Dissertations / Theses on the topic 'Neat cattle'

To evaluate the importance of non-linear relationships between Relative net income per day of productive life (RNI/DPL) and individual traits, 921,915 potential offspring were simulated from all possible matings of 20,487 Jersey cows and 45 active AI sires. Predicted milk yield, fat yield, and 13 linear type traits of potential progeny were used to predict RNI/DPL of all potential progeny.

Five methods of mate selection and pairing were evaluated for their effectiveness in choosing mates and the amount of computer time required to choose those pairings. Results of a linear programming (LP) method were used as a comparison for the other four more easily applied methods. Two of the other four methods were not significantly (P > .01) different from the LP method. Although the random pairing method was significantly different, similarity of results, for this method indicated non-linear relationships between RNI/DPL and individual trait scores are of minor importance. A11 four methods used considerable less computer time than the LP method.

Analysis of variance for predicted RNI/DPL (all possible offspring) indicated herd, dam within herd, sire, and inbreeding class to be significant (P < .01) variables in determining RNI/DPL. However the sire by dam within herd interaction did not significantly affect RNI/DPL, again indicating non-linear relationships between traits and RNI/DPL were not very important.

Regressing PDâ s, Clâ s, and their crossproducts for milk yield, fat yield, and 13 linear type traits showed the relative importance of crossproducts to be minimal in comparison to the linear ellects of parental genetic evaluations.

Master of Science

Data for this study were age-adjusted linear scores on all cows scored between 1980 and 1993. Lifetime production information on these cows and their herdmates was used to calculate Relative Net Income adjusted for opportunity cost (RNIOC) for the 2,249,835 cows with an 84 month herdlife opportunity. The effect of inbreeding was analyzed using both a fixed and animal model, with little difference in results. Inbreeding depressed RNIOC by $12.69 in a fluid market and $11.53 in a manufacturing market per 1% increase in inbreeding. Addition of somatic cell information in the profit function had little effect. Heritabilities of profit functions were .16 and .14 for a fluid and manufacturing market, respectively. Animal model estimates of inbreeding depression were +.16 days, -6.7 days and -5.1 days for age at first freshening (AFF), days of productive life (DPL) and days in milk (TDIM), respectively. Inbreeding decreased first lactation mature equivalent milk, fat, and protein by 23.7 kg, .85 kg, and .76 kg, respectively and lifetime milk, fat, and protein production by 176.9 kg, 6.4 kg, 5.6 kg, respectively per 1% increase in inbreeding. Inbreeding had little effect on conformation traits. Effects of inbreeding were cumulative, exacting a larger effect on lifetime profit functions than on individual traits, when expressed as a percent of additive standard deviation. This study gives evidence that though not alarming, inbreeding has a deleterious effect on the lifetime performance of dairy cattle.
Master of Science

Microcomputer simulation was used to evaluate effects of all combinations of two levels of involuntary culling, heifer rearing, and sire selection against dystocia in heifers on timing and magnitude of net income in dairy cattle. Time to cumulative payoff of expenses and net income per day of herdlife were measured for herds and individual cows. Net income was accumulated monthly, and expressed per day of life and per day to 96 mo. Twenty herds of 80 cows were simulated for 20 yr under eight options in the herd study. More than 1000 cows with complete herdlives, from a single herd, were individually simulated for each of eight options in the cow study, with no voluntary culling of cows. For the herd study, milk yield per cow averaged 6838 kg ± 858 kg/yr, and net income per cow was $671 i $193/yr. Mean time to payoff was 60.0 mo, and mean net income to 96 mo, including salvage value, was $.36/d. Heifers calving at 26 mo had rearing expenses of $1030, time to payoff of 54.6 mo, and net income of $.432/d, compared with rearing expenses of $1200, time to payoff of 70.0 mo, and net income of $.285/d for heifers calving at 32 mo. Options with 12% involuntary culling paid off 2.3 mo earlier and had $.081 more net income per day than 24% involuntary culling. Differences in response variables due to sire dystocia and PD Dollars were minimal. Options with 26 mo age at first calving, 12% involuntary culling, and random mating had earliest time to payoff (54.0 mo) and highest net income ($.485/d). Options with 32 mo age at first calving, 24% involuntary culling, and random mating had latest payoff (74.3 mo) and lowest net income (S.246/d). Herds and years had large effects on time to payoff and net income due to differences in herd production and genetic trend of sires for production over time. Including salvage value for cows surviving 96 mo increased net income $.064/d for herds, and $.25/d for cows. Twenty-one percent of the value of increased milk yield was attributed to increased feed costs. For the cow study, cost of rearing heifers was $141 ± $127, mean time to payoff was 53.4 mo, and mean time to cumulative profit was of 56.5 mo. Cumulative profit represented positive cumulative net income for 12 consecutive mo, which included 69% of cows with time to payoff. Net income was $.19/d for all cows, $.46/d for cows with a first calving, $.60/d for cows surviving 96 mo, and $.85/d for cows surviving 96 mo including salvage value. Heifers calving at 26 mo paid off expenses at 47.1 mo, compared with 60.6 mo for heifers calving at 32 mo. Heifers calving at 26 mo cost $.07/d more to raise to first calving, but paid off by 70 d in milk into their second lactation, compared with payoff by 140 d in milk of the third lactation for cows calving at 32 mo. Regressions of time to payoff and net income per day at 96 mo on cow production were -.0077 d/kg and .00028 $/kg, respectively. The regression of time to payoff on PD Dollars was -.0035 d/PDS, and the regression of net income per day on PD Dollars was .00072 S/PDS for cows that calved. Differences did not exist in time to payoff between levels of involuntary culling and selection against dystocia. Heifer rearing was most important in this study due to large differences in time to payoff and net income as age at first calving changed. Sire selection against dystocia in heifers was least important due to the mating program used, with intermediate differences in payoff and net income between levels of involuntary culling.
Ph. D.

Afrikaner, Drakensberger, and Nguni are the South African (SA) landraces that played major roles in the social, cultural and economic history of SA. These breeds are valuable genetic resources for beef production and limited information is available for these breeds at the genome level. The aim of this study was to perform SNP discovery in these three breeds using whole genome sequencing. Ninety cattle representing the three breeds were used to identify more about 17.6 M putative variants including SNPs and Indels. DNA was extracted from blood and hair samples, quantified and prepared at 50ng/?l concentration for sequencing at the Agricultural Research Council Biotechnology Platform using an Illumina HiSeq 2000. The fastq files were used to call the variants using the Genome Analysis Tool Kit. A total of 4,369,879 (16% of the total SNPs) were identified as novel. Annotation of these variants classified them into functional categories. Within the coding regions, 43% of the SNPs were nonsynonymous substitutions that encode for alternate amino acids. Functional enrichment analysis of novel SNPs identified significant number of genes (p < 0.001) that were located within 5% of 1,481 100kb windows. Gene ontology terms identified genes such as MLANA and SYT10 that have been associated with coat colour and sense of smell in mouse, respectively, and the ADAMS3 gene has been associated with fertility in cattle. Furthermore, whole genome screening detected 688 candidate selective sweeps (ZHp Z-scores ? -4) across all three breeds, of which 223 regions were assigned as being putative selective sweeps (ZHp scores ? -5). We also identified 96 regions with extremely low ZHp Z-scores (? -6) in Afrikaner and Nguni. Several genes such as KIT and MITF that have been associated with skin pigmentation in cattle, and CACNA1C, which has been associated biopolar disorder in human were identified in these regions. Breed-specific SNPs (2,272,667) were identified across the breeds and only 186 of these SNPs were identified as putative breed-specific SNPs. These SNPs were further tested for their ability to assign individuals to a breed and need further validation. This study provides the first analysis of sequence data to discover SNPs in indigenous SA cattle breeds. These results provide insight into the genetic composition of the breeds and offer the potential for further applications in their genetic improvement.
Thesis (PhD)--University of Pretoria, 2017.
Animal and Wildlife Sciences
PhD
Unrestricted

