Estimation of Sire,s Breeding Value by Animal Model and Conventional Methods for Milk Production in Crossbred Cattle

The records of 1198 crossbred cattle daughters of 102 sires maintained during 1966-2010 at Instructional Dairy Farm of G. B. Pant University of Agriculture & Technology, Pantnagar were used to evaluate sires for first lactation performance traits. The data were analyzed to estimate the breeding values of sires using Derivative Free Restricted Maximum Likelihood Method (DFREML), Best Linear Unbiased Prediction (Blup), Least Squares Methods (LSM) and WOMBAT. The highest breeding value of sires for first lactation milk yield was obtained by LSM (2779.19kg) and lowest by BLUP(2629.80kg) than average breeding value respectively. The estimated breeding values estimated by BLUP showed small genetic variation in compare toWOMBAT, LSM and REML method.The error variance estimated by BLUP was found lowest than the other methods. Product moment correlation among breeding values of sires estimated by different methods ranged from 0.566 (LSM with BLUP) to 0.997 (WOMBAT with BLUP ), where as rank correlations of breeding value of sires ranged from 0.566 (LSM with BLUP ) to 0.745 (WOMBAT withLSM).The higher rank correlations(0.566 to 0.745 )between different sire evaluation methods revealed that there was higher degree of similarity of ranking sires by different methods ranging from about60 to 75 percent. The BLUP method was found to be more efficient, accurate and stable with lowest genetic variation amongst all four methods of sire evaluation used in the present study.