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A pecuária de corte brasileira tem sofrido grande pressão devido às questões ambientais, às exigências dos mercados consumidores por carne de qualidade e rígidos padrões sanitários. Esses fatores aumentam a importância da melhoria da eficiência produtiva da pecuária de corte. A proposta do presente trabalho foi avaliar o efeito da inclusão dos valores genéticos moleculares, de um painel de marcadores genéticos comerciais (Perfil IGENITY® Nelore V3) na seleção de animais da raça Nelore. Foram utilizados dados de 9.749 animais da raça Nelore mensurados para área de olho de lombo, espessura de gordura subcutânea e espessura de gordura na picanha e 39.687 animais na matriz de parentesco. Dois modelos de análise foram utilizados. O modelo de análise uni-característica em que apenas os parâmetros genéticos do fenótipo foram estimados e o modelo bi-característica em que os valores genéticos moleculares de 3.033 animais foram incluídos como característica correlacionada. A inclusão dos valores genéticos moleculares no modelo aumentou as acurácias das estimativas dos valores genéticos preditos dos animais genotipados, principalmente dos machos jovens. As analises dos conflitos de seleção demonstraram maiores divergências nos touros e machos jovens que tiveram seus genótipos definidos. A taxa de ganho genético anual com a inclusão dos valores genéticos moleculares no modelo foi aumentada em 2,4% para área de olho de lombo, 0,9% para espessura de gordura subcutânea e 1,9% para espessura de gordura na picanha. Esses resultados demonstram que a utilização dos valores genéticos moleculares , mesmo quando oriundos de painéis de marcadores de DNA de baixa densidade, pode contribuir na seleção de animais superior mérito genético e, além de promover aumento nos ganhos genéticos dos programas de melhoramento genético da raça Nelore. / The Brazilian beef cattle chain is suffering a huge pressure due to environmental issues, the demand of consumer markets for meat quality and strict sanitary standards of the international market. These factors increase the importance of improving productive efficiency of beef cattle. The proposal of this study was to evaluate the effect of inclusion of the molecular breeding values of a commercial panel of genetic markers (Nellore Profile IGENITY® V3) in the genetic selection of Nellore cattle. Data of 9,749 animals measured for ribeye area, fat thickness and rump fat thickness were used in this study, with a relationship matrix compound of 39,687 animals. Two models of analysis were performed. Single trait model was performed only for each observed phenotypes and two-trait model was performed phenotypes and molecular breeding values of 3,033 animals as a correlated trait. The inclusion of molecular information in genetic evaluation provided increases on the accuracies of predicted breeding values of genotyped animals and, mainly, for replacement young bulls. The divergences of selection for 20% best animals classified by 1-trait breeding values and 2-trait breeding values demonstrated highest divergence for sires and replacement young bulls. The genetic change rate on the 2-trait model increased 2,4% for ribeye area, 0,9 for fat thickness and 1,9% for rump fat thickness. These results demonstrated that the inclusion of molecular breeding values, even when estimated from low density genetic markers panels, on animal breeding evaluations can contribute on the selection of best genetic merit animals and increase of genetic change rate on animal breeding programs for Nellore cattle.

