Análise de pedigree e estimativas de parâmetros genéticos para características de importância econômica em bovinos Tabapuã
Carregando...
Arquivos
Data
2014-07-17
Autores
Bernardes, Priscila Arrigucci [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A raça de bovinos de corte Tabapuã possui características desejáveis para as condições tropicais de produção como rusticidade e adaptabilidade. No entanto, é uma raça de formação recente e existem poucos estudos da estrutura populacional, variabilidade genética, endogamia e estimativas de parâmetros genéticos para características de interesse econômico. Este trabalho teve dois objetivos principais. O primeiro foi avaliar e descrever a estrutura populacional da raça Tabapuã e a relação linear de classes de coeficiente de endogamia com as médias dos valores fenotípicos de peso ao desmame ajustado para 210 dias de idade (P210), idade ao primeiro parto (IPP), intervalo de partos médio (IPM), primeiro intervalo de partos (IP1), segundo intervalo de partos (IP2) e produtividade acumulada (PAC). O segundo objetivo foi estimar parâmetros genéticos, tendências genéticas e eficiência relativa de seleção para P210, IPP, IPM, IP1 e PAC em uma população de bovinos Tabapuã. Foram utilizados registros fenotípicos de 7.340 vacas da raça Tabapuã, pertencentes ao Programa de Melhoramento Genético da Raça Tabapuã (PMGRT) mantido pela Associação Nacional de Criadores e Pesquisadores (ANCP). O arquivo de pedigree continha 15.241 animais. A análise de estrutura populacional foi realizada por meio do programa ENDOG. As estimativas dos parâmetros genéticos foram obtidas pelo método de máxima verossimilhança restrita, utilizando modelo animal multicaracterística. O teste de razão de verossimilhança foi utilizado para definir os efeitos aleatórios para análise de P210. O modelo animal de P210 incluiu os efeitos aleatórios genético aditivo materno e de ambiente permanente, além do efeito genético aditivo direto e do efeito residual e efeitos fixos. Para IPP, IPM, IP1 e PAC consideraram-se apenas o efeito aleatório genético aditivo direto, efeito aleatório residual e efeitos fixos. As tendências genéticas ...
Tabapuã is a rustic beef cattle breed that is highly adapted to tropical environmental conditions. Due Tabapuã recent origin, there are only a few studies about population structure and genetic parameters. Thus, this study had two main objectives. The first was to evaluate the population structure and relationship of inbreeding coefficient and the phenotype of weaning weight adjusted at 210 days of age (W210), age at first calving (AFC), average of calving interval (ACI), first calving interval (CI1), second calving interval (CI2), and accumulated productivity (ACP). The second was to estimate genetic parameters, genetic trends and relative efficiency of selection for W210, AFC, ACI, CI1, and ACP in Tabapuã beef cattle. We used pedigree information of 15,241 animals and phenotypic information of 7,340 Tabapuã cows included in the Brazilian Tabapuã Breeding Program. Analysis of population structure was performed using ENDOG software. Estimates of genetic parameters were obtained by restricted maximum likelihood method, fitting a multiple-trait animal model. The likelihood ratio test was used to define the random effects for W210 analysis. For W210 the maternal genetic, permanent environmental, additive genetic, and residual effects were included in model; while only the additive genetic and residual effects were included for AFC, ACI, CI1, and ACP. Genetic trends were calculated from a linear regression of predicted breeding value on birth year. Average pedigree completeness was 47.99% for 6 last generations. Complete, maximum and equivalent generations were 5, 16 and 6.66, respectively. Effective number of founders and ancestors was equal to 124 and 110, respectively, and the ratio between both was 1.13. The average inbreeding coefficient was equal to 0.0072.The average inbreeding coefficient as well as the average relatedness and the percentage of number of inbred animals increased across generation. However, it was observed ...
Tabapuã is a rustic beef cattle breed that is highly adapted to tropical environmental conditions. Due Tabapuã recent origin, there are only a few studies about population structure and genetic parameters. Thus, this study had two main objectives. The first was to evaluate the population structure and relationship of inbreeding coefficient and the phenotype of weaning weight adjusted at 210 days of age (W210), age at first calving (AFC), average of calving interval (ACI), first calving interval (CI1), second calving interval (CI2), and accumulated productivity (ACP). The second was to estimate genetic parameters, genetic trends and relative efficiency of selection for W210, AFC, ACI, CI1, and ACP in Tabapuã beef cattle. We used pedigree information of 15,241 animals and phenotypic information of 7,340 Tabapuã cows included in the Brazilian Tabapuã Breeding Program. Analysis of population structure was performed using ENDOG software. Estimates of genetic parameters were obtained by restricted maximum likelihood method, fitting a multiple-trait animal model. The likelihood ratio test was used to define the random effects for W210 analysis. For W210 the maternal genetic, permanent environmental, additive genetic, and residual effects were included in model; while only the additive genetic and residual effects were included for AFC, ACI, CI1, and ACP. Genetic trends were calculated from a linear regression of predicted breeding value on birth year. Average pedigree completeness was 47.99% for 6 last generations. Complete, maximum and equivalent generations were 5, 16 and 6.66, respectively. Effective number of founders and ancestors was equal to 124 and 110, respectively, and the ratio between both was 1.13. The average inbreeding coefficient was equal to 0.0072.The average inbreeding coefficient as well as the average relatedness and the percentage of number of inbred animals increased across generation. However, it was observed ...
Descrição
Palavras-chave
Bovino de corte, Tabapuã (Zebu), Genetica animal, Bovino - Reprodução, Animais - População, Animal genetics
Como citar
BERNARDES, Priscila Arrigucci. Análise de pedigree e estimativas de parâmetros genéticos para características de importância econômica em bovinos Tabapuã. 2014. vi, 73 p. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Ciências Agrárias e Veterinárias, 2014.