Orientador: Euclides Braga Malheiros
Resumo: A pecuária de corte brasileira tem sido pressionada no sentido de cada vez obter melhores resultados, o que força os proprietários a utilizar práticas e manejos específicos, os quais possibilitarão a manutenção dentro da atividade. Este estudo teve como objetivos avaliar o uso de inteligência artificial, mais especificamente redes neurais artificiais (RNA), para predizer resultados futuros tanto da produção de pasto quanto animal. Determinar dentre diversos cenários de recria e terminação de bovinos de corte em pastagens tropicais, qual foi o melhor cenário no que diz respeito aos resultados econômicos. Avaliar dentre diferentes doses de adubação nitrogenada, qual foi aquela que retornou melhores índices econômicos. As RNA se mostraram melhores que as regressões normalmente utilizadas para predizer as produções de pastagem (valores médios obtidos pelo uso das RNA foram 0,84; 0,78 e 0,75 para massa de forragem, porcentagens de folha e colmo, versus 0,74; 0,39 e 0,50 obtidos usando regressão linear múltipla) e animal (0,72 [RNA] e 0,67 regressão). No estudo referente aos cenários, os melhores resultados foram obtidos quando utilizado apenas sal mineral (lucratividade de 26,3%; período de “payback” simples igual à 11 ciclos e taxa interna de retorno de 9,30%) na recria dos bovinos de corte e na terminação, quando as variáveis climáticas possibilitaram via manejo de pastagem o uso de maior taxa de lotação (3,18 UA ha-1) na área. Quando avaliados os efeitos das doses de adubação n... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Brazilian beef cattle has been under pression to obtain better results, which drives owners to use specific practices and management, which will allow the maintenance within livestock. This study aimed to evaluate use of artificial intelligence, specifically artificial neural networks (ANN), to predict future results both forage and animal productions. Determine between a lot of rearing and finishing phase scenarios of beef cattle production using tropical pastures, how was the best scenario considering economic results. Evaluate between different nitrogen fertilizers levels, how was there obtained best economic indexes. The ANN was better than regressions normally used to predict forage production (mean values obtained by ANN use were 0.84, 0.78 and 0.75 for forage mass, leaf and stem percentages, versus 0.74, 0.39 and 0.50 obtained using multiple linear regression) and animal (0.72 [ANN] and 0.67 regression). Into study about scenarios, the best results were obtained when used mineral mix just (profitability of 26.3%, simple payback period equal to 11 cycles and internal return ratio of 9.30%) during rearing phase of beef cattle. During finishing phase, the best results occurred when weather variables allowed by pasture handled, the use of higher stocking rate (3.18 AU ha-1) into area. The evaluation of economic results caused by different nitrogen fertilizer levels. Allowed to say that was possible to observe that there was linear increase both on costs, and gross revenue,... (Complete abstract click electronic access below)
Doutor

The decline in greater sage-grouse (Centrocercus urophasianus; sage-grouse) populations across western North America has been primarily attributed to loss and fragmentation of their sagebrush (Artemisia spp.) habitats. This habitat loss is largely the result of increased human activities, with grazing by domestic livestock as the most predominant land use across the sagebrush ecosystem in North America. The goal of my research was to increase our understanding of the effects of livestock on sage-grouse populations. I reviewed the peer-reviewed literature for all published studies that reported potential effects of grazing on grouse species worldwide. I found that there was an overall negative effect of domestic livestock grazing on grouse populations in general. I compared sage-grouse nest success on two study sites managed under differing prescribed livestock grazing practices to determine their relative effects on sage-grouse nest survival. I found that nest survival was slightly higher in areas managed under high-intensity low-frequency rest-rotation practices. The difference was not statistically significant (P < 0.05). However, these areas received lower precipitation and were grazed at a higher stocking rate (AUM · ha-1) without negatively affecting nest survival compared to areas of that were mostly grazed as single pastures from May-September. Because livestock grazing in the sagebrush ecosystem has been historically facilitated with sagebrush reduction treatments to increase forage for livestock, I compared the relative effects of these treatments with the more direct effect from livestock grazing. Sagebrush treatments were found to have a greater effect on female sage-grouse survival than livestock grazing. This understanding can be useful for land managers looking to attenuate the effects of management decisions related to livestock grazing systems in the sagebrush ecosystem.

Range cattle grazing in semi-arid regions are commonly limited by lack of nutrients from low-quality forage. Due to this, ranchers are faced with the challenge of monitoring diet quality in order to address nutrient limitations. Near infrared spectroscopy (NIRS) of fecal samples is a method used to determine diet quality values like crude protein (CP) and digestible organic matter (DOM) in grazing animals. When combined with a nutritional balance analyzer such as the NUTBAL system, fecal NIRS can be used to monitor diet quality and project animal performance. Our research aimed to test the ability of NUTBAL to project animal performance as represented by body condition score (BCS) in cattle (n=82 Animal Units) grazing on the Santa Rita Experimental Range (SRER) in southern Arizona. Previous work conducted on other Arizona rangelands led to the hypothesis that fecal NIRS coupled with NUTBAL can be used to monitor diet quality and project BCS in a southern Arizona commercial grazing operation. Data collection occurred between June 2016 and June 2017. Standing biomass and botanical composition were measured before each grazing period, and relative utilization was measured following each grazing period. During the midpoint of grazing in each pasture, 30 body condition scores and a fecal composite of 15 samples were collected. Fecal derived diet quality varied between a maximum of 10.75% CP and 61.25% DOM in early August 2016, to a minimum value of 4.00 % CP and 58.40 % DOM in March 2017. This study confirmed the ability of fecal NIRS paired with NUTBAL to project future BCS within 0.5 a score point more than 80% of the time in cattle grazing on the SRER. With this information, cattle managers in southern Arizona can better address animal performance needs and nutrient deficiencies.

This study was done by administering household surveys to 50% of the families in the three communities. Families were selected through stratified random sampling. This allowed us to determine how much families are exploiting species that have a significant level of production as well as whether they use them for a commercial activity or subsistence. With regard to cows, 60.40 ± 4.72% of families use them. Each family has an average of 1.68 ± 0.21 cows. Productive cows make up 36.9% of the above percentage, which is a majority. The measured rate of production was 6.48 ± 0.25 L/cow/day. Overall, 40.16 ± 3.17% of production was used for household consumption while the rest was sold. These parameters as well as the sale of live animals helped San Nicolas have an annual income of 735 US dollars, which shows that this community relies more on commercial activity. On the other hand, San Clemente and San Francisco had annual incomes of 367 and 279 US dollars respectively. This shows that these communities focus more on familial subsistence. Of the major species, sheep are the least exploited with 54.80 ± 8.74% of families using them. The first lambing occurs at 17.79 ± 0.48 months. Newborns are weaned at 5.57 ± 0.11 months by only 27.27 ± 4.47% of families. Of the weaned newborns, 60.69 ± 5.13% are kept and the rest are sold. Every 10.46 ± 0.47 months, 77.96% of the wool produced is sold. Generally, the sheep are sol d at 22.84 ± 1.75 months of age. This generates an average annual income of 40.85 ± 19.26 US dollars, which indicates that this activity is focused on familial subsistence. Swine production is the most common form of animal production. Pigs are exploited by 81.86 ± 7.17% of families with each family having an average of 2.11 ± 0.16 animals. A sow’s first delivery occurs at 16.48 ± 0.48 months and their productive life comes after reproducing 1.98 ± 0.15 times. Each litter has 5.72 ± 0.19 offspring with a post-weaning mortality rate of 28.99 ± 4.82%. Offspring are weaned at 2.90 ± 0.12 months. Overall, 65.13% of the weaned offspring are kept and the rest are sold. Annual revenue from pig production is 63.2 ± 22.46 US dollars which indicates it is used for familial subsistence, acting as a safeguard against economic emergencies at times. Of the minor species, the guinea pig is the most exploited. It is used by 86.11 ± 3.65% of families with each family having an average of 12.04 ± 1.31 guinea pigs. The mothers have an average of 2.44 ± 0.06 offspring per litter with a weaning rate of 75.81 ± 4.33%. Overall, 86.91% of production is used for family consumption and the rest is sold. The annual income generated by this activity is 6.24 ± 0.51 US dollars which indicates that this is an activity dedicated to providing food for the family. Rabbits are used by 49.42 ± 5.23% of families, each having an average of 4.03 ± 0.64 animals. There is an average of 6.57 ± 0.29 newborns per litter with a weaning rate of 41.16 ± 5.20%. Overall, 80.18 ± 4.16% of production is used for family consumption. This activity is similar to guinea pig production seeing as the annual income it generates is only 12.80 ± 1.10 US dollars. Chickens are exploited by 77.33 ± 4.39% of families with each family having an average of 5.88 ± 0.60 animals. Broiler chickens make up 48.22% of the poultry population with the rest being made up of native and field hens. Overall, 68.96% of broiler chickens are used for family consumption while 89.31 ± 3.27% of hens are used for family consumption. The annual income from this activity is 40.13 ± 19.24 US dollars. This makes it appear to have a slight tendency toward commercial use. We conclude that the three communities have different levels of animal exploitation. San Nicolas was the most successful of the three, partially using their livestock production for commercial purposes. San Clemente used part of theirs for commercial purposes as well, but on a lower scale. San Francisco, on the other hand, focuses their livestock production solely on familial subsistence. We recommend that a study be conducted regarding all points involved in the feasibility of production projects in these communities, especially in regard to the organization in each community. This will help improve production levels and make way for a change from a subsistence based economy to a more commercially based economy, ultimately improving the social and nutritional levels of these families.

