Ejaculate traits of ram lambs with different rectal temperatures under heat stress conditions. Impacts of heat stress on semen traits in rams with different rectal temperature

• Published in: Revista Colombiana de Ciencias pecuarias 2025, Vol.38 (2)
• Main Authors: McCormick Palacios, Jorge Humberto, Ramírez-Valverde, Gustavo, García-Muñoz, Canuto, Maldonado-Jáquez, Jorge-Alonso, Hernández-Aquino, Saúl, Flores-Garivay, Rodrigo, Camacho-Morales, Reyna-Lucero, Avelar-Lozano, Ernesto, González-Maldonado, Juan
• Format: Article
• Language: English
• ISSN: 0120-0690; 2256-2958
• DOI: 10.17533/udea.rccp.v38n2a7

Background: heat stress diminishes semen quality in rams. Objective: to evaluate productive and reproductive responses of rams and ram lambs with different rectal temperatures under heat stress conditions. Methods: the animals (n=12, Dorper × Katadhin × Pelibuey crossbreed, 235 to 730 days old ) were assigned to one of three experimental groups: ram lambs with low rectal temperature (RLLRT), ram lambs with high rectal temperature (RLHRT) and Rams. Results: afternoon rectal temperatures were higher (p≤0.05) in the RLHRT group, and there was no difference (p>0.05) between the Rams and RLHRT groups. The ejaculated volume and sperm concentration were higher (p≤0.05) in the group of Rams than in RLLRT and RLHRT. Mass motility and sperm concentration were lower (p≤0.05) in the RLLRT group than in the RLHRT and Rams groups. Average daily weight gain was not different (p>0.05) between the RLLRT and RLHRT groups. Conclusion: the selection of ram lambs with low rectal temperature under heat stress conditions showed no benefit in terms of average daily weight gain and ejaculate traits.