Single-marker and Haplotype-based Analyses of POU1F1 and GH1 Reveal Stage-dependent Effects on Growth Traits in Goats

Abstract

This study investigated the association between growth traits in goats and polymorphisms in the POU1F1 (AluI and PstI) and GH1 (HaeIII) genes using both single-marker and haplotype-based approaches. A total of 79 goats were genotyped, and growth performance was evaluated based on body weight (BW), average daily gain (ADG), and relative growth rate (RGR) across developmental stages. All loci were polymorphic; however, the POU1F1/PstI locus deviated from Hardy-Weinberg equilibrium (P=0.003). Association analyses revealed that the POU1F1/PstI locus was significantly associated with ADG and RGR in a stage-dependent manner, including ADG3-6 (P=0.024), ADG3-10 (P=0.023), and RGR0-3 (P=0.003). In contrast, the POU1F1/AluI locus showed limited and stage-dependent effects, with significant associations confined to later stages, particularly for body weight at 6 and 10 months and cumulative post-weaning gain (P<0.05), while no effects were detected during early growth. The GH1/HaeIII locus showed no significant associations with any growth traits (P>0.05). Additive and dominance models further supported the contribution of the POU1F1/PstI locus to growth rate variation. In addition, four haplotypes were identified with T-T being the most frequent (71.2%) and tending to show more favorable post-weaning growth performance. Overall, POU1F1, particularly the PstI polymorphism and linked haplotypes, showed stronger associations with goat growth traits than GH1. Because the population was small and some genotype classes were unbalanced, these results remain preliminary and require validation in larger, diverse populations before practical use in selection programs.