Data/hora: 04/06/2024 15:22:40

Provedor de dados: 	96	
País: 	Brazil	
Título: 	Incorporation of lactations with non-conventional drying-off causes in genetic evaluation of Gyr dairy cattle	
Autores: 	Reis Filho,João Cruz; Toral,Fábio Luiz Buranelo; Verneque,Rui da Silva; Vercesi Filho,Anibal Eugênio; Torres,Robledo de Almeida; Euclydes,Ricardo Frederico.	
Data: 	2012-09-01	
Ano: 	2012	
Palavras-chave: 	Autoregressive; Consistency; Database; Environmental; Genetic parameters.	
Resumo: 	Test-day records of milk yields from the first three lactations were used to verify consequences of incorporation of lactation with non-conventional drying-off causes in genetic evaluation of Gyr dairy cattle. The first file (File1) was composed of test-day records of lactations with conventional drying-off causes. In the second file (File2), the test-day records of lactations with non-conventional drying-off causes were included, such as drying-off by death or separation of the calf, disease, death or sale of cow, and removal of cow from milking control. Data were analyzed by mixed models, using an autoregressive process to adjust the random effects of long-term and short-term environment. The inclusion of test-day records from lactations with non-conventional drying-off causes increased the number of controls by 12% and the number of cows by 18%, and it generated an increase in the estimates of variance components. These results impacted estimates of heritability, calculated at 0.32, 0.28 and 0.26 for the first, second and third lactations in File1, respectively, while in File2 they were 0.34, 0.30 and 0.28 to the same lactation order. The estimated accuracy of predicted breeding values in File2 were higher in relation to File1, but the Pearson and Spearman correlations between predicted breeding values of animals in the two files were high. Lactations with non-conventional drying-off causes can be incorporated to the routines of genetic evaluation of Gyr dairy cattle, because they provide higher estimates of heritability and accuracy of breeding values, which could raise expectations of genetic gains with selection.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000900008	
Editor: 	Sociedade Brasileira de Zootecnia	
Relação: 	10.1590/S1516-35982012000900008	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Zootecnia  v.41 n.9 2012	
Fonte: 	info:eu-repo/semantics/openAccess