were conducted. Experiment 1 examined meat yield at different temperatures and on different diets when birds were grown to a fixed age. Experiments 2 and 3 were aimed at the effects of temperature and of the interaction between temperature and stocking density respectively on the meat yield of broilers when killed at a specified liveweight (i.e. allowing the rearing period to vary). Experiment 4 was designed to assess whether depression of growth rate at high temperature affected the meat yield in broilers.
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Costa, Manuel João Gonçalves da. « "Osteocondrodistrofias em Broilers : Etiologias e Impacto na Produçao" ». Dissertação, Instituto de Ciências Biomédicas Abel Salazar, 2009. http://hdl.handle.net/10216/23168.
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Walk, Carrie. « Evaluation of the efficacy of high levels of microbial phytase in broilers ». Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4630.
Texte intégralRésumé :
Thesis (M.S.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 22, 2009) Includes bibliographical references.
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Mandour, Mohamed A. « Selection for wingbone breaking strength in cage-reared broilers / ». The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu148758564557571.
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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.
Texte intégralRésumé :
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.Ph. D.
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Potturi, Lakshmi Prasanna. « Comparison of plate media for isolation of Campylobacter from live broilers and scheduled delivery of broiler flocks to reduce cross-contamination with Campylobacter ». Auburn, Ala., 2006. http://repo.lib.auburn.edu/Send%206-15-07/POTTURI-VENKATA_LAKSHMI-PRAS_2.pdf.
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Sebastian, Sylvester. « The effects of supplemental microbial phytase on nutrient utilization in broiler chickens / ». Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34448.
Texte intégralRésumé :
The influence of microbial phytase on growth performance, availability of macro and trace minerals, apparent ileal digestibility (AID) and apparent "fecal" digestibility (AFD) of amino acids (AA) and CP were investigated. The optimum level of dietary Ca and P for the maximum efficacy of supplemental phytase in broiler chickens was also studied. Phytase supplementation (600 U/kg) to a low P diet increased $(P 0.05)$ on feed efficiency in broiler chickens at 21 d. The efficacy of phytase, particularly in stimulating growth, was higher in male than female chickens. The relative retention of Ca, P, Cu, Zn and N increased by addition of phytase to a low P diet but phytase had no effect $(P >0.05)$ on the retention of Mg, Mn and Fe. Phytase supplementation increased $(P 0.05)$ on plasma Zn, Cu, and Mg. Phytase increased $(P 0.05)$ on mineral proportions in the tibia ash; however, it increased $(P 0.05)$ on AID of any of the AA in male chickens. Addition of phytase did not have any effect $(P > 0.05)$ on AFD of any of the AA in male chickens but increased $(P 0.05)$ on either AID or AFD of CP and AA at 21-d. In summary, phytase supplementation increased the growth performance, availability of P, Ca, Cu, Zn and N, plasma P, and tibia ash and reduced plasma Ca; it also increased the AID and AFD of most of the AA, particularly in female chickens at 28-d. The efficacy of microbial phytase was high when dietary P and Ca levels were low.
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Battula, Vamsidhar. « The effects of low atmosphere stunning and deboning time on broiler breast meat quality ». Master's thesis, Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-10202008-145100.
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Cadwell, Kevin. « Investigations of the gut innate defences of commercial broilers ». Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/3067.
Texte intégralRésumé :
The E.U. ban on the use of anti-microbial growth promoters in poultry feed, introduced to counter global problems of bacterial antibiotic resistance, has increased the risk of enteric disease in commercially reared broiler chickens. Development of strategies to prevent such diseases requires further knowledge and understanding of avian gut defences and particularly the innate immune defences. In collaboration with Aviagen Ltd., the objective of this study was to investigate, through two farm trials, the effects of bacterial exposure on host avian β-defensin (AvBD) expression profiles and gut health of two commercial broiler lines (X and Y). Furthermore, two host defense peptides, avian beta defensin 1 (AvBD1) and 10 (AvBD10) were analysed in vitro for their anti-microbial efficacies. In Trial 1, Lines X and Y, differing in their gut health, were exposed to one of three bacterial challenges on the day of hatch, namely a combination of Bacteroides dorei and Barnesiella viscericola (B/BV), Lactobacillus johnsonii (LJ) or a mixture of the two challenges (B/BV + LJ). At days 4, 7, 14, 21, 28 and 35, birds were scored for gut health using an industry approved system