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Estimation of genetic parameters for udder type traits in the first lactation of Iranian dairy Holstein cattle

Abbas Mikhchi1, Mojtaba Hosseinpour Mashhadi2 and Ghobad Asgari Jafarabadi3

1Department of Animal Science, Science and Research Branch, Islamic Azad University, Tehran, Iran; 2Department of Animal Science, Mashhad Branch, Islamic Azad University, Mashhad, Iran; 3Department of Animal Science, Varamin-Pishva Branch, Islamic Azad University, Varamin, Tehran, Iran

 
Abstract

The objective of this study was to estimate genetic parameters of 8 udder type traits in the first lactation of Holstein dairy cows. The data set consisted of records of 2325 Holstein cows from 1998 to 2011. This data was obtained from Agricultural-Jihad Organization in Khorasan Razavi Province (Northeast of Iran). Traits, all scored on 1 to 9 point scale, were fore udder attachment, udder depth, suspensory ligament, teat length, front teat placement, rear teat position.Genetic parameters were estimated using univariate and bivariate analysis by Wombat software. The models included fixed effects of herd, year, season of calving and the random effect of animal. Heritability estimates obtained from univariate analysis were similar to those obtained from bivariate analysis. Heritability ranged from (0.03) to (0.32) for suspensory ligament and udder depth respectively. Genetic correlations among the udder type traits ranged from (-0.54) to (0.99) for (udder depth and teat length) and (suspensory ligament and udder depth) respectively. Corresponding phenotypic correlations for most pairs of traits were similar in direction but smaller in magnitude than the genetic correlations. Estimated parameters for udder type traits will be used to update the selection index of Holstein dairy cattle.

Keywords: Genetic correlations, Heritability, Iranian Holstein dairy cattle, Udder type traits
 
To cite this article: A Mikhchi, MH Mashhadi and GA Jafarabadi, 2013. Estimation of genetic parameters for udder type traits in the first lactation of Iranian dairy Holstein cattle. Res. Opin. Anim. Vet. Sci., 3(12), 457-461.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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