Two studies were performed to investigate the ability of a portable near-infrared spectrophotometer (NIRS) for on-site analysis of nutrient components in feces from cattle. In trial 1 of study 1, growing dairy steers were fed diets containing either 86 or 90% concentrate. Regression values from a calibration set of 56 samples were promising for CP, DM, and NDF, but not for ADF or starch. In trial 2 of study 1, finishing dairy steers were fed diets containing either thick (512 g/L) or thin (460 g/L) steam-flaked corn. Regression values from a calibration set of 126 samples were poor for all nutrients. Both studies showed statistically valid NIRS calibrations, but further validation was required to make regression values acceptable (R² > 0.80) for all fecal nutrient components. In study 2, NIRS analysis was employed on novel research. Young dairy bull calves were fed diets containing either whole or steam-flaked corn from pre-weaning until 8 weeks post-weaning when the first animal was heavy enough for inclusion into a commercial feedlot. Again, although statistically valid, regression values from a calibration set of 220 samples were promising for CP and ADF, but not predictive for DM, NDF, ash, and starch. Growth performance parameters were similar between diets, with starch digestibilities diverging after weaning and changing to a Holstein starter diet. These 2 studies show that commercial and research application of a portable NIRS for on-site analysis of the nutrient composition of feces from young, growing, and finishing dairy steers statistically possible but requires further validation research. Also, results from the second study imply that there is no advantage in feeding steam-flaked corn to dairy calves from pre-weaning to 8 weeks post-weaning or until reaching feedlot weight. However, starch digestibility begins to improve for steam-flaked corn to whole corn once the animal has been weaned.

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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
Steers were used as experimental host for Amblyomma cajennense and Boophilus microplus during simultaneous infections on ears and quarters. Thus, the study shows especifically teleoginas and quenoginas weight, egg production, eclodibility and oviposition period. The ticks were held in laboratoryconditions at 27?C and 70% UR. It was observed that teleoginas collected from the ears were lighter than those collected from hind quarters. Egg production index (EPI) and nutrient efficiency index (NEI) for A. cajennense was 45,74% and 60,36%, respectively, and for B. microplus was 42,58% and 59,51%, respectively. The eclodibility index from simultaneous infection was lower than individual infections. The correlation between teleogina weight and egg production for both ticks specie showed that the number of eggs was influenced by teleogina weight. The interaction between A. cajennense and B. microplus is reported for simultaneous infection on bovine.
Utilizando bovinos como hospedeiros, avaliou-se o comportamento de Amblyomma cajennense e Boophilus microplus em infesta??es simult?neas na orelha e anca, essa em ?reas de aproximadamente 60 cm2. O estudo focalizou prioritariamente o peso das tele?ginas, das quen?ginas, a produ??o de ovos, o tempo de ovipostura e a eclodibilidade. Os carrapatos foram criados em laborat?rio em estufa do tipo B.O.D. com temperatura controlada de 27? C e unidade relativa de 70 ? 10%, e mantidos isoladamente ap?s desprendimento do hospedeiro nas mesmas condi??es laboratoriais. As tele?ginas que ingurgitaram na orelha pesaram menos que as alimentadas nas ancas em ambas as esp?cies; o ?ndice de produ??o de ovos (IPO) e o ?ndice de efici?ncia nutricional (IEN) para A. cajennense e B. microplus foram 45,74 e 42,58%, e 60,36 e 59,5%, respectivamente. As taxas de eclodibilidade foram menores que as j? assinaladas para infesta??es individuais nas duas esp?cies. A correla??o entre o peso da tele?gina das duas esp?cies e a produ??o de ovos foi significativa, comprovando ser o n?mero de ovos ovipostos fun??o do peso da f?mea antes do ?nicio da postura. Concluindo-se haver intera??o entre A. cajennense e B. microplus em infesta??o simult?nea em bovinos.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A implementação de dados de sequenciamento de nova geração - “next-generation sequence” (NGS) em programas de melhoramento genético animal representa a mais recente ferramenta na utilização de dados genotípicos nos modelos de associação genômica, tendo em vista que todo polimorfismo é considerado nas associações entre registros fenotípicos e dados de sequenciamento. Como em toda nova tecnologia, a prospecção das variantes ainda representa um desafio no sentido computacional e de viabilidade dos custos para sua implementação em larga escala. Diante desses desafios, neste trabalho buscou-se meios de explorar os benefícios na utilização da NGS nas predições genômicas e superar as limitações inerentes a esse processo. Registros fenotípicos e genotípicos (Illumina Bovine HD BeadChip) de 2.279 animais da raça Gir (Bos taurus indicus) foram disponibilizados pela Embrapa Gado de Leite (MG) e utilizados para as análises de associação genômica. Além disso, dados de sequenciamento de 53 animais do 1000 “Bulls Project” deram origem à população de referência de imputação. Visando verificar a eficiência de imputação, foram testados diferentes cenários quanto a sua acurácia de imputação por meio da análise “leave-one-out”, utilizando apenas os dados de sequenciamento, que apresentaram eficiências de até 84%, no cenário com todos os 51 animais disponíveis após o controle de qualidade. Também foram verificadas as influências das variantes em baixa frequência na acurácia de imputação em diferentes regiões do genoma. Com a escolha da melhor estrutura da população de referência de imputação e aplicação dos controles de qualidade nos dados de NGS e genômicos, foi possível imputar os 2.237 animais genotipados, que passaram pelo controle de qualidade para dados de sequenciamento e realizar análise de associação genômica para as características produção de leite (PL305), teor de gordura (PG305), proteína (PP305) e sólidos totais (PS305), mensuradas aos 305 dias em animais da raça Gir leiteiro. Para tal, foram utilizados os valores genéticos desregredidos (dEBV) como variável resposta no modelo de regressão múltipla. Regiões de 1Mb que contivessem 100 ou mais variantes com “False Discovery Rate” (FDR) inferior a 0,05, foram consideradas significativas e submetidas a análise de enriquecimento por meio dos termos MeSh (“Medical Subject Headings”). As três regiões significativas (FDR<0,05) para PS305 foram observadas nos cromossomos 11, 12 e 28 e a única região significativa em PG305 foi no cromossomo 6. Tais regiões apresentaram variantes associadas com vias metabólicas da produção de leite, ausentes nos painéis comerciais de genotipagem, podendo representar genes candidatos a seleção.
- Implementing "next-generation sequence" (NGS) data in animal breeding programs represents the latest tool in the use of genotypic data in genomic association models, since all polymorphisms are considered in the associations between phenotypic records and sequencing data. As with any new technology, variant prospecting still represents a computational and cost-effective challenge for large-scale implementation. Front to these challenges, this work sought ways to explore the benefits of using NGS in genomic predictions and overcome the inherent limitations of this process. Phenotypic and genotypic (Illumina Bovine HD BeadChip) records of 2,279 Gir animals (Bos taurus indicus) were made available by Embrapa Gado de Leite (MG) and used for genomic association analysis. In addition, sequence data of 53 animals from the 1000 Bulls Project gave rise to the imputation reference population. In order to verify the imputation efficiency, different scenarios were tested for their imputation accuracy through the leave-one-out analysis, using only the sequencing data, which presented efficiencies of up to 84%, in the scenario with all the 51 animals available after quality control. Influences from the low-frequency variants on the accuracy of imputation in different regions of the genome were also verified. After identifying the best reference population structure of imputation and applying the quality controls in the NGS and genomic data, it was possible to impute the 2 237 genotyped animals that passed in the quality control to sequencing data and perform genomic association analysis for (PL305), fat content (PG305), protein (PP305) and total solids (PS305), measured at 305 days in dairy Gir animals. For this, unregulated genetic values (dEBV) were used as response variable in the multiple regression model. Regions of 1Mb containing 100 or more variants with a False Discovery Rate (FDR) lower than 0.05 were considered statistically significant and submitted to pathways enrichment analysis using the MeSh (Medical Subject Headings) terms. The three significant regions (FDR <0.05) for PS305 were observed on chromosomes 11, 12 and 28 and only one significant region in PG305, was on chromosome 6. These regions presented variants associated with metabolic pathways of milk production, absent in the panels genotyping, and may represent genes that are candidates for selection
convênio Capes/Embrapa (edital 15/2014)

