Koutsotheodoros F, Hughes P E, Parr R A, Dunshea F R, Fry R C, Tilton J E
Department of Animal Production, Institute of Land and Food Resources, The University of Melbourne, Parkville, Victoria, Australia.
Anim Reprod Sci. 1998 Jun 30;52(1):71-9. doi: 10.1016/s0378-4320(98)00088-8.
This study investigated the effects of feeding the orally active progestagen, altrenogest (Regumate) post-weaning on the subsequent reproductive performance of early weaned sows. Ninety (90) Large White/Landrace first parity sows were randomly assigned to three treatments. Treatment 1 (EW) and treatment 3 (CW) sows were weaned on day 12 and day 24 post-partum, respectively while treatment 2 sows (EW-R) were weaned on day 12 post-partum and received an individual daily dose of 20 mg of Regumate on days 13 to 24 post-partum inclusive. Each sow was mated naturally at least twice at the first post-weaning or post-treatment oestrus and slaughtered on days 25-28 of pregnancy to determine the number of corpora lutea and embryos. Regumate-to-oestrus and weaning-to-oestrus intervals were similar for EW-R and CW sows (6.2 vs. 5.6 days). However, both intervals were significantly shorter (P < 0.01) than the weaning-to-oestrus interval of EW sows (7.3 days). An excellent synchronization of oestrus was achieved with Regumate treatment with 97% of treated sows in oestrus within 7 days of Regumate withdrawal compared with 64% for EW sows (P < 0.01) and 87% for CW sows (P > 0.05). Treatment with Regumate resulted in a significant increase in ovulation rate (16.9 vs. 15.4 and 14.9 for treatments EW-R, EW and CW, respectively; P < 0.05) and a non-significant increase in early embryonic survival (77% vs. 68% vs. 68% for treatments EW-R, EW and CW, respectively; P > 0.05). These results indicate that Regumate feeding is a potential management tool to alleviate the diminished reproductive performance associated with early weaning regimes since it leads to successful control of oestrus, higher ovulation and embryo survival rates and thus a greater potential litter size.
本研究调查了断奶后饲喂口服活性孕激素烯丙孕素（Regumate）对早期断奶母猪后续繁殖性能的影响。九十头大白/长白初产母猪被随机分为三个处理组。处理1（EW）和处理3（CW）组的母猪分别在产后第12天和第24天断奶，而处理2组的母猪（EW - R）在产后第12天断奶，并在产后第13天至第24天（含第24天）接受每日20毫克Regumate的个体剂量。每头母猪在断奶后或处理后的首次发情期至少自然交配两次，并在妊娠第25 - 28天屠宰，以确定黄体和胚胎的数量。EW - R组和CW组母猪从饲喂Regumate到发情以及从断奶到发情的间隔相似（分别为6.2天和5.6天）。然而，这两个间隔均显著短于EW组母猪的断奶到发情间隔（7.3天，P < 0.01）。Regumate处理实现了良好的发情同步，97%的处理母猪在停止饲喂Regumate后7天内发情，相比之下，EW组母猪为64%（P < 0.01），CW组母猪为87%（P > 0.05）。Regumate处理导致排卵率显著增加（EW - R、EW和CW组处理分别为16.9、15.4和14.9；P < 0.05），早期胚胎存活率虽有增加但不显著（EW - R、EW和CW组处理分别为77%、68%和68%；P > 0.05）。这些结果表明，饲喂Regumate是一种潜在的管理工具，可缓解与早期断奶制度相关的繁殖性能下降，因为它能成功控制发情，提高排卵率和胚胎存活率，从而增加潜在窝产仔数。
