Genetic studies on production efficiency traits in Murrah buffaloes.

The present investigation was undertaken on data of Murrah buffaloes from Buffalo Research Centre of the university. Records of 326 Murrah buffaloes distributed over 20 (1987 to 2006) years were analyzed. The overall means were 1937.88 kg, 10.16 kg, 194.12, 6.09 kg/day, 3.98 kg/day and 1.00 kg/day for first lactation milk (FLY), first lactation peak yield (FPY), persistency (P), average milk yield per day of first lactation (AYL), milk yield per day of first calving interval (MCI) and milk yield per day of age at second calving (MSC), respectively. The effect of period of calving was significant on P, AYL and MSC but, the effect of season of calving was nonsignificant on all the traits under study. The summer calvers were excellent for the traits under present study. The effect of age at first calving (linear) was significant on FLY, AYL, MCI and MSC. The effect of AFC (quadratic) on all the production and its efficiency traits were nonsignificant. The estimates on heritability were low to moderate (0.19 to 0.32). The genetic and phenotypic correlations were high barring some exceptions. High genetic and phenotypic correlations of FPY with production efficiency traits except with persistency indicate that FPY can be used as a selection criterion. MSC can be used as an index trait in selection programme as it is associated with AFC and milk yield.