A estratégia de criação de grupos genéticos aditivos é uma técnica que permite que animais de paternidade desconhecida tenham seus valores genéticos preditos de forma mais adequada quando incluídos em programas de melhoramento genético. O modo como esses grupos são formados é ainda arbitrário, o que torna importante o estudo de metodologias de formação de grupos genéticos aditivos (GG) visando a uma estrutura apropriada para as avaliações dos rebanhos em programas de melhoramento genético animal. O objetivo do trabalho foi definir a estrutura de grupo genético adequada às avaliações genéticas, comparando-as em relação às mudanças efetivas na eficiência do processo seletivo dos animais com paternidade desconhecida. As características estudadas foram: peso ao desmame, peso ao sobreano, ganho de peso pós-desmama, perímetro escrotal ao sobreano e escore visual de musculosidade ao sobreano. Três cenários foram simulados a partir de um banco de dados composto apenas por animais com pedigree completo (grupo controle). O primeiro teve 30% dos animais com identificação de pai apagada, o segundo 50% e um terceiro com 70%. As estratégias de formação de GG foram: a fazenda de nascimento do animal com paternidade desconhecida; o ano de nascimento (SAFRA) e a concatenação de ano de nascimento e fazenda de nascimento (FAZSAFRA). Os componentes de variância foram calculados para o banco controle pelo software VCE e os valores genéticos foram preditos pelo software PEST, utilizando duas estruturas de modelo animal que se diferenciaram pela inclusão ou não do efeito fixo de GG. A definição da estrutura de grupo genético aditivo adequado à avaliação genética dos animais foi baseada na eficiência de seleção e na comparação entre os valores genéticos preditos quanto aos seus valores absolutos e quanto à classificação dos animais, sendo que animais do grupo controle foram assumidos como tendo o máximo em resposta à seleção genética. Os resultados demonstraram que os grupos genéticos aditivos proporcionam uma melhora na predição genética dos animais com paternidade desconhecida. As estratégias que proporcionaram valores mais próximos aos do grupo controle foram SAFRA e FAZSAFRA e, mesmo com similaridade de valores, a estratégia SAFRA foi superior na seleção dos melhores animais. / The structure of genetic groups is a technique that allows that animals with unknown paternity be included in breeding programs. The ways these groups are formed are still arbitrary, which makes it important to study formation methodologies of genetic groups aiming an appropriate framework for the evaluation of livestock in animal breeding programs. Therefore, the aim of this study was to define the structure of genetic group suited to genetic evaluations, comparing them regarding changes in the effective efficiency of the process of animals with unknown parentage. The characteristics studied were: weaning weight, post-weaning weight, post-weaning weight gain, scrotal circumference at 18 months of age and visual muscularity score at 18 months of age. Three scenarios were simulated from a database consisting only of complete pedigree animals (control group). The first had 30% of animals with identification of father off, the second with 50% and a third with 70%. The training strategies additive genetic groups were: the farm of birth of the animal with unknown parentage; birth year (SAFRA) and the concatenation of year of birth and birth farm (FAZSAFRA). The variance components were calculated for the data bank control program by VCE and breeding values were predicted using PEST software, with two structures of animal models that differ by the inclusion or not of the fixed effect of additive genetic group. The definition of the structure of genetic group suitable for genetic evaluation of animals was based on the efficiency of selection and comparison of estimated breeding values to the \"control\" breeding values and the classification of animals, while control animals were assumed to have the maximum response to selection whereas the choice of any other group of animals results in a reduction thereof. The results demonstrated that the additives genetic groups provide an improvement in the genetic prediction of animals with unknown paternity. Strategies that provided values closer to those of the control group were SAFRA and FAZSAFRA and even with similarity values, strategy SAFRA was superior in selecting the best animals.

The objectives of this study were to 1) evaluate marker associations for genomic regions of interest and significant ontology terms, 2) evaluate and compare 4 models for their efficacy in predicting genetic merit, 3) evaluate and compare the impact of using breed-of-origin genotypes in a Bayesian prediction model, and 4) evaluate the effects of data partitioning using family structure on predictions. Nellore-Angus F2, F3 and half-sibling calves were used with records for overall temperament at weaning (OTW; a subjective scoring system; n = 769) and Warner-Bratzler shear force (WBSF; a measure of tenderness; n = 389). After filtering, 34,913 markers were available for use. Bayesian methods employed were BayesB (using ̂) and BayesC (using π = 0 and ̂) in GenSel software, where, after estimation, π ̂ = 0.995 or 0.997 for WBSF or OTW, respectively. No regions associated with either trait were found using π ̂, but when π = 0 associated regions were identified (37 and 147 regions for OTW and WBSF, respectively). Comparison of genomic estimated breeding values from these 3 Bayesian models to an animal model showed that BayesC procedures (using ̂) had the highest accuracy for both traits, but that BayesB had the lowest indication of bias in either case. Using a subset of the population (n = 440), genotypes based on the breed in which the alleles originated from (i.e., breed-of-origin genotypes) were assigned to markers mapped to autosomes (n = 34,449), and incorporated into prediction analyses using BayesB (π ̂ = 0.997) with or without nucleotide-based genotypes. In either case, there was an increase in accuracy when breed-of-origin genotypes were incorporated into prediction analyses. Data partitions based on family structure resulted in 13 distinct training and validations groups. Relationship of individuals in the training with validation individuals did have an impact in some cases, but not all. There was poor prediction of genomic estimated breeding values for individuals in the validation population using BayesB methods, but performed better in all cases than breeding values generated using an animal model. Future studies incorporating breed-of-origin genotypes are of interest to determine if accuracy is improved in these groups.

