Investigation of the Relationship Between Ovine Selection Signature DIS3 Like 3′‐5′ Exoribonuclease 2 ( DIS3L2 ) Gene and Weaning Weight and Average Daily Gain Until Weaning in Lambs

ABSTRACT The growing demand for animal products, combined with declining livestock production due to urbanization and climate change, underscores the need for sustainable breeding strategies. In sheep production, liveweight and weight gain until weaning are key economic traits. Selection signature analyses have previously identified the DIS3L2 gene, located on OAR2 (~233 Mbp), as a candidate under positive selection for body weight and morphology in sheep. However, its direct association with growth traits remained uninvestigated. This study explored the association between a splice region variant in the DIS3L2 gene (rs421664828) and pre‐weaning growth traits in four indigenous sheep breeds in Türkiye: Central Anatolian Merino, Karayaka, Akkaraman, and Morkaraman. A total of 1862 lambs from 10 herds were genotyped using a custom TaqMan Genotyping assay. Body weights were recorded at birth and on Days 30, 60, and 90, with average daily gain (ADG) calculated until weaning. The AG genotype was the most prevalent (92.1%), and all breeds deviated from Hardy–Weinberg equilibrium. Association analysis revealed significant effects of rs421664828 on weight at Days 60 and 90 and on ADG‐90. The AG genotype was consistently associated with higher growth performance. These findings support the use of DIS3L2 ‐rs421664828 in marker‐assisted selection to enhance growth traits in sheep.