Pantnagar Journal of Research

Abstract

Data for the present investigation were collected from a history sheet of crossbred cattle at the Instructional Dairy Farm of G. B. Pant University of Agriculture and Technology, Pantnagar. The data pertained to 1000 crossbred cattle with a total of 3583 calving records from 87 sires distributed over 32 years from 1988 to 2019.The average values for productive herd life, longevity, total calf production, total alive calves born, total female calves born, selective value, and CGR were estimated as 6.58±0.06 years, 9.78±0.06 years, 4.68±0.03, 4.44±0.03, 2.16±0.05, 1.45±0.04, and 0.72±0.02, respectively. The impact of the season was observed significant on productive herd life (PHL), longevity, total calf production, and the number of total alive calves born. However, the effect of season was found to be non-significant on the total number of female calves born, selective value, and calf-growth rate (CGR). The period has been found to have a highly significant effect on all the studied traits. The effect of the First Lactation Milk Yield (FLMY) group was found to have a significant impact on all the traits under study. Longevity had the heritability estimate of 0.32, while other traits such as PHL, total calf production, and total alive calves were also shown from lower to moderate heritability estimates. On the other hand, total female calves born, selective value, and CGR had relatively lower heritability estimates. The genetic and phenotypic correlations among productive herd life, longevity, and selective value and their components ranged from lower to very high. A long productive life of cows increases their life time milk yield and the number of calves born, which has an essential effect on production profitability. Therefore, the optimum lifespan of a cow should be the composite of breeding and economic results. Therefore, the future selection of dairy cattle for productive herd life and longevity breeding will require a fully integrated and balanced breeding model