Genetic evaluation of first milk yield and first calving interval  in a herd of Holstein

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

	Genetic evaluation of first milk yield and first calving interval in a herd of Holstein
Journal of Univesity of Thi-Qar
Article 1, Volume 5, Issue 0, 2010, Pages 1-7
Authors
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Abstract
Genetic evaluation of first milk yield and first calving interval in a herd of Holstein F.R.Al-Samarai N.N.Al-Anbari * Veterinary Medicine College – University of Baghdad * * Department of Animal Resources – Agriculture College - University of Baghdad ABSTRACT Data on 944 Holstein cattle maintained at the Nasr Dairy Cattle Station, United Company for Animal Resources Ltd., Al-Soueira ( 50 Km South of Baghdad ) during 1998 – 2004 ,were used to study the influence of various factors on first milk yield and first calving interval . Data was analysed using the General Linear Model ( GLM ) within the SAS program to study the effects of season and year of calving , age at first calving . Components of variance for the random effects were estimated by the Minimum Variance Quadratic Unbiased Estimation procedure ( MIVQUE ) . The results showed that season and year of calving had a significant effect ( P < 0.01 ) on the first milk yield .Whereas season of birth had a significant effect ( P < 0.01 ) on calving interval only. Heritability estimated for first milk yield and calving interval were 0.43 , 0.14 respetively. Best Linear Unbiased Prediction BLUP of 23 sires for first milk yield were ranged from 866.74 to – 1043.05 kg and the crossponding BLUP for calving interval were 166.84 to – 38.55 day. BLUP estimates displayed a wide range among sires included in the current study, therefore they are of utmost importance for selection programs aiming at reducing and curtailing the first milk yield and calving interval .
Keywords
enetic evaluation of first milk yield and first calving interval; in a herd of Holstein

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