O presente trabalho contextualiza a importância da determinação da viabilidade técnico-financeira em sistemas de produção de bovinos de corte, através da aplicação de uma análise técnica e econômica. O objetivo do presente estudo foi realizar uma análise produtiva e econômica de sistemas de produção de bovinos de corte na região do Pampa do Rio Grande do Sul. Foram analisadas quatro propriedades rurais pertencentes a uma empresa agropecuária, localizadas no município de Dom Pedrito, e denominadas como Sistema de Cria em Campo Nativo (SCN), Sistema de Cria com Agricultura (SCA), Sistema de Recria-Terminação (SRT) e o Sistema de Terminação (ST). Para avaliar o efeito da escala de produção sobre a eficiência da atividade, foi simulado um quinto sistema, denominado SIA (Sistema de Integração de Atividades), integrando todas as propriedades da empresa, por meio do somatório dos parâmetros físicos e econômicos dos quatro sistemas independentes. Posteriormente, foram gerados índices técnicos e financeiros para realizar a análise do SIA. A maior produtividade foi alcançada pela unidade SRT, seguida da unidade ST, com 296 e 98 kg.ha-1, respectivamente. Os sistemas SIA, SCN e SCA foram os menos produtivos dos cinco avaliados, com 88, 86 e 83 kg.ha-1, respectivamente. Entretanto, o SCN foi mais eficiente em termos econômicos que os demais sistemas. O custo de oportunidade e a mão de obra foram os itens que mais oneraram os sistemas de SCN, SCA e SIA, com 38,8 e 23,6%, 42,9 e 27,3% e 40,7 e 26,6%, respectivamente, enquanto que nos SRT e ST foi a aquisição de animais com 61,7 e 71,5%, respectivamente. Os resultados positivos de margem líquida dos sistemas SCN (0,96 R$.kg-1) e SRT (0,93 R$.kg-1) foram responsáveis pela viabilidade econômica do sistema simulado, que apresentou margem líquida de 0,04 R$.kg-1. O efeito na escala de produção demonstrou ser positivo entre os sistemas, pois houve diluição nos custos fixos de produção no sistema simulado.
This study contextualizes the importance of determining the technical and financial viability of beef cattle production systems through the application of technical and economic analysis. The aim of study was to evaluate the productive and economic analysis of a beef cattle production in the Pampa region of Rio Grande do Sul, Brazil. Data were collected from four properties from the same farming company, located in Dom Pedrito, RS. Production systems were defined as Cow-Calf System in Nature Pasture (CCNP), Cow- Calf in System and Agriculture (CCA), Rearing-Fattening System (RFS) and Fattening System (FS). We also simulated an additional system to evaluate the effect of production scale in the activity efficiency defined as Integration Activities System (IAS) that integrates all company farms. The IAS comprises the physical and economic parameters from four independent properties. The RFS farm had the highest productivity, with 296 kg.ha-1, followed by FS, IAS, CCNP and CCA. The RFS farm had the highest productivity, with 296 kg.ha-1, followed by FS, IAS, CCNP and CSA, with 98, 88, 86 e 83 kg.ha-1, respectively. The RFS showed highest productive and the CCNP demonstrated the highest economic results. The costs of opportunity and labour were higher for CCNP, CSA and IAS compared to RFS and FS, which have the animal’s acquisition as their main costs of production. The positives economic results of CCNP (0.96 R$.kg) and RFS (0.93 R$.kg-1) farms showed where responsible to economic viability of simulated system, that presented positive net margin (0.04 R$.kg-1). The effect on production scale was positive between systems by the attenuated on production fixed costs in the simulated system.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

O consumo alimentar residual (CAR) é uma medida de eficiência alimentar independente do crescimento e do peso à maturidade. O melhoramento genético para CAR pode reduzir o custo de alimentação de bovinos, porém uma melhor compreensão dos processos biológicos relacionados ao CAR é necessária. Além disso, associações entre CAR e qualidade de carcaça têm sido pouco investigadas em raças zebuínas. Desta forma, o objetivo com este estudo foi avaliar o metabolismo protéico, a composição corporal, as características de carcaça e a qualidade de carne em bovinos zebuínos com alto e baixo CAR. Adicionalmente, foi testada a hipótese da existência de interações entre CAR e peso vivo ao abate para características de carcaça e composição corporal. Setenta e dois novilhos da raça Nelore (16 a 21 meses de idade, 334±19 kg de peso vivo inicial [PV]) foram mantidos em confinamento e alimentados ad libitum (74,5% NDT; 14,3%PB) por 70 dias. O consumo de matéria seca (CMS) e o ganho médio de peso (GMD) diários foram medidos individualmente. Os 12 novilhos com maior CAR e os 12 com menor CAR foram classificados como grupos de alto e baixo CAR, respectivamente (fase de seleção) e foram alimentados até quando alcançassem pesos vivo ao abate de 460, 490, 520 e 550 kg (fase de terminação). Antes do abate, foi realizada colheita total de urina para a determinação da excreção diária de 3-metil-histidina e da taxa fracional de degradação miofibrilar. A composição química corporal foi estimada pelo método de diluição isotópica utilizando óxido de deutério. A maciez objetiva da carne e a atividade de proteases cálcio-dependentes foram determinadas no músculo Longissimus. Na fase de seleção, novilhos com baixo CAR tiveram menores CMS, conversão alimentar, CAR e ganho de gordura sobre a garupa que novilhos com alto CAR, mas nenhuma diferença foi observada no GMD, no PV final, na gordura subcutânea e na área do Longissimus. Na fase de terminação, nenhuma interação foi observada entre CAR e PV ao abate. Não houve diferenças entre animais mais e menos eficientes quanto ao peso e rendimento de carcaça, gordura renal, pélvica e inguinal, vísceras, área de Longissimus, gordura subcutânea, marmorização, aparas e porção comestível. Novilhos com baixo CAR apresentaram menos gordura sobre o trato gastrintestinal (TGI) que novilhos com alto CAR. Não foram observadas diferenças quanto ao índice de fragmentação miofibrilar, força de cisalhamento e atividade do sistema calpaína. As taxas fracionais de degradação, síntese e acréscimo protéico foram similares entre os grupos de CAR. Novilhos Nelore com baixo CAR depositaram menos gordura subcutânea na carcaça em pesos vivos entre 340 e 460 kg. Em pesos mais elevados (460-550 kg), as características de carcaça e a composição corporal não foram influenciadas pelo CAR, mas indivíduos menos eficientes apresentaram maior massa de gordura visceral. A seleção de bovinos zebuínos para baixo CAR pode diminuir a ingestão de alimentos e melhorar sua eficiência alimentar, sem comprometer a qualidade da carne.
Residual feed intake (RFI) is a feed efficiency trait that is independent of growth rate and mature weight. Genetic improvement in RFI may reduce the costs of feeding cattle, however a better understanding of biological processes underlying variation in RFI is necessary. Moreover, associations between RFI and carcass quality have been poorly investigated in Zebu breeds. Therefore, this study aimed to evaluate protein metabolism, body composition, carcass traits and meat quality in high- and low-RFI Zebu cattle. In addition, the hypothesis that there are interactions between RFI and harvest body weight for carcass traits and body composition was investigated. Seventy-two Nellore steers (16 to 21 month-old, 334±19 kg initial body weight [BW]) were fed a finishing ration (74.5% TDN, 14.3%CP) on an ad libitum basis, for 70 days. Daily dry matter intake (DMI) and body weight gain (ADG) were measured individually. The 12 lowest and the 12 highest RFI steers were classed as low- and high-RFI groups, respectively (selection phase), and were fed until reaching slaughter BW of 460, 490, 520 and 550 kg (finishing phase). Before slaughter, total urine was collected for determination of daily 3-methylhistidine excretion and myofibrillar protein breakdown rates. Body chemical composition was estimated by the isotope dilution method using deuterium oxide. Objective tenderness and Ca+2-dependent protease activities were measured on Longissimus muscle. In the selection phase, low-RFI steers had lower DMI, feed:gain, RFI, and ultrasound rump fat thickness gain than high-RFI cattle, but no differences were observed for ADG, final BW, ultrasound fat thickness and Longissimus area. In the finishing phase, no interactions were observed between RFI and slaughter BW. No differences between more and less efficient cattle were observed for hot carcass weight, dressing percentage, kidney, pelvic and inguinal fat, visceral mass, Longissimus area, backfat thickness, marbling score, trimmings and retail product yield. Low-RFI steers presented less fat on the gastrointestinal tract (GIT) than high-RFI cattle. No differences were observed for myofibrillar fragmentation index, Warner-Bratzler shear force and calpain system activities. Fractional rates of protein degradation, synthesis and accretion were similar between high- and low-RFI cattle. Low-RFI Nellore steers may store less subcutaneous carcass fat at body weights ranging from 340 and 460 kg. At higher body weights (460-550 kg), carcass traits and body composition are not affected by RFI, but least efficient cattle present greater visceral fat mass. Breeding zebu cattle for improved RFI may decrease feed intake and improve feed efficiency without compromising meat quality.