and digesta were sampled and analysed for microbiotae (pyrosequencing). The data revealed that, relative to control and LJ challenged birds, the B/BV challenge was associated with gut health deterioration. Furthermore, relative to Line X, there was a trend for the gut health of Line Y birds to be superior for all challenged groups. Although microbiome analyses did not reveal any clear differences between Lines X and Y, the data did suggest that birds with better gut health outcomes were associated with higher ileal Lactobacillus spp. levels at Day 4 and higher caecal levels of Bacteroides spp. at Day 21. Despite less optimal gut health, Line X is important to the Aviagen Ltd. breeding programme. To understand the roles, if any, of the AvBDs in bird gut health, a second trial was performed in which gut AvBD1 and 10 gene expression were assessed in Line X birds following B/BV challenge. Relative to control birds, the B/BV challenge suppressed gene expression of AvBD1 in the duodenum/jejunum (P < 0.05) and AvBD10 in the duodenum/caecum (P < 0.05) and AvBD1 down-regulation was confirmed at the cellular level by data from an in vitro challenge model (P < 0.001). Interestingly, within the B/BV challenged group, birds with higher AvBD1 expression were associated with better gut health assessments. The AvBD1 gene contains single nucleotide polymorphisms (SNP) within the region encoding region the mature peptide. Three AvBD1 variants were synthesised that were typical to Line X (NYH), Y (SSY) and another commercial Line, Z (NYY), and were assessed, together with AvBD10, for in vitro anti-microbial activities (AMAs) against a variety of gut bacterial isolates. Despite Line X displaying the least optimal gut health, the ‘NYH’ variant exhibited the greatest potency against all bacterial species. The data for AvBD10 revealed that, although bacterial growth was inhibited, this peptide had lower AMA than AvBD1, indicative of additional physiological functions. An in vitro examination of wound healing capacity using a scratch assay was inconclusive. The in vivo data indicated that gut AvBD expression is susceptible to gene down-regulation by bacteria and that this, in turn, may have an adverse outcome on gut health. However, selectively breeding for birds able to maintain high AvBD expression presents a strategy to protect flocks against the threat of endemic gut health problems.
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McWilliams, Lindsay Hale. « PHYSIOLOGICAL IMPACT OF HEMATOCRIT LEVEL DURING STRESS IN BROILERS ». MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-06272008-211216/.
Texte intégralRésumé :
Initial experiments evaluated the impact of hematocrit on a birds ability to adapt to stress and what physiological mechanisms occurred to maintain oxygen carrying capacity (OCC). A final experiment was conducted to obtain proteomic evaluation of protein expression in monocytes of unstressed broilers. In initial experiments, ACTH treatment was applied to hematocrit separated broilers. Experiments evaluated effects of ACTH on broilers with low (19 to 22%, Experiment 1; 18-21%, Experiment 3), high (25 to 28%, Experiment 1; 24 to 27%, Experiment 3) or non-selected hematocrit levels (Experiment 2 and 3). After 4 d of ACTH, all treated birds had significantly increased (P < 0.1) pCO2, HCO3-, and corticosterone levels, indicating as stress raises pCO2, HCO3- must rise to maintain acid base balance. Birds not selected for hematocrit had significant drops in pO2 when given ACTH. Broilers compensate for low OCC through release of red blood cells from storage sites, indicated by decreases in organ hemoglobin and increases in hematocrit and blood hemoglobin when birds are given ACTH. Accelerated red blood cell formation does not appear to occur, because erythropoietin decreases following administration of ACTH to non-selected birds. ACTH induced stress, increased hemoglobin and hematocrit only in birds with low or non-selected hematocrit, suggesting high hematocrit birds prior to stress have an adaptive advantage during stress. Higher hematocrit prior to stress apparently provides ample OCC during stress. Unselected birds appear to require initiation of an inflammatory response to adapt to stress which can be noted by increases in total white blood cell count, monocytes, and heterophils and decreases in lymphocytes. High hematocrit birds appear less susceptible to stress effects by maintaining leukocytes at a constant level, while in non-selected birds lymphocyte percents drop. Proteomics was conducted on avian monocytes to reveal proteins related to immune functions, 3229 proteins were identified, with 46 involved in immune functions of professional antigen presenting cells. This protein data provides a means of comparing monocytes of stressed and unstressed animals in the future. In conclusion, evaluated hematocrit is advantageous in adaptation to stress through maintenance of high OCC, acid base balance and immune cells.
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Amwele, Hilma Rantilla. « The effect of ozone on the production of broiler ». Thesis, Nelson Mandela Metropolitan University, 2004. http://hdl.handle.net/10948/226.
