Effects of Crossbreeding on Growth Performance and Carcass Traits in Sheep Under Extensive Pasture Systems

Improving meat productivity of sheep under extensive pasture systems is essential for food security in arid regions. This study evaluated the effects of crossbreeding on growth performance and carcass traits of ram lambs raised exclusively on natural pastures without supplementary feeding in the Pavlodar and Abai regions of Kazakhstan. Four genotypic groups were studied: purebred Kazakh Coarse-wooled (CW × CW, n = 30), Meat Merino × Kazakh Coarse-wooled (MM × CW, n = 30), purebred Kazakh Semi-coarse-wooled (SCW × SCW, n = 30), and Kazakh Meat-Wool × Kazakh Semi-coarse-wooled (MW × SCW, n = 30). Live weights and growth performances were recorded from birth to 4-4.5 months of age. A sample slaughter of five ram lambs per group was conducted to evaluate carcass characteristics and meatiness coefficients. Data were analyzed using one-way ANOVA followed by Tukey's HSD test. Crossbred lambs demonstrated significantly higher growth performance compared with purebred counterparts. Pre-slaughter live weight and carcass weight were highest in crossbred groups, while dressing percentage reached 54.0% (p < 0.001). The highest meatiness coefficient was observed in MW × SCW lambs (5.15), indicating superior carcass composition. Crossbred lambs showed a 20% increase in carcass weight and a 21-44% higher meatiness coefficient compared with purebred groups. The MW × SCW genotype exhibited the best overall performance. These findings indicate that crossbreeding is a practical genetic strategy for improving growth performance, carcass traits, and meat productivity under low-input pasture-based systems and may be applicable to sheep production in similar arid and semi-arid regions.