Comparative Study of Different Sire Evaluation Methods Using First Lactation Traits in Crossbred Cattle

The records of 1085 crossbred cattle daughters of 57 sires maintained during 1974-2004 at Instructional Dairy Farm of Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India were used to evaluate sires for first lactation performance traits. The data were analyzed to estimate the breeding values of sires using least squares methods (LSM), best linear unbiased prediction (BLUP) and derivative free restricted maximum likelihood (DFREML) method. The average breeding values of sires estimated by all 3 methods were similar and estimated for age at first calving (AFC), first lactation period (FLP), first dry period (FDP) and first calving interval (FCI) as 1359.95 days, 356.56 days, 177.58 days and 534.15 days respectively. The estimated breeding values (EBV’S) showed large genetic variation between sires for first lactation. The EBV’S of sires had very high and significant product moment correlations and rank correlations among all first lactation traits. These results revealed that estimated breeding values of sires estimated for first lactation traits by LSM method showed small genetic variation in comparison to BLUP and DFREML methods. The LSM method was found to be more efficient, accurate, and stable with lowest genetic variation.