Abstract
This study evaluated growth and reproductive traits in two sheep breeds in Türkiye, Akkaraman (AKK) and Central Anatolian Merino (CAM), with a focus on the impact of non-genetic factors. Data were analysed from 21,414 AKK and 20,099 CAM lambs for birth weight (BW) and 27,528 AKK and 24,639 CAM lambs for weaning weight (WW), average daily weight gain (ADWG) and Kleiber ratio (KR) using a linear mixed model. AKK lambs showed a significantly higher mean BW (4.19 ± 0.01 kg) than CAM lambs (4.02 ± 0.01 kg) (p < 0.001), whereas CAM lambs had significantly higher WW, ADWG and KR (p < 0.001 for each trait). Fixed effects of sex, birth type, dam age, birth year, herd size and season significantly influenced all growth traits (p < 0.05). Male lambs demonstrated higher BW, WW, ADWG and KR than females (p < 0.001), and single-born lambs had significantly higher BW and WW than twins (p < 0.001). Dam age also influenced all growth traits, with lambs from younger dams tending to be heavier (p < 0.001). In terms of survival, AKK lambs exhibited a significantly higher survival rate (93.85%) than CAM lambs (89.50%) (p < 0.001). Conception rates were similar for both breeds (92.9% for AKK and 92.3% for CAM), whereas CAM lambs showed higher fecundity and litter size. These findings underscore the breed differences in growth and reproductive traits and highlight the importance of considering non-genetic factors to inform breed-specific management practices aimed at optimizing productivity.