TY - JOUR T1 - Estimation of Genetic Parameters and Breeding Values for Test-Day and 305-Days Milk Yields in Some Iranian Holstein Herd AU - , Reza Seyedsharifi AU - , Morad-Pasha Eskandari-Nasab AU - , Abdollah Sobhani JO - Journal of Animal and Veterinary Advances VL - 7 IS - 11 SP - 1422 EP - 1425 PY - 2008 DA - 2001/08/19 SN - 1680-5593 DO - javaa.2008.1422.1425 UR - https://makhillpublications.co/view-article.php?doi=javaa.2008.1422.1425 KW - Avian pox KW -virus KW -peacock KW -isolation KW -electron microscope AB - Test day milk yield records of 68956 first-parity Holstein cows were used to estimate genetic parameters for milk yield. Comparison of breeding value of two evaluation method include test day and classical model (305 days) indicated that the EBVs for TD milk yields are closely correlated with EBVs for 305 days milk yields. Genetic correlations between individual test days and 305 days were high. Results suggested that test day milk yields, mainly in mid-lactation, can be used of 305 days milk yield in genetic evaluation. the heritability estimate of milk yield under the TD model is lower than the corresponding estimate for 305-days milk yield. ER -