Texte intégralRésumé :
The aim of the study was to evaluate the effect of ozone (O3) on mature body weight (MBW), feed conversion rate (FCR), mortality rate (MR) and ammonia (NH3) production of broiler chickens (referred to as “broilers” in this thesis) under controlled conditions. Ozone was used for the purifying of air and water in order to eliminate harmful microorganisms. Two trials were conducted over a twelve week production period. In experiment 1, day old broiler chicks were randomly allocated to a control (n=130) and treatment (n=130) group. The treatment groups were exposed to ozone continuously for the entire period of the trial. Both air and water were ozonated on a 24 hours daily basis, while the control group was reared under normal commercial conditions. In experiment 2: day old broiler chicks were randomly allocated to a control (n=123) and a treatment (n=123) group. The treatment group was exposed to ozone for 3 hours per day for the entire period of the trial. Both air and water were ozonated, where the air was treated for 3 hours/day and the water for 1 hour/day during the entire production period. The control group was reared under normal commercial conditions. The results indicate that broilers exposed to continuous O3 (0.1 ppm) conditions had significantly higher (P< 0.001) mortality rates than the control group. The treatment group had a mortality rate of 55.38% compared to the 5.38% for the control group. No significant difference (P= 0. 2468) for MBW was found between the broilers that were reared in the O3 environment compared to the control iii group. Although the control group were on average 200g heavier at the end of the trial. No significant difference (p = 0. 6143) was recorded in FCR between the O3 and control groups. However the FCR of the broilers treated with O3 was lower by 100g than that of the control group. The O3 significantly (P< 0. 0001) reduced the NH3 in the treatment group. When the trial was repeated with limited exposure to an O3 environment there was no significant difference in MBW (P = 0. 0979), FCR (P = 0. 8913) and MR (P = 0. 1108) between the treatment and control groups. However, ammonia levels were lower in the treatment group compared to the control group. When the data was further analyzed comparing the two trials, the results indicated that there was no significant difference (P = 0. 4112) in the MBW for the broilers reared under normal conditions (control group) from experiment 1 and experiment 2, while a significant difference (P = 0. 0002) was recorded between the broilers reared under continuous O3 and regulated O3 conditions from experiment 1 and experiment 2 respectively. When the FCR data was analyzed using the Gompertz equation a significant difference (P = 0.0403) in the FCR of broilers reared in the control group between experiment 1 and experiment 2 was recorded (Table 8). No significant difference (P = 0.3226) in the FCR of broilers raised under O3 conditions of continuous and regulated O3 production were reported between experiment 1 and experiment 2. A highly significant difference (P = 0. 0001) in the MR of broilers reared under ozone conditions was recorded between experiment 1 and experiment 2. In experiment 1, the MR was 55.38% while in experiment 2 the MR was only 8.78%. A significant difference (P = 0.0355) was also recorded in the MR of broilers that iv were raised in the control groups between experiment 1 and experiment 2. The MR for broilers in the control group was 5.38% in experiment 1 and for experiment 2 it was 9.74%. The mortality rate of broilers raised in the control groups conditions increased by approximately 4% points or 81% between experiment 1 and experiment 2. The level (0.1 ppm) of ozone production had a limited effect on the MBW and FCR of broilers, however it is evident that ozone is toxic to broilers when they are exposed to a continuous ozonated environment. Ozone was however effective in controlling ammonia levels.
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Saenmahayak, Benya. « Complexed trace mineral supplementation of broiler diets ». Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Theses/SAENMAHAYAK_BENYA_52.pdf.
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Du, Plessis J. J. P. (Johannes Jacobus Pieter). « The effect of different dietary levels of energy and protein on the production and body composition of broiler breeders ». Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51966.
