Genetic parameters of production efficiency traits in murrah buffaloes

The production efficiency traits of 536 Murrah over a period of 25 years (1990 to 2014) were utilized to estimate the genetic and non-genetic parameters. The mixed linear model used for analysis included the sire as a random effect and period of calving and season of calving as fixed effects. The production efficiency traits included first lactation milk yield (FLMY), first peak yield (FPY), milk yield per day of lactation length (MLL), milk yield per day of calving interval (MCI) and milk yield per day of age at second calving (MSC). The effect of season of calving was statistically non-significant on all traits and the effect of period of calving was statistically significant on FLMY, MLL, MCI and MSC while non-significant on FPY. The overall least square means for FLMY, FPY, MLL, MCI and MSC were 2041.27±32.78 kg, 10.55±0.25 kg/day, 6.59±0.09 kg/day, 4.40±0.07 kg/day and 1.08±0.01 kg/day, respectively. The heritability for different production efficiency traits were 0.26±0.18, 0.24±0.17, 0.29±0.21, 0.30±0.21and 0.28±0.21 for FLMY, FPY, MLL, MCI and MSC, respectively. The effect of season of calving was statistically non-significant on all the above mentioned traits. The effect of period of calving was statistically significant on FLMY, MLL, MCI and MSC while non-significant on FPY. Moderate estimates of heritability and appreciably good estimates of genetic and phenotypic correlation among production efficiency traits indicated that selection based on progeny testing would be effective.