Field recording and sire evaluation under Indian conditions*

Abstract

The data on 4 185 lactations from field Holstein crossbreds were used for present analysis. The locations (centre). year and month of calving and exotic blood level of ammals significantly affected the lactational milk yield. Under sire evaluation programme 45 purebred and 20 crossbred Holstein bulls were under test. The data on 40 sires (23 purebred and 17 crossbred) having mimmum 4 daughters were used for this purpose. The estimated sire ment was calculated using different sire evaluation methods; simple daughter average
(SDA), herd mate comparison (HMC), contemporary comparison (CC), least square (LS), and best linear
unbiased prediction (BLUP). The product moment correlations and rank correlations between sire evaluations based on different methods ranged from 0.71 01 to 0.9297. Standard error of sireestlmare (used as measure to compare different
methods) for BLUP was least Amongst bulls tested, 10 purebred and 11 crossbred bulls had reliability of proof of more than 60%. The predicted difference in milk yield of 12 bulls exceeded population average by more than 5%.