The Effect of Some Factors on Stillbirth in Primiparous and Multiparous Holstein Cattle in Iraq
Abstract
A total of 9691 records of calves belonged to 3076 Holstein cows and 58 sires were
analyzed from 1995 to 1999 , at Nasr Dairy Cattle Station. The aim of the research is to evaluate
sires geneticelly by using best linear unbiased prediction ( BLUP) according to the stillbirths of
their daughters after adjusting for fixed effects and to estimate heritability, phenotypic trend for
the mentioned trait. Data were analayzed by using General Linear Model within SAS program to
investigate the effectof some fixed factors ( season and year of calving, parity sex of calf ) on the
stillbirths. Components of variance for the random effects in the employed mixed model were
estimated by the Minimum Variance Quadratic Unbiased Estimation (MIVQUE) method. The
Harvey program was also used to estimate BLUP values for sires. The overall mean of stillbirths
was 11.19% in primiparous, 8.69% in multiparous and 9.49% in both of them.The effect of all
fixed factors was significant (P < 0.01 ) . Heritability of direct effect estimated for stillbirth rates in
primiparous and multiparous and in both of them were 0.03 , 0.007 , 0.02 respectively ,whereas
corresponding estimates of heritability of maternal effects were 0.04 .0.02 ,0.03 respectively .
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