Avaliação genético-quantitativa de características reprodutivas em éguas da raça puro-sangue inglês
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Data
2004-11
Autores
Taveira, Rodrigo Zaiden [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Poucas informações encontram-se disponíveis acerca dos parâmetros genéticos de características reprodutivas em eqüinos. Sendo assim, conduziu-se um estudo utilizando informações provenientes de 7.278 éguas da raça Puro-Sangue Inglês, sendo 6.327 informações sobre a idade à primeira cobertura (IPC), 5.400 relativas a idade à primeira parição (IPP), 5.473 referentes ao primeiro período de gestação (PPG) e 4.404 relativas ao primeiro intervalo de partos (PIEP). Os dados foram analisados pelo método da máxima verossimilhança restrita, com a utilização do aplicativo MTDFREML para estimação dos componentes de variância e covariância. A idade média à primeira cobertura foi de 4,93 anos, com desvio padrão de 1,45 anos, mínimo de 2,07,anos máximo de 11,94 anos e estimativa de herdabilidade (h2) de 0,19. A idade média à primeira parição foi de 6,01 anos, com desvio padrão de 1,53 anos, mínimo de 3,01anos, máximo de 12,9 anos e estimativa de herdabilidade de 0,38. O primeiro período de gestação médio foi de 337,83 dias, com desvio padrão de 9,47 dias, mínimo de 302 dias, máximo de 396 dias e estimativa de herdabilidade de 0,16. O primeiro intervalo de partos médio foi de 490,18 dias, com desvio padrão de 192,02 dias, mínimo de 303 dias, máximo de 1.095 dias e estimativa de herdabilidade de 0,01. As correlações genéticas encontradas entre a IPC e o IPP, PIEP e PPG foram 1, 0,55 e - 0,13, respectivamente. As correlações genéticas da IPP com PIEP e PPG foram 0,52 e 0,35, respectivamente, enquanto que a correlação genética entre o PIEP e PPG foi de - 0,54. Das características avaliadas a IPP mostrou-se mais interessante para incorporação em programas de seleção que visem melhorar aspectos reprodutivos de eqüinos da raça Puro-Sangue Inglês no Brasil.
There is very little information on the genetic parameters of reproductive traits in equine. With that in mind, a study was conducted using information from 7,278 Thoroughbred mares, of which 6,327 entries were about age at first covering (AFC), 5,400 relating to age at first foaling (AFF), 5,473 relating to first gestation period (FGP) and 4,404 relating to first foaling interval (FFI). The data were analyzed by Maximum Restricted Likelihood, with the application of MTDFREML, to estimate variance and covariance components. Average age at first covering was 4.93 years, with a standard deviation of 1.45 years, minimum of 2.07 years, maximum of 11.94 years and heritability estimate (h2) of 0.19. Average age at first foaling was 6.01 years, with a standard deviation of 1.53 years, minimum of 3.01 years, maximum of 12.9 years and estimative of heritability of 0.38. The first average gestation period was 337.83 days, with a standard deviation of 9.47 days, minimum of 302 days, maximum of 396 days and estimative of heritability of 0.16. First foaling interval was 490.18 days, with a standard deviation of 192.02 days and minimum of 303 days, maximum of 1,095 days and estimative of hereditability of 0.01. Genetic correlations found between AFC and AFF, FFI and FGP were 1, 0.55 and - 0.13, respectively. Genetic correlations of AFF with FFI and FGP were 0.52 and 0.35, respectively, whereas the genetic correlation between FFI and FGP was - 0. 54. Among the evaluated traits, AFF was shown to be the most interesting to incorporate in selection programs whose aim is to improve reproductive traits in Thoroughbred horses in Brazil.
There is very little information on the genetic parameters of reproductive traits in equine. With that in mind, a study was conducted using information from 7,278 Thoroughbred mares, of which 6,327 entries were about age at first covering (AFC), 5,400 relating to age at first foaling (AFF), 5,473 relating to first gestation period (FGP) and 4,404 relating to first foaling interval (FFI). The data were analyzed by Maximum Restricted Likelihood, with the application of MTDFREML, to estimate variance and covariance components. Average age at first covering was 4.93 years, with a standard deviation of 1.45 years, minimum of 2.07 years, maximum of 11.94 years and heritability estimate (h2) of 0.19. Average age at first foaling was 6.01 years, with a standard deviation of 1.53 years, minimum of 3.01 years, maximum of 12.9 years and estimative of heritability of 0.38. The first average gestation period was 337.83 days, with a standard deviation of 9.47 days, minimum of 302 days, maximum of 396 days and estimative of heritability of 0.16. First foaling interval was 490.18 days, with a standard deviation of 192.02 days and minimum of 303 days, maximum of 1,095 days and estimative of hereditability of 0.01. Genetic correlations found between AFC and AFF, FFI and FGP were 1, 0.55 and - 0.13, respectively. Genetic correlations of AFF with FFI and FGP were 0.52 and 0.35, respectively, whereas the genetic correlation between FFI and FGP was - 0. 54. Among the evaluated traits, AFF was shown to be the most interesting to incorporate in selection programs whose aim is to improve reproductive traits in Thoroughbred horses in Brazil.
Descrição
Palavras-chave
Cavalos de corrida, Cavalo - Reprodução, Equino - Reprodução animal, Equino - Genética, Parâmetros genéticos, Equine - Reproduction, Genetic parameters
Como citar
TAVEIRA, Rodrigo Zaiden. Avaliação genético-quantitativa de características reprodutivas em éguas da raça puro-sangue inglês. 2004. v, 71 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, 2004.