Estimation OF GENETIC GAIN FOR PRODUCTION AND REPRODUCTION TRAITS IN HOLSTEIN FRIESIAN CROSSBRED: ASSESSMENT AND SIMULATION

Abstract

Background: The present analysis aimed to investigate the expected genetic gain along with simulation study for productive and reproductive parameters in Karan fries cattle (Holstein Friesian Х Tharparkar) in particular calving to first insemination interval (CFI), 305 day milk yield (305DMY) and Wet average (WA).

Methods: Data on productivity and reproduction features of Karan Fries cattle kept in an organized herd at the ICAR-NDRI, Karnal were exercised throughout 24-year period from 1993 to 2016. Expected genetic gain (ΔG) of 305 DMY, WA and CFI were calculated by utilizing two separate approaches i.e. Approach I (ΔG = h2) and Approach II (ΔG = iσph2) Additionally ΔG was also determined by simulating various parameters viz. selection intensities (i) and generation interval (GI) for traits related to first lactation productive and reproductive parameters. Also comparative efficacy of the approaches were calculated.

Results: Relative efficiency of approach II over I was observed as 40.65 % more efficient.. In Approach I it was found that when GI was reduced from 5.04 to 4 years, ΔG increased by roughly 26%, 26%, and 25.7 % for FL305DMY, WA, and CFI, but when GI was increased from 5.04 to 6 years, ΔG fell by 15.94%, 16%, and 15.9%.  Approach II revealed that After lowering GI from 5.04 to 4 years and raising i (p = 75 to 70), the ΔG for 305DMY and CFI increased between 44 to 46% and WA increased between 26 to 46%, whereas GI increased from 5.04 to 6 years. The Karan Fries cattle's ΔG ranged from -2 to -16%. The current analysis suggests that in an organized herd To obtain more over 50% yearly ΔG for WA, 305DMY and CFI, the fraction of Karan of animals selected should be 70-75% and GI should be less than 5 years.