Sabiia Seb
        Busca avançada

Botão Atualizar

Botão Atualizar

Registro completo
Provedor de dados:  R. Bras. Zootec.
País:  Brazil
Título:  Genetic evolution of milk yield, udder morphology and behavior in Gir dairy cattle
Autores:  Fernandes,André Rabelo
Faro,Lenira El
Vercesi Filho,Anibal Eugênio
Machado,Carlos Henrique Cavallari
Barbero,Leandro Martins
Bittar,Eustáquio Resende
Igarasi,Mauricio Scoton
Data:  2019-01-01
Ano:  2019
Palavras-chave:  Linear traits
Mammary system
Teat morphology
Udder attachment
Resumo:  ABSTRACT The objective of this study was to analyze the genetic evolution of milk production, udder morphology, and animal behavior of Gir dairy cattle. Data were obtained on the predicted breeding values for milk yield of 60,226 cows born from 1968 to 2015 and standardized predicted breeding values for udder conformation and milking behavior of 7,635 cows born from 1987 to 2015. The influence of tested bulls on genetic trends was discussed, with special focus on the period after 1993, the year when the predicted breeding values of the first group of tested bulls were released. The traits of interest were 305-d milk yield, fore udder attachment, rear udder height, rear udder width, teat length, teat thickness, ease of milking, and reactivity. Significant genetic evolution was observed for 305-d milk yield, with increasing annual growth observed from 1993, as the number of cows sired by the best proven bulls increased. Before 1993, no genetic evolution was observed for any of the studied traits. From 1993 onward, all traits showed genetic gains, except fore udder attachment. The use of genetically-tested bulls since 1993 has led to important genetic gains in the Brazilian Dairy Gir population. Before the identification of genetically superior bulls began, many traits showed no improvement. Selection for milk yield has modified the conformation traits of the Gir mammary system. The longevity of the mammary glands of high-yield cows may be impaired due to poor fore udder attachment. Regarding behavioral traits, this population has evolved to less-reactive animals that are easier to milk.
Tipo:  Info:eu-repo/semantics/article
Idioma:  Inglês
Editor:  Sociedade Brasileira de Zootecnia
Relação:  10.1590/rbz4820180056
Formato:  text/html
Fonte:  Revista Brasileira de Zootecnia v.48 2019
Direitos:  info:eu-repo/semantics/openAccess

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC:

Valid HTML 4.01 Transitional