Dans un contexte où la consommation de viande bovine est en constante diminution, en partie à cause de sa composition lipidique, il apparaît important pour l'ensemble de la filière de pouvoir communiquer sur l’intérêt nutritionnel de cette viande et plus particulièrement sur sa composition en acides gras (AG). Pour que cette communication soit « efficiente » à tous les niveaux de la filière, il faut disposer de moyens analytiques fiables mais aussi faciles de mise en œuvre et de surcroît peu coûteux. La méthode analytique que nous avons choisi de tester est la spectrométrie proche infrarouge (SPIR) qui présente l’avantage d’être peu coûteuse, peu invasive et qui pourrait ainsi être utilisée à grande échelle et en routine en abattoir. Nous avons montré que la SPIR est performante pour déterminer les teneurs en AG saturés (AGS) et monoinsaturés (AGMI) (R2>0,9). Dans les meilleures conditions pour la prédiction des AGPI (échantillons comportant des teneurs élevées en AGPI et/ou une grande variabilité), les performances de prédiction restent encore insuffisantes (R2 <0,75). Pour pallier cette faiblesse de la SPIR, des équations de prédiction indirectes des AGPI ont été mises en place à partir des teneurs en AGS et AGMI, teneurs correctement déterminées par SPIR, et les informations disponibles en abattoir. Ces équations élaborées par régression linéaire multiple ont permis de prédire correctement les AGPI totaux et les AGPI n-6 (R2 >0,8). Elles restent perfectibles pour la détermination des AGPI n-3 totaux (R2=0,64) mais surtout pour le 18:3 n-3, le 20:5 n-3 et le 22:6 n-3 (R2 <0,55). L’objectif final de ce travail étant d'utiliser les équations en complément des mesures réalisées par SPIR à des fins industrielles afin de déterminer rapidement la composition en AG de la viande bovine, des études complémentaires seront nécessaires pour tester l'ensemble de notre démarche associant SPIR et équations de prédiction
In a context where the consumption of beef is declining in part because of its lipid composition, an opportunity to revive the beef industry is to communicate with consumers on nutritional quality of beef, especially its fatty acids (FA) composition. To ensure this communication is “efficient” at all levels of the industry, we must have reliable analytical resources but also easy to implement and also inexpensive. The analytical method proposed for determining the beef FA composition is the near-infrared spectroscopy (NIRS) which is inexpensive, minimally invasive and could thus be widely used in routine in slaughterhouse. We showed that NIRS was effective to determine the concentrations of saturated (SFA) and monounsaturated (MUFA) FA (R2> 0.9). Under the best conditions for the prediction of PUFA (samples containing high levels of PUFA and / or with a high variability), PUFA predictions were still not enough (R2 <0.75). So, to overcome this weakness of NIRS, indirect prediction equations of PUFA were performed from the SFA and MUFA contents correctly determined by NIRS and information available in slaughterhouses. These equations, developed by multiple linear regression, were used to correctly predict total and n-6 PUFA (R2> 0.8). These equations are still to be improved for the determination of the total n-3 PUFA (R2 = 0.64) and of the 18:3 n-3, the 20:5 n-3 and the 22:6 n-3 (R2 <0.55). Given that the ultimate aim of this research is to use the equations as a complementary tool in tandem with NIRS measurements to serve industry as a way to rapidly determine the FA content of beef, further studies will be needed to trial and test our novel coupled NIRS–prediction equations approach

"Resumo/Abstract", "palavras-chave/keywords" nos cap?tulos trabalho.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)
O comp?sito nFZV-CAG foi empregado para a ozoniza??o catal?tica heterog?nea da NMS em meio aquoso. O oz?nio foi gerado por uma central geradora de oz?nio IPABRAS, alimentada com ar. Foram avaliados diferentes processos catal?ticos como O3, CAG, O3-CAG, O3-nFZV- CAG, e a varia??o da concentra??o das nFZV para remo??o da NMS. Os resultados mostraram que a combina??o do O3-nFZV-CAG foi muito eficiente levando ? mineraliza??o de aproximadamente 70% da NMS em 120 min de rea??o. Tal efici?ncia pode estar atribu?da ao processo de eletr?lise, em que o Fe0 origina Fe2+ levando ? produ??o do radical hidroxila que ? altamente oxidante, levando a destrui??o do contaminante. As rea??es seguiram a cin?tica pseudo-primeira ordem para remo??o do f?rmaco. Ap?s realizada a coleta as amostras foram submetidas a an?lise qu?mica, empregando-se as t?cnicas de espectrofotometria de UV-Vis, cromatografia l?quida de alta efici?ncia (CLAE) e a determina??o da demanda qu?mica de oxig?nio (DQO) tamb?m foi realizada.
As nanopart?culas de FZV imobilizadas sobre a superf?cie do carv?o ativado (nFZV-CAG) foram sintetizadas e caracterizadas para remo??o do f?rmaco Nimesulida (NMS) em sistemas aquosos. Os estudos foram realizados em bateladas com agita??o de 250 rpm durante 120 minutos, onde foram avaliadas a efici?ncia, concentra??o (20, 25 e 30% do comp?sito) e diferentes dosagens (0,1 a 10g) de nFZV-CAG. Os resultados mostraram que a dosagem de 10 g de 20%nFZV-CAG removeu cerca de 80% da NMS 50 mg L-1 em apenas 30 minutos de rea??o, e atingindo 100% em 120 minutos. Foi observada ainda uma remo??o de 80% da DQO ao final da rea??o. As velocidades de rea??o aumentaram na medida em que foram aumentadas as dosagens do comp?sito, o que seria esperado. Por?m, com o aumento da concentra??o (%) de nFZV n?o houve aumento na velocidade das rea??es. As rea??es seguiram uma cin?tica de pseudo-primeira ordem em rela??o ? remo??o da NMS. Ap?s realizada a coleta, as amostras foram submetidas a an?lise qu?mica, empregando-se as t?cnicas de espectrofotometria de UV- VIS, cromatografia l?quida de alta efici?ncia (CLAE) e a determina??o da demanda qu?mica de oxig?nio (DQO) tamb?m foi realizada. Para caracteriza??o do comp?sito foram empregadas as t?cnicas Microscopia Eletr?nica de Varredura acoplada ? Espectrometria de Energia Dispersiva de Raios-X (MEV-EDS), que mostraram claramente a presen?a da nanopart?culas sobre a superf?cie do carv?o, e analise de superf?cie do nFZV-CAG e do CAG tamb?m foram realizadas.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.
The FZV nanoparticles immobilized onto the surface of the activated charcoal (nFZV-CAG) were synthesized and characterized for the removal of the pharmaceutical Nimesulide (NMS) in aqueous systems. The studies were performed in batch mode with stirring speeds of 250 rpm during 120 minutes, so that it was possible to evaluate efficiency, concentration (20, 25 and 30% of the composite) and different dosages (0,1 to 10g) of nFZV-CAG. The results showed that the dosage of 10g of 20%nFZV-CAG removed approximately 80% of NMS 50 mg L-1 in just 30 minutes of reaction, and reaching 100% in 120 minutes. It was still observed a removal of 80% of the COD (Chemical Oxygen Demand) at the end of the reaction. The reaction rates increased with the dosage of the composite, which was expected. Though, increasing the concentration (%) of nFZV did not result in higher reaction rates. The reactions followed a pseudo-first order kinetics for the removal of NMS. After the samples were collected, they were submitted to chemical analysis, employing the techniques of UV-VIS spectroscopy, high performance liquid chromatography (HPLC) and chemical oxygen demand (COD). In order to characterize the composite, the following techniques were used: Scanning Electron Microscopy (SEM) coupled with Energy Dispersive x-Ray spectroscopy (EDS), which showed clearly the presence of nanoparticles onto the charcoal surface. Analysis of the surface of nFZV-CAG were also performed.
The composite nFZV-CAG was used for the catalytic ozonation of NMS in aqueous media. The ozone was generated by an ozone generator IPABRAS, fuelled with air. Different catalytic processes were evaluated such as O3, CAG, O3-CAG, O3-nFZV-CAG, and the variation of the nFZV concentration for the removal of NMS. The results showed that the combination of O3- nFZV-CAG was very efficient, leading to the mineralization of approximately 70% of NMS in 120 minutes of reaction. Such efficiency can be attributed to the electrolysis process, in which the Fe0 generates Fe2+ which generates hydroxyl radicals that are highly oxidant, leading to the destruction of the contaminant. The reactions followed the pseudo-first order kinetics for the removal of the pharmaceutical. After the samples were collected, they were submitted to chemical analysis such as, UV-VIS spectroscopy, high performance liquid chromatography (HPLC) and chemical oxygen demand (COD).

