Estimation of breeding values for dairy cattle using test-day milk yields
Küçük Resim Yok
Tarih
2003
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Scientific Technical Research Council Turkey-Tubitak
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The objectives of this study were to estimate genetic parameters and breeding values for test-day (TD) and 305-day milk yields, and to compare the results from TD and 305-day analyses. The data comprised 10,822 TD records from 1103 first lactations of Holstein cows from state farms in the western part of Turkey. Additive genetic, residual and permanent environmental variances, heritabilities and breeding values for 305-day and TD milk yields were estimated by the REML method using animal models. The heritability estimate (0.11) of TD milk yields was lower than the corresponding estimate (0.25) for 305-day milk yields. The product-moment correlations (greater than or equal to 0.97) show that estimated breeding values (EBVs) for TD milk yields are closely correlated with EBVs for 305-day milk yields. Spearman and Kendall rank correlations between rankings of animals for EBVs for TD and 305-day milk yields were also high (greater than or equal to0.97 and greater than or equal to0.86, respectively). Shifts in rank for various top lists of cows and sires ranked by their EBVs for 305-day and TD milk yields show that more extreme changes in ranks occurred in cows than in sires. TD milk yields could be used instead of 305-day milk yield for the genetic evaluation of dairy cattle. Furthermore, using TD yields for genetic evaluations offers more advantages.
Açıklama
Anahtar Kelimeler
dairy cattle, breeding value, test-day milk yields, test-day model
Kaynak
Turkish Journal of Veterinary & Animal Sciences
WoS Q Değeri
Q4
Scopus Q Değeri
Q3
Cilt
27
Sayı
2
