Estimating genetic parameter estimates for productive and reproductive traits in high-grade crossbred dairy cattle at Chokie Enterprise Dairy Farm, northwestern Ethiopia

Abstract

This study estimated genetic parameters and breeding values for productive and reproductive traits in high-grade crossbred dairy cattle at Chokie Enterprise Dairy Farm, northwestern Ethiopia, using 214 records collected from 2012 to 2022. Genetic analyses were performed with WOMBAT software. The estimated heritability (h²) values for age at first service (AFS), age at first calving (AFC), calving interval (CI), days open (DO) and number of services per conception (NSPC) were 0.0002, 0.0002, 0.07, 0.02 and 0.004, respectively. For productive traits, the h² estimates for lactation milk yield (LMY), daily milk yield (DMY) and lactation length (LL) were 0.015, 0.0001 and 0.34, respectively. The average estimated breeding values (EBVs), articulated in phenotypic units, were 0.068441 days for age at first service (AFS), 0.333763 days for age at first calving (AFC), 0.23776 days for calving interval (CI), 0.243223 days for days open (DO), 0.000271 for number of services per conception (NSPC), 4.349835 L for lactation milk yield (LMY), 0.000343 L for daily milk yield (DMY) and 4.438418 days for lactation length (LL). These specific unit-based results elucidate the extent of genetic variation across traits. Heritability and repeatability estimates significantly differ from zero for productive traits, suggesting a genetic basis for improvement through selection. Moreover, strong positive genetic correlations among traits indicate that selection for one productive or reproductive trait may concurrently enhance other traits, supporting integrated genetic improvement in high-grade crossbred dairy cattle.