Texte intégralRésumé :
Thesis (MScAgric)--University of Stellenbosch, 2000ENGLISH ABSTRACT: A flock of 500 Hybro broiler breeders were employed to study the effect of different levels of protein and energy on production and body composition. The daily lysine intake of the birds were 900, 1050, 1200 and 1350 mg respectively, each fed in diets with a daily energy intake of 1800 and 2000 kJ ME to provide a 4 x 2 factorial design. Lysine was used as the reference amino acid in the experiment and all other amino acids were kept in a constant ratio in every experimental diet. The total production was divided into 3 periods of 13 weeks each (week 23 - 35; week 36 - 48 and week 49 - 61) to determine the effect of the treatments over time. Production was evaluated by hen day production; egg weight (g/egg); egg mass (g/day); fertility; hatchability; chicks/hen/week; feed conversion and day old chick weight. Hen day production was significantly (P < 0,05) lower at the high energy intake for period week 49 to 61. Energy and protein levels significantly increased egg weight. Effect of protein was consistent during all three periods of production. Egg mass output had a significant (P < 0,05) response to increasing levels of protein for the total period of production. The birds on the high energy diet produced a significant higher egg mass per hen during the first period of production (week 23 - 35). Hatchability was reduced (P < 0,05) by the higher energy intake for the total period of production and this effect was very significant (P < 0,01) during the final period of production. Similar to hen day production, the higher energy had a significant (P < 0,05) negative effect on the amount of chicks produced. The well-known correlation between egg weight and chick weight was confirmed with the regression equation: Chick weight = 10,5 + 1,22 x Egg weight. Both energy and protein had a significant (P < 0,01) positive effect on chick weight. The feed conversion was lower at increasing levels of amino acid intake (P < 0,01). Higher energy intake significantly (P < 0,05) increased hen weight and protein had a very significant effect during the first period of production (P < 0,01). The isotope dilution technique (tritiated water) was used to estimate the body composition of the breeders. This was done at 5 different periods (week 27, 35, 43, 52 and 61) of the production period to establish changes in requirements over time. Significant correlation were found between carcass moisture and waterspace (R2 = 0,76); fat % and carcass moisture (R2 = 0,78); protein % and waterspace (R2 = 0,35) and fat % and waterspace (R2 = 0,46). The regression equations obtained from these correlation were employed to determine excess energy and lysine consumed at different ages. Energy requirements were calculated according to the effective energy (EE) system and the conventional ME system. According to effective energy the lower energy intake was not sufficient and the maximum requirement was calculated to be 1942 kj EE/day. The metabolizable energy calculations indicated sufficient intakes at every treatment with the maximum requirement 1746 kj ME/day. The lysine requirement was found to be in excess of 1050 mg lysine per day. The recommendation for daily lysine intake is 1200 mg/day and the energy intake of breeders should be 1900 to 2000 kj ME/day from week 23 to 35 and can be reduced to 1800 kj ME/day in the final period of production.
AFRIKAANSE OPSOMMING: Om die effek van verskillende vlakke energie en proteïen op produksie en liggaamsamestelling te ondersoek is 'n trop van 500 Hybro braaikuiken teelouers gebruik. Die daaglikse lisien inname van die henne was onderskeidelik 900, 1050, 1200 en 1350 mg, wat elk by 'n daaglikse energie inname van 1800 en 2000 kJ ME verskaf is, in 'n 4 x 2 faktoriale ontwerp. Alle aminosure is in 'n konstante verhouding met die verwysings aminosuur lisien in die rantsoen ingesluit. Om te evalueer of daar veranderinge oor 'n tydperk plaasvind weens die verskillende behandelings is die produksie periode in drie periodes van 13 weke elk verdeel (week 23 - 35; week 36 - 48 en week 49 - 61). Die produksie standaarde wat gemeet is, is hen dag produksie, eiergewig (g/eier), eiermassa (g/dag), vrugbaarheid, uitbroeibaarheid, kuikens/hen/week, voeromset en dagoud kuikenmassa. Hen dag produksie was betekenisvol (P < 0,05) laer by die hoër energie innames in die laaste periode van 49 tot 61 weke. Energie en proteïen het eiergewig betekenisvol (P < 0,01) verhoog. Die effek van hoër vlakke proteïen was konstant in alle produksie periodes. Die daaglikse eiermassa (g/dag) het ook saam met stygende vlakke proteïen verhoog en hierdie effek was vir die totale periode van produksie. Energie het die eiermassa in die eerste periode van produksie (week 23 - 35) verhoog. Uitbroeibaarheid is verlaag (P < 0,05) vir die totale periode van produksie deur die hoër energie inname en die effek was selfs groter (P < 0,01) in die finale periode van produksie. In ooreenstemming met die hen dag produksie is die aantal kuikens geproduseer negatief beïnvloed deur die hoër energie inname (P < 0,05). Die korrelasie wat bestaan tussen eiermassa en kuikenmassa is bevestig deur die regressie: Kuikenmassa = 10,5 + 1,22 x Eiermassa. Energie en proteïen het kuikenmassa betekenisvol (P < 0,01) verhoog. Voeromset was laer by stygende vlakke van proteïen inname (P < 0,01). Die hoër energie inname het henmassa ook betekenisvol (P < 0,05) verhoog en proteïen het dieselfde effek slegs in die eerste periode van produksie gehad (P < 0,01). Die liggaamsamestelling van teelhenne is bepaal met behulp van die isotoop verdunnings tegniek (tritium water). Dit is bepaal op 5 verskillende stadiums in die produksie periode (week 27, 35, 43, 52 en 61) om die moontlike verandering in behoeftes oor tyd vas te stel. Betekenisvolle korrelasies is gevind tussen karkasvog en die waterspasie (RZ= 0,76); vet % en karkasvog (R2 = 0,78); proteïen % en waterspasie (R2 = 0,35) en vet % en waterspasie (R2 = 0,46). Die regressie vergelykings van hierdie korrelasies is gebruik om die hoevelheid surplus energie en lisien ingeneem te bepaal. Die" effective energy" sisteem en die konvensionele ME sisteem is gebruik in die bepaling van energie behoeftes. Volgens die " effective energy" was die energie inname nie voldoende by die laer energie innames nie en die maksimum behoefte is bereken as 1942 kJ EE/dag. Die maksimum energie behoefte volgens metaboliseerbare energie is bereken as 1746 kj ME/dag. Die lisien behoefte moet hoër as 1050 mg/dag wees. Die aanbeveling van die daaglikse lisien inname is 1200 mg/dag en die energie inname moet 1900 tot 2000 kj/dag wees tot 35 weke produksie en kan daarna verlaag word na 1800 kJ ME/dag.
