Genetic analysis of fertility traits in Jersey crossbred cows

Abstract

The present study was carried out to evaluate the genetic and non-genetic factors affecting fertility traits viz., number of service per conception (NSPC), service period (SP) and calving interval (CI) and genetic and phenotypic parameters of these traits in Jersey crossbred cattle, maintained at Eastern Regional Station of ICAR-National Dairy Research Institute, Kalyani, West Bengal over a period of 39 years (1976-2014). The least squares means for the NSPC, SP and CI were 1.73±0.08 inseminations, 156.37±7.47 days and 458.32±9.56 days respectively. The study revealed that all the traits were decreasing significantly with parity number. Season was important in determining service period, whereas period of calving influenced calving interval in this study. NSPC, SP and CI did not differ significantly among different genetic groups; but, half-breds of Jersey and Tharparkar (½ Jersey-½ Tharparkar) showed comparatively lower NSPC, SP and CI than half-breds of Jersey and Red Sindhi and other crosses in this study. The random effect of sire was highly significant on all the fertility traits considered in this study. Heritability estimates for NSPC, SP and CI were 0.08±0.06, 0.18±0.08 and 0.16±0.08 respectively. All the three analyzed traits had close genetic relationships. Low to moderate heritability of reproductive traits indicates slow genetic progress through selection and further improvement in reproductive performance can be made either by better management practices or including large number of polymorphic markers associated with fertility in the population to assist animal selection