CORRELATION OF LINEAR TYPE TRAITS WITH MILK YIELD IN NILI RAVI BUFFALOES OF PAKISTAN

Abstract

Nili Ravi buffaloes are considered black gold being highest milk producers in the world. The study was performed for genetic evaluation of linear type traits and explore their relationships with milk production traits of Nili Ravi buffaloes. Data on Nili Ravi Buffaloes (n=437) present at 5 experimental livestocks farms in Punjab, Pakistan were recorded for linear type traits follwoing ICAR gudelines and adopting a linear scale of 1-9 during 2010-2012 encompassing 1180 records for each trait. A mixed effect model was applied where herd, year, parity, season were fitted as fixed effects and age as covariable. All analyses were performed by using Proc GLM of the SAS software. Variance components were estimated by ASREML software and genetic parameters were computed by post-processing. Least square means for linear scores of stature, chest width, body depth, angularity, rump angle and rump width were 5.07±1.35, 5.23±2.35, 5.41±1.49, 5.76±0.98, 6.73±1.53, 4.91±1.85, respectively. Corresponding genetic correlations (rG) of linear scores of the traits with test day milk yield were 0.57±0.05, 0.09±0.02, 0.31±0.04, 0.06±0.02, 0.15±0.03 and 0.30±0.05, respectively while with 305 days milk yield were 0.14±0.00, 0.04±0.00, 0.21±0.00, 0.02±0.00, 0.11±0.00 and 0.19±0.00, respectively. It was found that some of traits (stature, body depth and rump width) had considerable amount of rG with milk yield. It is therefore suggested that any selection model for Nili Ravi buffalo must contain these useful linear type traits.