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library.
Net feed intake or residual feed intake is the feed intake of an animal after adjustment for its average weight and weight gain while on the feed test. High net feed efficiency (NFE) animals have a low net feed intake, so the aim is to select animals that have high net feed efficiency in order to reduce the 70% expenditure for feed costs. Thus far, very few studies have been undertaken on beef cattle to identify genetic markers for NFE and to understand the molecular genetics of feed intake regulation and energy balance. Therefore, in an attempt to identify genes and metabolic pathways controlling feed efficiency in beef cattle, three different experimental approaches were taken herein: a) linkage and linkage disequilibrium quantitative trait loci (QTL) mapping for net feed intake in Lirnousin x Jersey animals, b) mitochondrial oxidative phosphorylation enzyme assays in high and low NFE cattle, and c) 2-dimensional fluorescent gel electrophoresis (DIGE) proteomics analysis of mitochondrial proteins. For the cattle QTL mapping, the results from a previous trial were utilized. In the trial, a double back-cross design was employed using two extremely divergent Bos taurus breeds [Jersey (J) dairy breed and Limousin (L) beef breed]. These breeds known to differ in many traits including carcass composition, fat colour, body size, and meat tenderness. Three first cross (F1=X) sires were mated to pure Jersey or pure Limousin cows, creating in total 366 XJ and XL backcross progeny (range 120-156 progeny per sire). The amount of feed consumed each day during the 70-100 day test was recorded electronically for each animal. Feed intake data were processed by calculating the least-square means for each animal over the test period. The data for net feed intake were analysed using a QTL half-sib interval-mapping model. The interval linkage analysis of whole genome detected six suggestive QTL (BTA 1, 6, 8, 9, 16, and 20) segregating for NFE. Of these 6 QTL, 4 NFE QTL (BTA 1, 6,16, and 20) were homeologous to QTL for NFE observed in fullsib F2 families of mouse selection lines (Fenton 2004). After the NFE data were reanalysed for outliers, a QTL on BTA 11 was re-ranked and placed in the top 4 NFE QTL in terms of size of effect and statistical support, whereas the OTL on BTA 6 and BTA 16 had less support. Since the QTL on BTA 9 was not independent of growth, only 4 QTL (BTA 1, 8, 11 and 20) were targeted for further study herein. These NFE QTL were cross-validated in Angus NFE selection line animals in collaboration with Department of Primary Industries (DPI), Victoria by microsatellite linkage mapping. Two of the QTL on BTA 8 and 20 were confirmed and three other minor QTL on BTA 1, 11, and 20 were detected in the Angus animals. Based on this background information, a comparative genome mapping study was undertaken to identify candidate genes. Using the human and bovine genome Ensembl databases, 205 NFE candidate genes underlying the 4 major QTL regions (BTA 1, 8, 11, and 20) were identified and 61 were sequenced in the mapping F1 Limousin x Jersey mapping sires. In these 61 genes, 308 SNPs were discovered, of which 27 were potentially functional SNPs changing the amino acids. 84 SNPs were selected for genotyping and used for fine mapping the 4 QTL and for SNP association studies with NFE. From the positions of the analyses, the 4 NFE QTL were refined and 27 candidate SNPs in 20 genes showed strong association with NFE in the Limousin x Jersey animals. A ParAllele whole genome scan with a bovine 10K SNP chip was also performed on a subset of the Angus NFE selection line animals by DPI Victoria. 100 ParAllele SNPs had significant association with NFE in the Angus selection line animals. These ParAllele SNPs were tested in the Limousin x Jersey animals and 16 ParAllele SNPs were significantly associated with NFE. Four of these SNPs were located in the NFE QTL on BTA 1, 11 and 20. Based on the candidate genes underlying the 4 NFE QTL, 8 potential metabolic pathways contributing to NFE were identified. These metabolic pathways included mitochondrial oxidative phosphorylation and glucose turnover. Therefore, to determine if these specific pathways are indeed involved in net feed efficiency, oxidative phosphorylation enzyme assays and mitochondrial protein profiling were conducted on progeny from the Angus Trangie NFE selection line animals. Liver and skeletal muscle samples were obtained from extreme high and low NFE animals with an average phenotypic difference of 3 kg net feed intake per day. Using these liver and muscle samples, mitochondria were prepared and assessed. The mitochondrial preparations were assayed for enzyme activity of 3 complexes (Complex I, II and IV) involved in oxidative phosphorylation. The enzyme activities were measured spectrophotometrically and analysed by regression analysis. The activity of the liver mitochondrial Complex I was found to be significantly decreased in the high NFE animals compared to the low NFE animals (p1.5 fold difference) in the high vs. low NFE cattle unambiguously identified a total of 27 proteins in 6 physiologically different groups. The mitochondria proteomics results also confirmed the involvement of oxidative phosphorylation in net feed intake regulation. Eleven oxidative phosphorylation complex subunit proteins were found to be differentially expressed between the high and low NFE animals. Other differentially expressed proteins included six stress-related proteins, seven energy production and glucose turnover proteins, two protein turnover and nitrogen balance enzymes, and two proteins involved in mitochondrial DNA and protein biosynthesis. Four of the differentially expressed proteins were found in the NFE QTL regions. The results of these experiments provide a better understanding of the relationship between variation in feed efficiency and cellular energy production mechanisms in beef cattle. The proteomics and mitochondrial enzyme assay results suggest that energy metabolism and homeostasis may not be an efficient process in low NFE cattle. Lastly, a set of candidate SNPs are now available for the further validation as markers for selection of NFE in cattle breeding programs.
http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1349183
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

For more than thirty years, studies about the effect of the exchange rate on exports have been conducted. However, few have considered the combined effect of the exchange rate on imported inputs into the agricultural system and the exports of final agricultural products those inputs produce. This work contributes to the agricultural economics literature by combining those effects. A current concern is for the net effect as the total value and quantity of inputs imported has increased. This research examines the effect of the exchange rate on imported inputs into the corn, wheat, and beef cattle production systems, breaking it down to a producer's budget, examining how the exchange rate affects profitability. Vector Autoregression (VAR) and Bayesian Averaging of Classical Estimates (BACE) models were estimated to evaluate the effects. Daily and weekly price data were used for corn, wheat, feeder steers, ethanol, diesel, ammonia, urea, di-ammonium phosphate, and the exchange rate. A VAR model was estimated to model the relationship between the variables. After having incongruous test results in determining the lag length structure it was decided that a BACE model would be approximated. After estimating the BACE model, the price responses of the commodities to the exchange rates were estimated. The price responses were used in demonstrating the effect of the exchange rate on a producer's profitability. It was determined that, generally, a strengthening exchange rate has a negative impact on prices. It was also found that the exchange rate has a greater impact on prices now than it did 14 years ago, implying that the exchange rate now has a greater affect on profitability. A one percent increase in the value of the dollar led to a decline in profitability ranging from $0.02/bu in wheat to $0.56/cwt in feeder steers. However, agricultural producers should not be overly concerned about a lower valued dollar from the perspective of their agricultural business.

The objectives of this study were to evaluate the effects of residual feed intake (RFI) classification on performance, feed efficiency, feeding behavior and carcass traits, and to determine the relative importance of individual performance and carcass measurements on between-animal variation in net revenue of feedlot steers. Performance, feed intake and feeding behavior traits were measured in 508 Angus-based composite steers, using the GrowSafe feed-intake measurement system, while fed a high-grain diet for 70 days. Residual feed intake (RFI) was computed as actual minus expected dry matter intake (DMI) derived from regression of DMI on average daily gain (ADG) and mid-test BW0.75, and steers classified into low (n = 150), medium (n = 200) and high (n = 158) RFI groups. Following the feed-intake measurement periods, steers were fed the same diet in group pens and harvested at an average backfat thickness of 1.14 cm. Net revenue (NR) was calculated as carcass value minus feeder calf, yardage, and feed costs using 3-year average prices. Feed cost was based on actual feed consumed during the feed-intake measurement periods, and model-predicted intake adjusted for RFI during the group-feeding periods. Steers with low RFI had $48/hd lower (P < 0.0001) feed cost, $16/hd numerically higher (P = 0.29) carcass value, and $62/hd more favorable (P < 0.0001) net revenue compared to their high-RFI counterparts. Net revenue was correlated with carcass weight, marbling score, yield grade, DMI, ADG, RFI and G:F ratio where animals that consumed more feed, had higher rates of gain and were more efficient had more favorable net returns. Models predicting net revenue from performance, carcass quality, and feed efficiency traits accounted for 77% of the between-animal variation in NR. In the base model, that included all traits performance, carcass quality and feed efficiency traits explained 28, 14 and 35%, respectively, of the variation in NR. Results from this study indicate that between-animal variation in net revenue was impacted to a great extent by performance and feed efficiency, rather than carcass quality traits, in Angus-based composite steers based on average 3-year pricing scenarios.

