Genetic evaluation of sires due to stillbirth of their daughters in a herd of Holstein cows

	Genetic evaluation of sires due to stillbirth of their daughters in a herd of Holstein cows
journal of kerbala university
Article 1, Volume 3, Issue 3, 2007, Pages 320-329 PDF (0 K)
Abstract
A total of 9691 records of borns belonged to 3076 Holstein cow and 58 sire were analyzed over period from 1990 to 1999 , at Nasr Dairy Cattle Station. The aim of the research is to study the effect of some fixed factors on stillbirth and to estimate heritability ,phenotypic trend and best linear unbiased prediction for sires due to the stillbirth of their daughters.Data was analayzed using General Linear Model within the SAS program to study the effects of some fixed factors ( season and year of calving, parity sex of calf )on the stillbirth. Component 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 means for stillbirth was 11.19% in primiparous , 8.69% in multiparous and 9.49% in both of them.The effect of all fixed factors were significant (P < 0.01 ) .Heritability of direct effects estimated for primiparous and multiparous and both of them were 0.03, 0.007, 0.02 respectively ,whereas the corresponding estimates for heritability of maternal effects were 0.04 .0.02 ,0.03 respectively. Phenotypic trend of stillbirth in primiparous was positive and non significant (0.19% / year) whereas nagative and non significant ( P < 0.05 ) (- 0.11%/year) in multiparous and in both of them (- 0.07%/year) , as well as that Minimum and maximum BLUP of sires due to stillbirth ratio were 7.33 and 10.33% respectively.

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