Long-term phenotypic selection of Akkaraman sheep to establish a sustainable dairy population under semi-arid conditions in Türkiye.

This study aimed to assess the possibility of developing a dairy population of Akkaraman sheep following a long-term within-breed phenotypic selection program in semi-arid conditions in Türkiye. The study was conducted at Gözlü State Farm between 2012 and 2023 (12 years), covering approximately 3-4 generations, and included milk yield records from 6,822 purebred Akkaraman ewes. Milk yields were recorded on days 1, 45, 60, 75, 90, 105, and 120 of lactation. Quadratic spline interpolation based on these test-day means was used to reconstruct daily milk yield and to standardize lactation performance over a 120-day period; no formal genetic parameter estimation (e.g., BLUP, REML) was applied. Across the 12-year study period, the mean lactation milk yield reached 119.15 kg, with a mean daily milk yield of 0.99 kg, representing approximately a 2.5-fold increase compared with historical reports for the Akkaraman breed. The lactation curve exhibited a gradual peak followed by a sustained production phase, indicating a shift toward a more dairy-type lactation pattern. The results indicate that continuous within-breed phenotypic selection significantly enhances milk production in a fat-tailed, dual-purpose sheep breed without crossbreeding while preserving adaptation to semi-arid production conditions. The findings show that local sheep breeds can help create environmentally friendly and sustainable dairy production in areas with limited resources.