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Lee, Jason Thomas. « Influence of dietary composition on coccidiosis vaccination efficacy in broilers ». Texas A&M University, 2006. http://hdl.handle.net/1969.1/4713.
Texte intégralRésumé :
This research program included a series of experiments to investigate the effect
of starter diet protein level on the performance of broilers vaccinated with Coccivac®-B
and subsequently challenged with a mixed species Eimeria challenge compared to nonvaccinated
broilers. Pre-challenge performance data indicates that vaccination may
decrease body weights and increase feed conversion ratio (FCR) with vaccination. The
time period associated with the observed effects is between 13 to 17 d of age. This
reduction in performance of vaccinated broilers versus non-vaccinated broilers was
eliminated by the conclusion of the experiments (27 d) in the higher protein diets.
Vaccination was effective at generating protective immunity against the Eimeria
challenge evidenced by significantly increased body weight gains, improved feed
conversions, reduced post-challenge mortality, and reduced lesion development in
vaccinated broilers compared to non-vaccinated.
The final experiment included the comparison of Coccivac®-B to Bio-Cox®
(salinomycin) for controlling field strain Eimeria in broilers reared on two different dietary rations varying in protein concentration. Diet A had a lower protein
concentration than Diet B. On day 14, Eimeria collected from commercial broiler farms
in Texas were spray applied to the litter in all pens. Broilers reared on Diet B were
heavier at Day 40 while body weights at day 50 were similar for all groups. Broilers fed
Diet B had lower FCR during the starter and finisher diets. Broilers fed salinomycin had
lower FCR for the starter and grower diets while vaccinated broilers had lower FCR
during the withdrawal period. Cumulative FCR for the entire grow out period were
similar for all groups.
These data indicate that vaccination can be utilized as an anticoccidial preventive
and are suggestive that reduced protein concentration of starter diets can lead to
significant losses in broiler performance when utilizing a vaccination program to prevent
coccidiosis. Feeding an appropriately formulated diet while vaccinating broilers with
Coccivac®-B as an alternative to the use of salinomycin yields at least equivalent if not
elevated performance in the presence of field-strain Eimeria during grow-out with no
effect on the cost of production.
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Hansson, Ingrid. « Bacteriological and epidemiological studies of campylobacter spp. in Swedish broilers / ». Uppsala : Dept. of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200763.pdf.
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Guo, Kunde. « Plasma lipoprotein metabolism and genetic variation of fatness in broilers ». Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/13966.
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Cruz, Carlos Eduardo Braga. « Calcium anacardate as anacardic source in the feed of broilers ». Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16333.
Texte intégralRésumé :
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorA pesquisa foi desenvolvida com o objetivo de avaliar os efeitos da adiÃÃo do anacardato de cÃlcio (ACC), como fonte de Ãcido anacÃrdico na raÃÃo de frangos de corte sobre o desempenho, as caracterÃsticas de carcaÃa, qualidade e a estabilidade lipÃdica da carne, parÃmetros sanguÃneos, atividade enzimÃtica e peroxidaÃÃo lipÃdica do fÃgado e no crescimento, composiÃÃo e qualidade dos ossos. Para isso, 840 pintos machos de um dia da linhagem Ag Ross 308 foram distribuÃdos ao acaso em seis tratamentos, com sete repetiÃÃes de vinte aves. Os tratamentos consistiram em: raÃÃo sem promotor de crescimento (PC); raÃÃo com PC e, os demais, raÃÃes sem o PC e adiÃÃo de ACC nos nÃveis de 0,25; 0,50; 0,75 e 1%. A adiÃÃo de ACC na raÃÃo nÃo influenciou nos parÃmetros bioquÃmicos do sangue (Ãcido Ãrico, creatinina, alanina aminotransferase, aspartato aminotransferase, colesterol total, HDL, LDL e triglicerÃdeos), na atividade enzimÃtica (superÃxido dismutase, grupos sulfidrÃlicos nÃo-protÃicos) e peroxidaÃÃo dos lipÃdeos do fÃgado, no crescimento e qualidade Ãssea (peso, comprimento, diÃmetro, Ãndice de Seedor, resistÃncia, deformidade, matÃria seca e matÃria mineral), nas caracterÃsticas de carcaÃa (% de carcaÃa, peito e coxa+sobrecoxa) e na qualidade da carne ( L*, a*, b*, pH, perda de Ãgua por cocÃÃo e capacidade de retenÃÃo de Ãgua). No entanto, a adiÃÃo a partir de 0,75% de ACC reduziu o ganho de peso e prejudicou a conversÃo alimentar dos frangos atà 21 dias de idade, porÃm, a adiÃÃo de atà 1% nÃo afetou o desempenho quando se considerou o perÃodo total de criaÃÃo (1 a 42 dias de idade). Para os valores de TBARS da carne, os nÃveis de 0,75% e 1% proporcionaram os menores valores, enquanto, o tratamento sem promotor de crescimento proporcionou maior valor. O ACC pode ser adicionado na raÃÃo dos frangos de corte atà o nÃvel de 1%, sem que ocorram alteraÃÃes nos parÃmetros sanguÃneos, enzimÃticos do fÃgado, no desempenho ao final do perÃodo de criaÃÃo (42 dias de idade), nas caracterÃsticas de carcaÃa e no crescimento, composiÃÃo e qualidade dos ossos. Contudo, a qualidade da carne pode melhorar com a reduÃÃo da oxidaÃÃo lipÃdica a partir de 0,75%.