The aim of this thesis was to evaluate the chosen effects of control of performance on the growth of calves in the most common meat breeds of the South Bohemian region (Aberdeen Angus, Charolais, Limousine, Beef Simmental) involved in the monitoring of performance of beef cattle during the period 2009 - 2014. The aim of this thesis was to evaluate what influences affect the weight of beef calves during their rearing. When comparing the average weight of calves according to breed, the highest weight at birth were (42.37 kg), at 120 days (191.32 kg), at 210 days (307.65 kg) and at 365 days (503.53 kg) with the Charolais breed. When examining the influence of year of calving at the birth weight at 120, 210, and 365 days, it was found that calves of Limousine breed clearly reached the highest weight in 2012 in all age categories. In determining the effect of month of calving for the birth weight at 120 and 210 days of age, the best months are December to March for Aberdeen Angus and April was the best month for calving for Beef Simmental. The period of calving is going from winter until spring months. Aberdeen Angus cows up to the fifth calving make up 73.29 % of the herd. When examining the influence of calving order to calves weighing at 120, 210 and 365 days of age, the worst of all breeds are calves from the first calving. At 120 and 210 days of age, Aberdeen Angus calves were at the highest weight with the 6th calving, Limousine breed were at the highest weight of calves with the 9th calving. At 365 days of age, Aberdeen Angus calves had the highest weight with the third calving. Rearing management breed is clearly the best with breeders who participate in national exhibitions and produce bulls and heifers. Relative breeding values of the Fathers for Direct effect - growth (Peru) and relative breeding values for maternal maternal effect - growth (Meru), have verifiable affect on the weight of calves

The aim of this work was to compile a summary of the information provided to the public breeders by the five warm-blood horse breeding organizations in the Czech Republic. Mentioned horses are used for sporting purposes. A similar report was done on the extent and quality of information provided to the public breeders in neighboring European countries. We had prepared a proposal for a system that would provide the necessary information for effective breeding work . In the Czech Republic there is a system for collecting information about the population of horses. However, it is necessary to evaluate and publish information in an understandable form to breeders. As a basis for the preparation of tabular overview of the number of warm-blood horses bred in the Czech Republic, were collected the data from the Central horse register website and data from yearbooks and websites of individual breeders associations. Data were collected for the period of 2006 - 2013. In this thesis the processed data covers these breeds: Czech warmblood, Slovak warmblood, Moravian warmblood , Kinsky horse and Czech Traken. We have suggested the system, configuration and method for disclosure of the breeding information for warm-blood horse breeders and there is also recommended the annual frequency. As a model stallion was chosen Dutch warmblood Great Pleasure and we have created an information portfolio of this stallion. The system of the published information includes identification of the horse, pedigree, exterior evaluation, the results of his performance, comparing features and characteristics of the offspring population and the average breeding value estimation for exterior and performance. An important point is to make the overview of births and evaluated offspring. The proposed system should allow the improvement of the current breeding process and provide objective information to breeders for the right breeding decisions.