Tese de mestrado em Biologia Humana e Ambiente, Universidade de Lisboa, Faculdade de Ciências, 2020
De acordo com a Organização Mundial de Saúde, as doenças transmitidas por vetores representam mais de 17% de todas as doenças infeciosas no mundo, originadas por agentes patogénicos como vírus, bactérias e parasitas. A distribuição destes agentes tem vindo a ser afetada pela recente combinação de fatores como a globalização comercial, o transporte rápido e acessível e o menor rigor das regulamentações internacionais de saúde em viagens, causando o aumento da disseminação de parasitas e de vetores para novas áreas geográficas, colocando populações de humanos e outros animais, anteriormente não expostos, em risco de infeção. Os insetos do género Culicoides (Diptera: Ceratopogonidae) possuem uma grande importância na saúde animal e humana, uma vez que as fêmeas hematófagas são vetores de vários agentes patogénicos, como vírus (Língua Azul, Peste Equina Africana e Schmallenberg), filarídeos (Mansonella spp.), entre outros. Por sua vez, as fêmeas do género Culicoides são responsáveis por elevadas perdas económicas a nível mundial. Um conhecimento mais aprofundado da fauna de Culicoides presente em cada país é necessário, assim como as suas preferências ecológicas, de modo a que medidas possam ser aplicadas de modo mais eficaz e sejam criadas diferentes estratégias de controlo. A doença da Língua Azul é uma doença viral, não contagiosa que afeta ruminantes domésticos e silváticos, que foi reconhecida e descrita há mais de 230 anos na África do Sul. O vírus da doença da Língua Azul era transmitido por vetores endémicos de regiões tropicais e temperadas até meados dos anos 90 do século XX. No entanto, nos últimos anos têm ocorrido mudanças drásticas na distribuição mundial destes vetores portadores de vírus, particularmente na Europa desde 1998, onde surgiu na região sul do continente, muito possivelmente devido à introdução de hospedeiros ou produtos infetados, provenientes de regiões endémicas, ou às alterações climáticas que permitiram a persistência do vírus durante o inverno e a expansão para norte de Culicoides imicola Kieffer, 1913, o principal vetor da doença. Além disso, desde 2006, novos casos da doença foram reportados em regiões mais a norte da Europa, onde a espécie Culicoides imicola não existe, indicando que outras espécies, como as pertencentes ao grupo Obsoletus, têm competência vetorial. No entanto, existem poucos estudos sobre a associação entre Culicoides e animais silváticos e, por isso, o papel destas espécies devia ser investigado, já que a alimentação oportunista em diferentes hospedeiros pode facilitar a transferência de vírus entre animais silváticos, domésticos e até em humanos. Neste projeto, foram realizadas capturas de espécies perto de animais silváticos (girafas, zebras e aves) no Jardim Zoológico de Lisboa, entre maio de 2018 e setembro de 2019, e perto de bovinos domésticos da Faculdade de Medicina Veterinária da Universidade de Lisboa, entre junho e setembro de 2019 (excluindo o mês de agosto por ser período de férias de verão). Além dessas capturas, foram selecionadas capturas mais antigas de uma quinta em Leiria, realizadas em 2010 durante o Plano Entomológico de Vigilância Nacional para a doença da Língua Azul em Portugal (2005-2013), que foram utilizadas para comparar capturas mais antigas com as mais recentes. Como o conhecimento dos padrões de alimentação das diferentes espécies de Culicoides é essencial para o conhecimento da sua capacidade vetorial e como a determinação das preferências de hospedeiros clarifica o papel destas espécies na epidemiologia das diferentes doenças, os objetivos específicos deste trabalho são compreender melhor a distribuição destas espécies de Culicoides entre: i) animais silváticos e bovinos domésticos; ii) três animais silváticos diferentes: girafas, zebras e aves; iii) bovinos domésticos: Leiria, capturas mais antigas e Lisboa, capturas mais recentes e iv) detetar e identificar através de análise molecular as anomalias morfológicas em Culicoides do grupo Obsoletus. Para tal, os Culicoides foram capturados com recurso a armadilhas luminosas do tipo CDC, que são utilizadas durante o período noturno. Os insetos capturados foram analisados morfologicamente, mostrando a variação das espécies de Culicoides nestes locais. As capturas realizadas nos meses entre junho, julho e setembro de 2019 no Jardim Zoológico de Lisboa e na Faculdade de Medicina Veterinária foram comparadas e, os resultados demonstraram que de um total de 135 exemplares capturados perto de animais silváticos, foram capturadas oito espécies diferentes. Por outro lado, foram identificadas, perto de bovinos domésticos, sete espécies de Culicoides de um total de 158 exemplares. Destas espécies que foram identificadas nos dois locais é de notar que a maior abundância vai para os principais vetores da doença na Europa, C. imicola e espécies pertencentes ao grupo Obsoletus (C. obsoletus e C. scoticus). Este resultado pode suportar o papel putativo destas espécies como ponte de transmissão de arbovírus entre animais silváticos e ruminantes domésticos que, consequentemente, uma vez introduzidos e sob as condições ideais, se disseminarão rapidamente por grandes regiões da Europa. Em Portugal, este é o primeiro estudo realizado da fauna de Culicoides capturados perto de animais silváticos e a sua comparação com capturas realizadas perto de ruminantes domésticos. A monitorização da fauna de Culicoides em ambiente de zoo é importante para evitar o potencial risco de introdução de doenças vindas de animais importados. Neste contexto, as capturas foram realizadas no Jardim Zoológico de Lisboa entre maio de 2018 e setembro de 2019, de onde foram coletados 1088 exemplares, dos quais 71% capturados perto de girafas, 28% perto de zebras e apenas 1% perto de aves. Uma vez mais, as espécies mais capturadas foram C. imicola e aquelas pertencentes ao grupo Obsoletus. Em relação à comparação dos resultados obtidos, com um distanciamento de nove anos nas explorações de gado de Leiria em 2010 e de Lisboa em 2019, é importante verificar que ocorreu uma queda acentuada no número de exemplares capturados. Esta redução, provavelmente, pode ter ocorrido devido ao ano quente e seco que se fez sentir em 2019 que dificultou a criação de condições favoráveis para o surgimento de Culicoides. Além disso, a composição de Culicoides nestas duas capturas revelou que as espécies pertencentes ao grupo Obsoletus foram as mais capturadas, representando 71% das capturas em 2010 e 81% das capturas em 2019. A segunda espécie mais capturada em ambos os anos foi C. punctatus, sem diferenças significativas na composição de ambas as capturas. Além disso, nestes dois anos, junho foi o mês com mais exemplares capturados, como esperado, tendo em conta os padrões da dinâmica sazonal destas espécies. Tendo em conta que os indivíduos pertencentes ao grupo Obsoletus são muito semelhantes, a sua identificação apenas pelo padrão da asa não seria possível. Portanto, para separar estas espécies dentro do grupo Obsoletus é sempre necessário analisar as várias estruturas morfológicas e, por isso, foram detetadas alterações morfológicas. Estas alterações morfológicas podem dever-se ao cruzamento de espécies dentro deste grupo que são muito próximas e/ou ao facto de, dependendo da espécie, de depositarem entre 10 e 675 ovos, o que pode gerar a probabilidade de ocorrerem erros genéticos que podem causar estas malformações anatómicas. Neste projeto podem ser encontradas e descritas características morfológicas anormais, como é o caso de segmentos do palpo fundidos, exemplares com uma ou três espermatecas, em vez de duas funcionais e uma rudimentar. Com este trabalho é reportado pela primeira vez em Portugal um exemplar de C. obsoletusinfértil que possuía apenas uma espermateca e esta não funcional. De forma a compreender a posição taxonómica destes espécimes com malformações anatómicas, foi realizada uma análise molecular, mas depois de várias tentativas não foram obtidos resultados. No total das capturas realizadas neste projeto, as espécies mais prevalentes são as principais vetoras da doença da Língua Azul na Europa, C. imicola e espécies pertencentes ao grupo Obsoletus (C. obsoletus (Meigen, 1818) e C. scoticus (Downes & Kettle, 1952). A distribuição e abundância destas espécies é afetada por fatores abióticos, como a temperatura, a exposição ao vento, entre outros fatores como a proximidade, exposição, densidade e tamanho de potenciais hospedeiros à armadilha, bem como a disponibilidade de habitats ideais ao crescimento das larvas de Culicoides. Existe uma grande preocupação quanto às alterações climáticas e o potencial de permitirem a expansão de vários agentes patogénicos transmitidos por vetores, uma vez que estes são muito sensíveis ao clima. Os resultados deste projeto evidenciam e sustentam que, tendo em conta o impacto económico associado aos agentes patogénicos que transmitem e a constante expansão territorial de novos vetores, é importante realizar estudos entomológicos dos insetos do género Culicoides. Concluindo, é importante ter conhecimento da epidemiologia de uma doença de forma a poder criar as medidas corretas de prevenção, e, além disso, o aumento do conhecimento nesta área permite a consciencialização do perigo deste tipo de doenças. Um conhecimento mais profundo na fauna de Culicoides presente em cada região e as suas preferências quanto a hospedeiros e ambiente é exigida para criar estratégias de controlo que sejam mais eficazmente aplicadas. Para este efeito, deveriam ser realizadas mais monitorizações ao longo do país e estudos onde a variação temporal das capturas, seja semanal ou ao longo de todo o ano, bem como a realização de estudos para se conseguir compreender melhor as anomalias morfológicas encontradas e a sua posição taxonómica, quando comparados com espécies já conhecidas.
Culicoides biting midges (Diptera: Ceratopogonidae) have a major importance in animal and human health since they are vectors of several pathogens, like viruses (Bluetongue, African Horse Sickness and Schmallenberg), filarial nematodes (Mansonella spp.), among others. Bluetongue is an arthropod-transmitted viral disease of domestic and sylvatic ruminants that was recognized and described more than 230 years ago in southern Africa. Bluetongue disease was enzootic throughout tropical and temperate regions of the world until 1998. Then, Bluetongue disease expanded to southern European countries and this spread has been driven by global warming, introduction of infected hosts or infected products from endemic regions that have allowed increased virus persistence, maintenance during the winter and the northward expansion of Culicoides imicola Kieffer, 1913, the main bluetongue virus vector. Female biting midges are responsible for huge economical losses worldwide and, since 2006, new Bluetongue-serotypes have also been reported from countries in Northern and Western Europe, where C. imicola is absent. However, little is known about Culicoides species associated with natural environments, and their role as vector species in wildlife should be investigated since opportunistic host feeding may facilitate virus transfer between wild and domestic hosts and even to humans. The present work is based on Culicoides species captured near sylvatic animals (giraffes, zebras and birds) from Lisbon Zoo, between May 2018 and September 2019, and domestic cattle (cows) from Faculty of Veterinary Medicine, University of Lisbon captured between June 2019 and September 2019 (excluding August because the holiday period). Plus, older collections of cattle from a farm in Leiria District performed in 2010, during the National Entomologic Surveillance Program for Bluetongue disease in mainland Portugal (2005-2013), were used to compare those captured species with the most recent ones. Culicoides were collected with miniature CDC light traps. Then, biting midges were identified by morphological features, in order to understand the variation of Culicoides species in these collection sites. Since knowledge of the blood-feeding behaviour of Culicoides midges is essential in assessing their vectorial competence and determining host preferences clarifies the roles of these species in the epidemiology of different diseases, the main aim of this work was to better understand how the distribution of Culicoides species is between sylvatic animals and domestic cattle. Specific goals include the comparison of Culicoides species captured near: i) sylvatic animals and domestic cattle; ii) three different sylvatic animals: giraffes, zebras and birds; iii) domestic cattle from: Leiria and Lisbon in two different time points and iv) detection and molecular identification of morphological anomalies in Culicoides from Obsoletus group. The captures made between June and September 2019 (excluding August) were used to compare the captures made in Lisbon Zoo and in the Faculty of Veterinary Medicine, where from a total of 135 biting midges collected near sylvatic animals, eight Culicoides species were identified. On the other hand, from 158 Culicoides female specimens collected near domestic cattle, seven were identified. Also, this study showed the abundance of the main BTV vectors in Europe, C. imicola and Obsoletus group species, near sylvatic animals and domestic ruminants. That would support their putative role as bridge vectors for the transmission of the arboviruses between sylvatic animals and domestic cattle and once introduced, consequently, they will spread rapidly over large regions of Europe when appropriate environmental conditions and hosts are present. This is the first study in Portugal of Culicoides fauna captured near sylvatic animals and their comparison with those captured near domestic cattle. The monitorization of Culicoides biting midges in zoo environment is important to avoid potential risk of outbreaks since imported animals could be reservoirs of diseases and zoo is a place where a large number of potential vectors may be present. In Lisbon Zoo, from a total of 1088 Culicoides biting midges, the biggest amount of Culicoides was collected near giraffes, representing 71% of all captures, followed by zebras with 28% and birds with 1%. C. imicola and species from Obsoletus group were the most captured ones. When comparing the 9-year period in farm environments from Leiria in 2010 and Lisbon in 2019, it is important to notice that a drop in captured Culicoides species occurred. Probably this drop happened because of the hot and dry year, that may cause a deficit in the occurrence of favourable conditions for their emergence. However, Obsoletus group species represented in both years the most captured species, with 71% and 81% of all captures in 2010 and 2019, respectively. C. punctatus represented the second most captured species in both years, without significative differences in captures composition. Besides that, in both years, June was clearly the month with more captured specimens, following the characteristic pattern of seasonal dynamic of those species. Since species inside Obsoletus group are very similar, their identification is not possible only by their wing pattern. So, in order to be identified they need to be dissected into different body parts. Through the detailed observation of these midges, it was possible to detect abnormal morphological structures. These abnormal structures may be due to the crossbreeding of close related species or the fact that they deposit 10 to 675 eggs, depending on species, that resulted in genetic errors that could cause morphological modifications. This project gives essential information concerning these aberrant characteristics, including a specimen with only one non-functional spermathecae in C. obsoletus, which was never reported before to the best of our knowledge. Furthermore, a molecular analysis of these specimens was made to understand their taxonomical position but, after several attempts, no results were obtained. Known BTV vectors in Europe, as C. imicola and species from Obsoletus group (C. obsoletus (Meigen, 1818) and C. scoticus (Downes & Kettle, 1952), were the most captured species during this project. Their distribution and abundance are affected by abiotic factors, such as climate, temperature, wind exposure, soil type, surrounding vegetation and other factors, as the potential host proximity and exposure, density and size of hosts nearby the trap and the availability of larval habitats close to the traps. There is a big concern that climate change will lead to expansion of vector-borne diseases, as they are more sensitive to those factors, since these can affect tens of thousands of farms with high financial costs to farmers and countries and causing the death of millions of animals. Thus, such expansion may threaten human health and food security via effects on animal and crop health. Also, this project gives essential information concerning morphological modifications that can be observed in Culicoides biting midges, some of them referred for the first time. Understanding the epidemiology of a disease allow us to take the correct measures to predict and prevent it, as well as enhancing our knowledge about the emergence of other vector-borne pathogens. A deeper knowledge of Culicoides fauna present in each region and their ecological preferences is required, so different control strategies can be applied efficiently.