The research aims to evaluate the effects of adding calcium anacardic (CAC) as a source of anacardic acid in the feed of broiler about the performance, carcass characteristics, quality and lipid stability meat, blood parameters, enzyme activity and lipid peroxidation liver and growth, composition and quality of the bones. For this, 840 male chicks with a day Ross 308 line were randomly assigned to six treatments, with seven replicates of twenty birds. The treatments consisted of: diet without growth promoter (PC); diet with PC and the others without PC and adding CAC levels of 0.25; 0.50; 0.75 to 1%. The addition of CAC in the feed didnât affect the biochemical blood parameters (uric acid, creatinine, alanine aminotransferase, aspartate aminotransferase, total cholesterol, HDL, LDL and triglycerides) in the enzyme activity (superoxide dismutase, non-protein sulfhydryl groups) and peroxidation of liver lipids, growth and bone quality (weight, length, diameter, Seedor index, strength, deformity, dry matter and mineral matter), in the carcass characteristics (% of carcass, breast and thigh + drumstick) and quality meat (L *, a *, b *, pH, loss of water by cooking and water holding capacity). However, the addition of from 0.75% CAC reduced weight gain and feed conversion detracted from the chickens up to 21 days old, however, the addition of up to 1 % did not affect performance when considering the total period (1 to 42 days old). For TBARS values for beef, the levels of 0.75% to 1% have provided the lowest values while treatment without growth promoter yielded higher value. The CAC can be added in the feed of broilers to the level of 1 %, no changes occur in the blood parameters and enzyme of the liver, the performance at the end of the growing period (42 days old), carcass characteristics and growth, composition and quality of the bones. However, the quality of the meat can improve with reduced lipid oxidation from 0,75. The CAC can be added in the feed of broiler until the level of 1%, without change the blood parameters, enzymatic liver, the performance at the end of the growing period (42 days old), carcass characteristics and growth, composition and quality of the bones. However, the quality of the flesh can be improved by reducing lipid oxidation as 0.75%.
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Cruickshank, John Johnston. « Morphometric and radiographic characterization of leg disorders in broiler chickens ». Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24601.
Texte intégralRésumé :
The objective of this study was to investigate the effects of cage density and excess vitamin D₃ on the incidence and severity of leg abnormalities in broiler chickens. In addition, sequential morphometric and radiographic
characteristics of leg bone development were described in normal and abnormal broilers in an attempt to develop a pattern recognition for leg abnormalities in poultry.
Twisted leg, characterized by a progressive medial (varus) or lateral (valgus) deviation of the distal tibiae was the predominant leg abnormality observed. Lateral deviations were more common than medial deviations (92% and 8%, repectively) and it occurred equally on the right and left leg. The incidence of twisted leg was considerably higher in cages than on litter (21% vs 4%, respectively).
High density and excess dietary vitamin D₃ resulted in a significant increase in the incidence of twisted leg. Differences in incidence could not be explained through differences in body weight or feed consumption. However, broilers fed the excess vitamin D₃ consumed more but gained less body weight, suggesting a metabolic stress may have been involved. High density appeared to increase the severity of the disorders, while excess vitamin D₃ had no effect on severity. Morphometric and radiographic comparisons of tibiae from normal broilers and those with twisted leg suggested that the development of twisted leg may be related to a structural abnormality in the distal tibiae; namely shallow distal condyle grooves. Changes in tibiae morphology associated with the progression of the disorder appeared as functional adaptations to the deformation rather than the primary cause of the bone deviations themselves.
