Study of Relative Effectiveness of Different Sire Evaluation Methods in Sahiwal Cattle

The main aim of sire evaluation is to obtain an accurate, efficient and ranking them according to their merit so as to enable the breeder to choose the best bulls. Today, the need for sire evaluation for their additive genetic ability (breeding values) or transmitting ability to its progeny has been recognized. For assessing the breeding values of bulls for the traits viz. age at first calving (AFC), first calving interval (FCI), first lactation milk yield (FLMY), first lactation period (FLP), weight at first calving (WFC) and first service period (FSP), there are several methods of sire evaluation with a wide range of complexity starting from very simple (Simple daughter’s average index) [1], to highly complicated (REML) method. Different methodologies like contemporary comparison, corrected daughter average index [2] equivalent parent, least squares (LS) technique, dairy search index [3], and simple regressed least squares technique (SRLS) could be used. Henderson [4] opined that analysis of variance and covariance may give biased components of variance from selected population, whereas restricted maximum likelihood (REML) estimate can give bias free estimators. The multi traits criteria of sire evaluation using advanced statistical technique like derivative free restricted maximum likelihood (DFREML) and best linear unbiased prediction (BLUP) would be expected to enhance the accuracy of selection of bull. Materials and Methods