Estimation of Genetic Parameters of Lifetime Performance Traits in Murrah Buffaloes

The data on 171 Murrah buffaloes sired by 49 pertaining to lifetime performance traits were collected from history cum pedigree sheets maintained at Buffalo Research Centre (BRC), Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar over a period of 20 years from 1990 to 2009. Analysis of variance done by restricted maximum likelihood method of Harvey (1990) using mixed linear regression model with regression effect of age at fi rst calving. The overall least squares means for lifetime milk yield (LTMY), productive life (PL), milk yield per day of productive life (MY/PL), herd life (HL) and milk yield per day of herd life (MY/HL) averaged as 8607.93±481.93 kg, 1161.59±54.17 days, 5.59±0.15 kg/day, 3340.22±120.67 days and 2.55±0.10 kg/day, respectively. The effect of period and season of calving and age at fi rst calving (linear and quadratic) was statistically non-signifi cant on all the lifetime performance traits under study except that signifi cant effect of period of calving on MY/PL. The heritability estimates along with standard errors for different lifetime performance traits were obtained as 0.18±0.10, 0.26±0.17, 0.11±0.04, 0.26±0.20 and 0.29±0.13 for LTMY, PL, MY/PL, HL and MY/HL, respectively. The genetic and phenotypic correlations among lifetime performance traits were positive and high except genetic and phenotypic associationship of HL with MY/HL and MY/PL. Therefore, moderate to high genetic correlations among lifetime traits indicated that selection based on any one of these traits could result into improvement through positive correlated response in all other traits.