Sequential radiography of tibae from clinically normal broilers revealed a high incidence of tibial dyschondro-plasia in the proximal metaphyses at 3, 4 and 5 weeks (60%, 20% and 20%, respectively). It was concluded that tibial dyschondroplasia may be more common than it is realized.Land and Food Systems, Faculty of
Graduate
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Rathore, Dinesh Singh. « Effect of allopurinol and hemin on some biological markers of aging in broiler chickens ». Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=784.
Texte intégralRésumé :
Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains xi, 77 p. : ill. Vita. Includes abstract. Includes bibliographical references.
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Brümmer, Mieke. « The effect of yeast cell wall preparations on salmonella colonisation, gastrointestinal health and performance of broiler chickens ». Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-04212008-112014.
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Huang, Ming-Kuei 1969. « The effect of two Lactobacillus strains and an acidophilic fungus on production and immune responses of broiler chickens / ». Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=78383.
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Three potential probiotics, Lactobacillus acidophilus, Lactobacillus casei and the fungus Scytalidium acidophilum were prepared in different ways. They were evaluated for their effects on performance and immune responses in broiler chickens in two 6-week trials. In the first trial, probiotics were orally administered at the ages of day 1 and day 8. There were no differences between live and disrupted cells. However, cobalt-containing cells had improved effects numerously in comparison with non cobalt-containing cells. As a result, these three disrupted probiotics, each in two different concentrations, were sprayed onto a mash basal feed before pelleting in the second trial. Improved feed intake (up to 6%) and body weight gain (up to 7%) were observed in all probiotic treatments. The anti-KLH IgA and IgG titers of probiotic-treated chickens were not significantly different from the negative controls in both trials. In summary, disrupted and cobalt-containing probiotics were proved to enhance the performance of broiler chickens and are promising for commercial application. In addition, a new fungal mycelium, Scytalidium acidophilum, was suggested to be a good probiotic to improve the growth of broilers.
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Shen, Shixue. « Differential gene expression in innate immunity between commercial broilers and layers ». [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1848.
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Everett, Derrick Lashawn. « LYSINE AND THREONINE RESPONSES IN ROSS X ROSS TP16 MALE BROILERS ». MSSTATE, 2009. http://sun.library.msstate.edu/ETD-db/theses/available/etd-03272009-114855/.
Texte intégralRésumé :
The purpose of this study was to evaluate the Lys and Thr responses of TP-16 male broilers. Experiment 1 (14-28 d of age) showed no significant live performance effects. In Experiment 2, Lys and Thr (P=0.021) interacted to affect 28 to 42 d body weight gain and (P=0.004) feed intake. Lys main effects improved body weight gain (P=0.002), and feed conversion (P=0.009). Thr fed at the 0.68% level improved body weight gain and feed conversion. Mortality did not differ among treatments and averaged 0.09% across all treatments. The study indicated the sensitivity of the Thr:Lys ratio when broilers are fed diets containing marginal Lys. Although Thr X Lys interactions occurred in this study, the Lys levels in the test diets may have been too high for determining a ratio to an amino acid in a factorial study. Interaction results indicate that the Thr:Lys ratio in broilers from 28 to 42 days of age is between 0.57 to 0.68.
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Wakeman, Wendy G. « Comparison of observed with predicted performance and body composition in broilers ». Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288078.
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Westergaard, Kyle Justin. « The response of broilers to acidification of drinking water and feed ». Diss., University of Pretoria, 2019. http://hdl.handle.net/2263/77898.
Texte intégralRésumé :
Alternatives to antibiotics are constantly being studied and one such alternative is organic acids. Organic acids can lower the pH in the gastrointestinal tract (GIT) and the lowered pH renders the environment unfavourable to pathogenic bacteria, thus resulting in a healthier GIT. This can enhance nutrient digestion, absorption and utilisation, as well as enhanced growth and efficiency of the bird.
The main objective of this study was to assess the optimal drinking water pH for broilers and what effects it would exhibit on the GIT. The second part of this study was to compare water acidification and feed acidification, as well as a combination thereof.
Two different feeds and five different water pH levels were fed to 7200 Ross 308 broilers, randomly allocated to 120 pens, with 12 replicates per treatment and 60 birds per pen. Feed 1 was considered as ‘standard’ and feed 2 was considered as ‘acidified’, containing 0.3% FORMI® (ADDCON 40% formic acid product). The five water pH levels tested were 3.0, 3.8, 5.5, 6.5 and tap water (pH of 7.9). Broiler performance and pH in various GIT segments were measured weekly.