A pecuária de corte brasileira tem sofrido grande pressão devido às questões ambientais, às exigências dos mercados consumidores por carne de qualidade e rígidos padrões sanitários. Esses fatores aumentam a importância da melhoria da eficiência produtiva da pecuária de corte. A proposta do presente trabalho foi avaliar o efeito da inclusão dos valores genéticos moleculares, de um painel de marcadores genéticos comerciais (Perfil IGENITY® Nelore V3) na seleção de animais da raça Nelore. Foram utilizados dados de 9.749 animais da raça Nelore mensurados para área de olho de lombo, espessura de gordura subcutânea e espessura de gordura na picanha e 39.687 animais na matriz de parentesco. Dois modelos de análise foram utilizados. O modelo de análise uni-característica em que apenas os parâmetros genéticos do fenótipo foram estimados e o modelo bi-característica em que os valores genéticos moleculares de 3.033 animais foram incluídos como característica correlacionada. A inclusão dos valores genéticos moleculares no modelo aumentou as acurácias das estimativas dos valores genéticos preditos dos animais genotipados, principalmente dos machos jovens. As analises dos conflitos de seleção demonstraram maiores divergências nos touros e machos jovens que tiveram seus genótipos definidos. A taxa de ganho genético anual com a inclusão dos valores genéticos moleculares no modelo foi aumentada em 2,4% para área de olho de lombo, 0,9% para espessura de gordura subcutânea e 1,9% para espessura de gordura na picanha. Esses resultados demonstram que a utilização dos valores genéticos moleculares , mesmo quando oriundos de painéis de marcadores de DNA de baixa densidade, pode contribuir na seleção de animais superior mérito genético e, além de promover aumento nos ganhos genéticos dos programas de melhoramento genético da raça Nelore. / The Brazilian beef cattle chain is suffering a huge pressure due to environmental issues, the demand of consumer markets for meat quality and strict sanitary standards of the international market. These factors increase the importance of improving productive efficiency of beef cattle. The proposal of this study was to evaluate the effect of inclusion of the molecular breeding values of a commercial panel of genetic markers (Nellore Profile IGENITY® V3) in the genetic selection of Nellore cattle. Data of 9,749 animals measured for ribeye area, fat thickness and rump fat thickness were used in this study, with a relationship matrix compound of 39,687 animals. Two models of analysis were performed. Single trait model was performed only for each observed phenotypes and two-trait model was performed phenotypes and molecular breeding values of 3,033 animals as a correlated trait. The inclusion of molecular information in genetic evaluation provided increases on the accuracies of predicted breeding values of genotyped animals and, mainly, for replacement young bulls. The divergences of selection for 20% best animals classified by 1-trait breeding values and 2-trait breeding values demonstrated highest divergence for sires and replacement young bulls. The genetic change rate on the 2-trait model increased 2,4% for ribeye area, 0,9 for fat thickness and 1,9% for rump fat thickness. These results demonstrated that the inclusion of molecular breeding values, even when estimated from low density genetic markers panels, on animal breeding evaluations can contribute on the selection of best genetic merit animals and increase of genetic change rate on animal breeding programs for Nellore cattle.

A estratégia de criação de grupos genéticos aditivos é uma técnica que permite que animais de paternidade desconhecida tenham seus valores genéticos preditos de forma mais adequada quando incluídos em programas de melhoramento genético. O modo como esses grupos são formados é ainda arbitrário, o que torna importante o estudo de metodologias de formação de grupos genéticos aditivos (GG) visando a uma estrutura apropriada para as avaliações dos rebanhos em programas de melhoramento genético animal. O objetivo do trabalho foi definir a estrutura de grupo genético adequada às avaliações genéticas, comparando-as em relação às mudanças efetivas na eficiência do processo seletivo dos animais com paternidade desconhecida. As características estudadas foram: peso ao desmame, peso ao sobreano, ganho de peso pós-desmama, perímetro escrotal ao sobreano e escore visual de musculosidade ao sobreano. Três cenários foram simulados a partir de um banco de dados composto apenas por animais com pedigree completo (grupo controle). O primeiro teve 30% dos animais com identificação de pai apagada, o segundo 50% e um terceiro com 70%. As estratégias de formação de GG foram: a fazenda de nascimento do animal com paternidade desconhecida; o ano de nascimento (SAFRA) e a concatenação de ano de nascimento e fazenda de nascimento (FAZSAFRA). Os componentes de variância foram calculados para o banco controle pelo software VCE e os valores genéticos foram preditos pelo software PEST, utilizando duas estruturas de modelo animal que se diferenciaram pela inclusão ou não do efeito fixo de GG. A definição da estrutura de grupo genético aditivo adequado à avaliação genética dos animais foi baseada na eficiência de seleção e na comparação entre os valores genéticos preditos quanto aos seus valores absolutos