Estimation of genetic and phenotypic trends of first lactation reproduction traits in Phule Triveni cattle of Maharashtra

Abstract

The main objective of the present investigation was to study the genetic, phenotypic and environmental trends for first lactation reproduction traits in Phule Triveni population reared at Research Cum Development Project (RCDP), Mahatma Phule Krishi Vidyapeeth, Rahuri (Maharashtra), India. Reproduction traits were age at first calving (AFC), first service period (FSP) and first calving interval (FCI). The edited data set includes 493 first lactation performance records (1977 to 2012) of Phule Triveni cows. The data were analysed by the least squares technique to determine the influence of environmental factors. (Co) variance components of all traits were estimated by the average information maximum likelihood method (AIREML) algorithm in WOMBAT software. Best linear unbiased prediction (BLUP) of breeding values was carried out by univariate sire model. The least squares mean for AFC, FSP and FCI were 985 ± 2, 151 ± 5 and 430 ± 4 days, respectively. The annual genetic trends were obtained by Smith 2 (SM-2) and BLUP methods for the traits studied. The genetic trends for reproductive traits under study were found negative or low, positive and non-significant indicating an evident positive effect of selection and improved management in the herd. Estimates of phenotypic and environmental trends were positive for all the reproductive traits and high positive magnitudes of the environmental trends resulted in worsening the phenotypic trends of reproductive traits under study in Phule Triveni cows.