The standard feed performed better than the acidified feed, irrespective of water pH. Standard feed resulted in significantly greater bodyweight (BW) and European performance efficiency factor (PEF) at weekly weighing intervals from 7-35 days, as well as significantly lower feed intakes (FI) and feed conversion ratio (FCR).The different water pH levels used throughout the trial showed clear trends and significant differences amongst the various treatments, irrespective of the feed used. Any level of drinking water acidification proved better than no acidification, with significantly higher BW and PEF on majority of the recordings, as well as significantly lower FCR and FI. Water intake was significantly higher for a water pH of 3.8 when compared to a pH of 7.9. When comparing the different drinking water pH levels across the two feeds, broiler performance always favoured the standard feed. Mortality was not significantly different and GIT pH was highly variable, showing no clear trends.
This study suggests that feed acidification is not as effective as water acidification and that a lower drinking water pH can significantly improve economically important measurements, such as BW and FCR. It can also be concluded that the effects exhibited on the pH of various GIT segments cannot be predicted. Based on this study, there is no clear benefit to combining feed and water acidification and a drinking water pH of 3.0 – 3.8 is recommended.Dissertation (MSc (Agric))--University of Pretoria, 2019.
Animal and Wildlife Sciences
MSc (Agric)
Unrestricted
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Zhang, Shuai. « Physiological and Biochemical Aspects of Methionine Isomers and Precursors in Broilers ». Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/71816.
Texte intégralRésumé :
Methionine (Met) is an essential amino acid for animals and also the first limiting amino acid in a broiler diet. The dietary supplemental Met sources include the natural isoform L-methionine (L-Met), the synthetic form DL-methionine (DL-Met) and the synthetic Met precursor DL-2-hydroxy-4 (methylthio)-butanoic acid (DL-HMTBA). The objective of this dissertation was to determine the effect of different dietary Met source supplementation and Met deficiency on a series of physiological and biochemical aspects, including growth performance, global DNA methylation and methyltransferase activity, blood antioxidant profile (e.g., acute phase protein, leukocyte count), intestinal nutrient transporter gene expression, Met converting enzyme gene expression and activity, oxidative stress markers, and a potential pathway related to amino acid signaling. To achieve this goal, male Cobb-500 broilers were raised from day of hatch (d0) to d35 post-hatch and fed a diet deficient in methionine and cysteine (Met + Cys) (control) or the same diet supplemented with 0.22% DL-Met, 0.22% L-Met or 0.31% DL-HMTBA (to provide 0.22% DL-Met equivalent) to meet Met + Cys requirements. Tissues (liver, breast muscle, duodenum, jejunum and ileum) and blood samples were collected at various ages from d0 to d35 for analysis. Met supplementation significantly improved body weight gain and feed efficiency compared to the Met deficient group, but no differences were observed among DL-Met, L-Met and DL-HMTBA for growth performance parameters (P > 0.05). Met supplementation had no effect on red blood cell packed cell volume, white blood cell differential count, hepatic total DNA methylation, DNA methyltransferase and Met oxidase activity, and had limited effects on activation of p70S6K, a key amino acid signaling protein (P > 0.05). Although dietary Met sources did not change oxidative status of the treated chickens, both L-Met and DL-Met but not DL-HMTBA supplementation decreased the level of acute phase protein serum amyloid A compared to the control group (P > 0.05). The effect of Met supplementation on gene expression of nutrient transporters and Met converting enzymes were complex and dynamic. Most of the target genes demonstrated tissue- and development-dependent expression patterns, with few significant treatment effects observed. L-Met and DL-Met but not DL-HMTBA supplementation enhanced the neutral amino acid transporters ATB0,+ and B0AT gene expression in various small intestinal segments. All three Met sources increased monocarboxylic acid transporter (MCT1) gene expression in the jejunum. DL-HMTBA and L-Met fed chickens showed greater hepatic L-HMTBA oxidase (HAO1) gene expression. DL-Met increased glutamic-oxaloacetic transaminase 2 (GOT2) gene expression in the duodenum. An in vitro study with tissue explants, however, did not demonstrate a similar gene expression pattern as that in the in vivo study. Lastly, RNA sequencing results illustrated that Met deficiency could lead to many differentially expressed genes but different supplemental Met sources had no influence on hepatic gene expression profiles. In conclusion, as common dietary supplemental Met sources, L-Met, DL-Met and DL-HMTBA exhibited similarity in impacting intestinal amino acid/peptide/monocarboxylic acid transporter gene expression and Met converting enzyme activity. The regulatory roles of Met as an antioxidant and nutrient signaling in cell metabolism were not affected by different dietary supplemental Met sources.Ph. D.