Altrenogest treatment effects on the reproductive performance of sows during transition to batch farrowing

ABSTRACT: The synthetic progestin altrenogest (ALT) has been widely used in sow farms to concentrate artificial inseminations (AIs) during the transition of weekly productive flow for the batch farrowing system of 14 or 21 days. The objective of the present study was to investigate the effect of the duration of ALT treatment on the reproductive performance of weaned sows during transition to batch farrowing. Retrospective data was evaluated regarding the reproductive performance of primiparous and multiparous sows that were either not treated (control, n = 165) or treated with 20 mg ALT during 7 days (ALT7, n = 161) or 14 days (ALT14, n = 199) post-weaning. The interval between weaning or the end of ALT supplementation and first AI did not differ among the groups, as well as the percentage of sows inseminated up to 7 or 10 days after the end of treatment or weaning (P ≥ 0.16). There was a tendency for a lower farrowing rate (P = 0.06) in ALT7 (77.2%) when compared to ALT14 (84.5%) and control (86.3%) groups. The total number of piglets born did not differ among groups (P = 0.35). In conclusion, despite the slight delay in the estrus onset, the proportion of estrous sows was not affected, whereas the adjusted farrowing rate was reduced when ALT was administered for 7 days after weaning in multiparous sows during transition to 21 days batch farrowing system.

摘要：合成孕激素烯丙孕素（altrenogest, ALT）已被广泛应用于母猪养殖场，用于14日龄或21日龄批次化分娩系统的周生产节律过渡阶段集中开展人工授精（artificial insemination, AI）。本研究旨在探究ALT给药时长对过渡至批次化分娩系统的断奶母猪繁殖性能的影响。本研究回顾性分析了初产与经产母猪的繁殖性能数据，受试母猪分为3组：未给药对照组（control, n=165）、断奶后连续7天给药20mg ALT组（ALT7, n=161）、以及断奶后连续14天给药20mg ALT组（ALT14, n=199）。各组母猪断奶或停止ALT给药至首次人工授精的间隔时长，以及给药/断奶后7天、10天内完成授精的母猪占比均无显著差异（P≥0.16）。与ALT14组（84.5%）及对照组（86.3%）相比，ALT7组的分娩率呈现降低趋势（P=0.06），该组分娩率为77.2%。各组总产仔数无显著差异（P=0.35）。综上，尽管断奶后连续7天给药ALT会略微延迟发情启动，但发情母猪占比未受影响；而在过渡至21日龄批次化分娩系统的经产母猪中，该给药方案会降低校正后分娩率。