Calidad del semen porcino conservado a 5 °C y su efecto en la fertilidad y tamaño de camada de cerdas en el trópico

In the Mexican tropics, high temperatures affect semen quality and complicate the transport of refrigerated doses. This study evaluated boar semen stored at 5 °C and its effects on semen quality and reproductive performance compared with conventional storage at 17 °C. Initially, 60 ejaculates from four Pietrain/Duroc/Yorkshire boars were processed. After 24 h of stabilization at 17 °C, semen was centrifuged at 2400 rpm (800 × g) for 5 min, resuspended in LEY cooling extender containing lactose (248 mM), kanamycin (0.8 g/L), and egg yolk (20% v/v), and cooled to 5 °C over 120 min (0.11 °C/min). Semen quality was assessed upon reaching 5 °C and after 24 h of storage. For field evaluation, 84 multiparous Yorkshire/Landrace sows were inseminated post-cervically with semen stored at 5 °C (n = 42) or 17 °C (n = 42). Fertility was assessed through non-return to estrus at 21 days, transabdominal ultrasound at 42 days, and farrowing rate and litter size at farrowing. Motility, acrosomal integrity, and osmotic tolerance remained unchanged after 24 h at 5 °C (p ≥ 0.05), while viability increased significantly (91.30 ± 0.18% vs. 89.46 ± 0.18%; p ≤ 0.05). Gestation/farrowing rates were similar between treatments (85.71% vs. 80.95%; p ≥ 0.05), as were total born and live-born piglets. However, stillborn piglets were significantly fewer in the 5 °C group (0.19 ± 0.67 vs. 0.51 ± 0.98; p ≤ 0.05). These findings indicate that boar semen can be stored at 5 °C under tropical conditions while maintaining reproductive performance comparable to conventional storage. This approach offers a practical alternative for improving artificial insemination logistics and potentially reducing antibiotic use.