This paper reviews experiences with evaluating the sires using different sire evaluation methods. The different studies were compiled from oldest to latest published literature on different sire evaluation methods used by different workers and compared effectiveness of various methods of sire evaluation. During the past, different methods like simple daughters average index (i), contemporary comparison method (CC), least squares method (LSM), simplified regressed least squares method (SRLS) and best linear unbiased prediction (BLUP) and derivative free restricted maximum likelihood (DFREML) method and WOMBAT. The different sire evaluation methods like simple daughters average index (i), contemporary comparison method (CC), least squares method (LSM), simplified regressed least squares method (SRLS) and best linear unbiased prediction (BLUP) have been used to evaluate sires but still the application of latest and complex method of sire evaluation like derivative free restricted maximum likelihood (DFREML) and WOMBAT is scanty. However, with the advancement of computational facilities, complex methodologies like DFREML have been used during last few years for sire evaluation in different countries. The effectiveness of different sire evaluation methods was judged by using the various criteria like within sire variance or error variance, coefficient of determination (%), coefficient of variation (%) and rank correlations. The most efficient method had the lowest error variance. Higher the coefficients of determination (R2-value) from fitting a model, higher the accuracy. The sire evaluation method, which retains the coefficient of variation (CV %) of the population near to the CV (%) unadjusted data was the most stable method. Higher (near to unity) rank correlation amongst the sires from different sire evaluation methods revealed higher degree of similarity of ranking from different methods.
The breeding values of sires using derivative free restricted maximum likelihood method (DFREML), best linear unbiased prediction (BLUP), least squares methods (LSM) and WOMBAT were estimated in different studies. In some studies on the basis of some traits the highest breeding value of sires was obtained by LSM and lowest by BLUP than average breeding value. The estimated breeding values estimated by BLUP showed small genetic variation in compare to WOMBAT, LSM and REML method. The error variance estimated by BLUP was found lowest than the other methods. 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 some studies. While in other studies the error variance of DFREML method was lowest and therefore, it was considered to be most efficient method than the other sire evaluation methods.