Master of Science
Department of Animal Sciences and Industry
Micheal J. Brouk
Two studies were conducted that focused on either the accuracy of hand-held near infrared spectrophotometer (NIR) units and two on-farm testing methods compared to conventional 105°C oven drying of corn silage or the use of a starling resistant supplement in total mixed rations (TMR) for lactating dairy cattle. Study 1 evaluated the accuracy of three NIR units (Digi-Star Moisture Tracker, Topcon Agriculture, Fort Atkinson, WI), food dehydrator (FD) (Nesco®, Two Rivers, WI), and a Koster Tester (KT) (Koster Moisture Tester, Inc., Brunswick, OH) to conventional 105°C forced air oven drying. Samples were taken at four Kansas dairy farms and analyzed for DM daily for 20 d. Two calibrations were tested within each NIR unit: NIRu was the DM predicted from the factory-preset calibration, and NIRc was a bias-adjusted DM prediction based on the average difference of oven-dried corn silage and NIRu over the 20-d study. Average oven DM of corn silage was 38.38% ± 0.59 for the 20-d experiment. All three NIRu measurements were lower (P<0.05) than the oven value. While all 3 NIRc predictions were similar (P>0.05) to oven value. KT value was similar (P>0.05) to the oven, while FD value was over estimated DM. (P<0.05). The hand-held NIRS units accurately predicted DM content of the corn silages when the factory preset calibrations were corrected for bias. While the food dehydrator over-estimated the DM of the corn silage and the Koster Tester accurately predicted DM. Study 2 was designed to evaluate the lactation performance of post-peak dairy cattle when using a starling resistant grain supplement. Sixteen prim- and multiparous Holstein cows were housed individually in a tie-stall barn, milked 3x daily, and fed 2x daily. Cows were fed two nutritionally similar diets: 1. TMR with grain in mash form and 2. TMR with grain supplement in a pellet with a 0.953-cm diameter. This study was designed as a single reversal experiment with two 14 d periods with the first 7 d used for an adaptation period and the last 7 d used for data collection in each period. Dry matter intake (DMI), water intake, and milk production was recorded daily. Feed ingredients, TMRS, refusals, and milk samples were collected the last 3 d of each period for analysis. TMRs and refusals were analyzed for particle size distribution with a Penn State Particle Separator. The pelleted supplement had a higher (P<0.05) percentage of DM retained on the 8.0-19.0mm sieve than the mash supplement as the pellet diameter was >8.0mm and could not pass through that sieve. There was no effect of diet (P>0.05) for DMI, feed efficiency, milk component percentage, and protein yield. There was a diet effect (P<0.05) for milk production, fat-corrected milk, energy-corrected milk, solid-corrected milk, and fat yield with lower observed values when cows were fed the pelleted supplement. This leads to the conclusion while a 0.953-cm diameter pellet will reduce starling consumption, it may result in lower milk production of post-peak Holstein cows.

Text in English
Corridor disease is an economically important tick-borne disease of cattle in southern Africa. The disease is caused by Theileria parva and transmitted by the vectors, Rhipicephalus appendiculatus and R. zambeziensis. There is currently no vaccine to protect cattle against T. parva that is permitted in South Africa. To develop recombinant anti-tick vaccines against Corridor disease, comprehensive databases of genes expressed in the tick’s salivary glands are required. Therefore, in Chapters 2 and 3, mRNA from the salivary glands of R. appendiculatus and R. zambeziensis was sequenced and assembled using next generation sequencing technologies. Respectively, 12 761 and 13 584 non-redundant protein sequences were predicted from the sialotranscriptomes of R. appendiculatus and R. zambeziensis and uploaded to public sequence domains. This greatly expanded the number of sequences available for the two vectors, which will be invaluable resources for the selection of vaccine candidates in future. Further, in Chapter 3, differential gene expression analysis in R. zambeziensis revealed dynamic expression of secretory protein transcripts during feeding, suggestive of stringent transcriptional regulation of these proteins. Knowledge of these intricate expression profiles will further assist vaccine development in future. In Chapter 4, comparative sialotranscriptomic analyses were performed between R. appendiculatus and R. zambeziensis. The ticks have previously shown varying vector competence for T. parva and this chapter presents the search for correlates of this variance. Phylogenetic analyses were performed using these and other publically available tick transcriptomes, which indicated that R. appendiculatus and R. zambeziensis are closely related but distinct species. However, significant expression differences were observed between the two ticks, specifically of genes involved in tick immunity or pathogen transmission, signifying potential bioinformatic signatures of vector competence. Furthermore, nearly four thousand putative long non-coding RNAs (lncRNAs) were predicted in each of the two ticks. A large number of these showed differential expression and suggested a potential transcriptional regulatory function of lncRNA in tick blood feeding. LncRNAs are completely unexplored in ticks. Finally, in Chapter 5, concluding remarks are given on the potential impact the R. appendiculatus and R. zambeziensis sialotranscriptomes may have on future vaccine developments and some future research endeavours are discussed.
Life and Consumer Sciences
Ph. D. (Life Sciences)