Genetic and environmental factors affecting lactation length of dairy goats in Brazil

Authors

  • Heraldo Cesar Gonçalves Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção e Exploração Animal, Botucatu, SP
  • Francisco Stefano Wechsler Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção e Exploração Animal, Botucatu, SP
  • Alcides de Amorim Ramos Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Produção e Exploração Animal, Botucatu, SP

Keywords:

goat milk, heritability, repeatability

Abstract

Environmental effects and genetic parameters were estimated for the lactation length (DL) of dairy goats using two statistical methods, least square (MMQ) and restricted maximun likelihood (REML). The data were 1.336 observations on three breeds (Alpine, Saanen and Toggenburg), collected on seven farms over seven years. The least squares mean and respective standard error was 236.19 ± 9.63 days. On those years when the effect of kidding season on DL was observed, the means of season 3 (beginning of Spring) were lower than at least one of the other two. Farm-breed combination showed a significant effect on DL. Management differences among farmes were more important effects than the differences in breed genetic potential. Maximun DL occurred at the age of 44.07 months. Heritability and repeatability coefficients, as estimated were 0.367 and 0.108 (MMQ) and 0.11 and 0.11 (REML) respectively, evidencing the large environmental influence on this trait. The genetic and phenotypic correlation between milk yield and DL estimated were .81 and .62 (MMQ) and .52 and .60 (REML) respectively.

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Published

2013-11-29

Issue

Section

GENETIC

How to Cite

Genetic and environmental factors affecting lactation length of dairy goats in Brazil. (2013). Bulletin of Animal Husbandry, 59(1), 17-29. http://bia.iz.sp.gov.br/index.php/bia/article/view/1369

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