Genetic and Phenotypic Correlation of Some Body Measurements with Milk Yield in Nili Ravi Buffaloes of Pakistan

Abstract

| Genetic correlations between any two traits indicate that some of the same genes are controlling them and in case of positive genetic correlation, selection for improvement in one trait will result in improvement in the other trait as a correlated response. In case of absence of any milk recording system under field conditions, farmers generally select animals on the basis of phenotype. Information on genetic correlation of body measurements with milk yield can be used for indirect selection for improved milk yield. Objective of this study was to record different body measurements in Nili Ravi buffaloes and estimation of phenotypic and genetic correlations with milk yield. These correlations were estimated in 437 Nili Ravi buffaloes maintained at 5 Livestock Experiment Sta-tions in Punjab and few private breeders. Data included 1180 records of milking buffaloes. Correla-tions were estimated using BLUP techniques. Age of the buffalo at scoring, stage of lactation, parity, herd and season of scoring were included in the model. Data were analysed using the mixed model procedure of the SAS. Fixed effects observed to be significant in the initial analysis were included in the model for estimation of genetic and phenotypic correlation of each trait with milk yield using bivariate analysis in ASREML computer program. Buffaloes in the data were the progeny of 88 sires and 303 dams with 119 base animals. The least squares means for height at withers, diagonal body length and heart girth were found as 132.04±4.56, 154.01±7.60 and 194.46±10.31cm, respectively. Phenotypic correlations of 305 days milk yield with body measurements were low. Positive genetic correlations were observed as 0.16±0.0003 for diagonal body length, 0.08±0.00 for height at withers and 0.14±0.0005 for heart girth. Diagonal body length has shown a low but positive genetic cor-relation with milk yield and this trait might be considered in the selection program for Nili Ravi buffaloes. Genetic correlation of heart girth with milk yield can be considered for indirect selection for milk yield.