In-depth Pedigree Analysis and Inbreeding Effect on Reproduction Traits in Sahiwal Nucleus Herd

Background: Loss of genetic diversity is allied with adverse incidents such as inbreeding depression in fitness related traits, addiction of favorable alleles and enhances fluctuation on selection response. Therefore, the study aims to monitor population structure and avoid unfavorable effects of inbreeding for sustainable improvement in breeding programme. Methods: Pedigree information on 3449 animals born from 1955-2018 was analyzed. The effect on inbreeding on Age at first calving (AFC), Service period (SP), Daughter pregnancy rate (DPR), Calving interval (CI) and pregnancy rate was seen by regression analysis. Result: The pedigree completeness index (PCI) were found to be (%) 92.32, 80.26, 65.22, 49.43% and 32.54 respectively from first to fifth generations. The estimated average inbreeding rate was 2.30% and average genetic diversity loss was 2.64%. Study also revealed significant effect of inbreeding on (AFC, CI and SP) with slightly increasing trends. Hence, it is suggested that more precise pedigree recording and planned mating strategies should be adopted to avoid negative effect of inbreeding in future generation.