e quanto à classificação dos animais, sendo que animais do grupo controle foram assumidos como tendo o máximo em resposta à seleção genética. Os resultados demonstraram que os grupos genéticos aditivos proporcionam uma melhora na predição genética dos animais com paternidade desconhecida. As estratégias que proporcionaram valores mais próximos aos do grupo controle foram SAFRA e FAZSAFRA e, mesmo com similaridade de valores, a estratégia SAFRA foi superior na seleção dos melhores animais. / The structure of genetic groups is a technique that allows that animals with unknown paternity be included in breeding programs. The ways these groups are formed are still arbitrary, which makes it important to study formation methodologies of genetic groups aiming an appropriate framework for the evaluation of livestock in animal breeding programs. Therefore, the aim of this study was to define the structure of genetic group suited to genetic evaluations, comparing them regarding changes in the effective efficiency of the process of animals with unknown parentage. The characteristics studied were: weaning weight, post-weaning weight, post-weaning weight gain, scrotal circumference at 18 months of age and visual muscularity score at 18 months of age. Three scenarios were simulated from a database consisting only of complete pedigree animals (control group). The first had 30% of animals with identification of father off, the second with 50% and a third with 70%. The training strategies additive genetic groups were: the farm of birth of the animal with unknown parentage; birth year (SAFRA) and the concatenation of year of birth and birth farm (FAZSAFRA). The variance components were calculated for the data bank control program by VCE and breeding values were predicted using PEST software, with two structures of animal models that differ by the inclusion or not of the fixed effect of additive genetic group. The definition of the structure of genetic group suitable for genetic evaluation of animals was based on the efficiency of selection and comparison of estimated breeding values to the \"control\" breeding values and the classification of animals, while control animals were assumed to have the maximum response to selection whereas the choice of any other group of animals results in a reduction thereof. The results demonstrated that the additives genetic groups provide an improvement in the genetic prediction of animals with unknown paternity. Strategies that provided values closer to those of the control group were SAFRA and FAZSAFRA and even with similarity values, strategy SAFRA was superior in selecting the best animals.

Thesis (M.Sc. Agriculture (Animal Production)) -- University of Limpopo, 2020 / Stillbirth is a trait of high economic importance in dairy cattle and is increasingly being included in dairy cattle breeding objectives worldwide. In South Africa, however, there is limited information on stillbirth that can be used to improve this trait genetically. Currently, there are no estimated breeding values (EBVs) for any measures of calving performance produced under the national genetic evaluation programme. The current study was, therefore, conducted to assess the incidence of stillbirth and estimate the genetic and environmental influences on maternal effects for stillbirth in South African Holstein cattle, to enable estimation of breeding values for the trait. Data used in the study comprised 13 143 calving records of 7 723 Holstein cows, from 41 herds, participating in the National Dairy Animal Recording and Improvement Scheme during the period 2014 to 2018. Incidence of stillbirth was determined using the PROC FREQ procedure and environmental effects were tested by the General Linear Models (GLM) procedure of Statistical Analysis System (SAS 9.4, 2016). Maternal heritability of stillbirth was estimated by the Restricted Maximum Likelihood (REML) procedure, using the ASReml software (Gilmour et al., 2018). The analyses were carried out using a threshold animal model and a repeatability animal model, where the latter considered stillbirth in different parities as repeated measures of the same trait. Environmental effects significantly influencing stillbirth (p<0.05) were herd-year season of calving, dam parity and calf sex, and these were included in the model for variance component estimation. Estimates of maternal heritability effects from the threshold animal model were 0.12±0.04, 0.15±0.08 and 0.14±0.06 for parities 1 to 3, respectively. The repeatability animal model gave a heritability estimate of 0.09±0.03 and a repeatability of 0.18±0.03. The moderate estimates of maternal heritability indicate scope for reducing incidence of stillbirth by selectively breeding cows that are less genetically predisposed to calving dead calves. Stillbirth in different parities should not be considered as the same trait, as indicated by the low repeatability estimate. Results of the current study estimate genetic parameters that are required to compute accurate estimated breeding values (EBVs) for stillbirth, which will enable South African Holstein farmers to select for reduced stillbirths, thus improving calving performance / National Research Foundation (NRF), University of Limpopo (UL) and Department of Agriculture Forestry and Fisheries (DAFF)

No description available.