Multiple linear correlation and prediction of lifetime performance on the basis of first lactation fertility and production traits in Karan Fries (Holstein Friesian crossbred) cattle

Abstract

Higher productions along with superior fertility are the functions of greater stayability of dairy cattle in the herd. Present investigation was undertaken to evaluate lifetime traits and their prediction on the basis of first lactation traits in Karan Fries cows maintained at National Dairy Research Institute. Data of 5878 lactation records of 1988 adult cows pertaining to the period between 1978 to 2012, were collected for analysis. The phenotypic and genetic correlations of first lactation with lifetime traits were estimated and lifetime performance was predicted using backward elimination multiple linear regression models. Cumulative milk yield (CMY) analysis indicated that the Karan Fries cows achieved around 85% of their lifetime production by 4^th lactation. Phenotypic and genetic correlations of lifetime production traits were positive with first lactation production traits, whereas the association was negative with first lactation fertility traits. The coefficient of variation and mallows Cp criterion estimates of better fit models were lower and ranged between 12 to 18% and 2.51 to 6.00, respectively. Results indicated that the first lactation traits used for the prediction, best explained the variation in traits such as Lifetime yield upto two lactations (51.00%) and breeding efficiency (51.43%), on the basis of coefficient of determination (R²)estimates. Regression models for predicting lifetime yield upto three lactations, milk yield per day of productive life and lifetime daughter pregnancy rate had moderate coefficient of determination estimates.