ESTIMATES OF VARIANCE COMPONENTS TO MATERNAL AND DIRECT EFFECTS FOR SOME GROWTH TRAITS OF HOLSTEIN CATTLE

N.N, AI-Anbari; F.R, AI-Samarai

	ESTIMATES OF VARIANCE COMPONENTS TO MATERNAL AND DIRECT EFFECTS FOR SOME GROWTH TRAITS OF HOLSTEIN CATTLE
The Iraqi Journal of Agricultural Science
Article 1, Volume 38, Issue 2, 2007, Pages 76-86
Authors
AI-Anbari N.N; AI-Samarai F.R
Abstract
". This experiment included 3412 records.of birth weight and 1378 records of weaning weight, gain, daily gain and age at weaning related to 27 sire .through the period from 1993 to 2000, at the Eshaqi dairy cattle station . The purpose was to study genetic evaluation of sires and dams according to their calves birth weight, weaning weight, gain ,daily gain, weaning age before adjusting to some fixed effects and to estimate heritability. The General Linear Model by using SAS (2001) program was used to study the effect of fixed factors ( season and year of birth, parity and sex) on the studied traits. Components of variance for the random effects in the employed mixed model were estimated by the Minimum Variance Quadratic Unbiased Estimation .The Harvey program (1991) was also used to estimate BLUP values for 27 sires and 1164 dams. The effect ofall fixed factors were significant, except parity. The overall means of birth weight, weaning weight ,gain, daily gain and age at weaning were 34.28 kg , 88.58 kg , 53.69 . kg, 438.64 g and 123.46 d , respectively. The heritability of maternal effects of the studied traits were 0.06 , 0.06 ,0.03 ,0.05 and 0.01 , respectively and for direct effects were 0.16 , 0.16 , 0.21 .0.06 and 0.23 , respectively. There was a wide range in BLUP values estimated which reflected the importance of genetic additive variance. This could be used latter via selection methods to improve the mentioned characteristics of Holstein cattle in Iraq.

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