Vinsky M D, Novak S, Dixon W T, Dyck M K, Foxcroft G R
Department of Agricultural, Food and Nutritional Science, Swine Research and Technology Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada.
Reprod Fertil Dev. 2006;18(3):347-55. doi: 10.1071/rd05142.
This study explored the possibility of sex-specific effects on embryonic survival in primiparous sows subjected to restricted feed intake during the last week of lactation and bred after weaning (Restrict; n = 16), compared with control sows fed close to ad libitum feed intakes (Control; n = 17). Restrict sows were in a substantial negative net energy balance at weaning, and lost 13% of estimated protein and 17% of fat mass during lactation, yet the weaning-to-oestrous interval and ovulation rate were not different between treatments. However, embryonic survival at Day 30 of gestation was lower (P < 0.05) in Restrict than Control sows, and selectively reduced the proportion of female embryos surviving (P < 0.01). A decrease in weight and crown-rump length of surviving female (P < 0.05) and male (P < 0.05) embryos was seen in Restrict litters. The mechanisms mediating this sex-specific effect on embryonic loss in feed-restricted sows are unclear. The data presented here indicate that feed-restriction during the last week of lactation in primiparous sows causes a selective decrease in survival of female embryos and limits the growth of all surviving embryos.
本研究探讨了初产母猪在泌乳期最后一周采食量受限并在断奶后配种（限饲组；n = 16）时，对胚胎存活产生性别特异性影响的可能性，并与自由采食的对照母猪（对照组；n = 17）进行比较。限饲组母猪断奶时处于显著的负净能量平衡状态，泌乳期间估计损失了13%的蛋白质和17%的脂肪量，但不同处理间断奶至发情间隔和排卵率并无差异。然而，限饲组母猪妊娠第30天时的胚胎存活率低于对照组（P < 0.05），且选择性地降低了存活雌性胚胎的比例（P < 0.01）。在限饲组仔猪中，存活的雌性（P < 0.05）和雄性（P < 0.05）胚胎的体重和顶臀长均有所下降。泌乳期最后一周对初产母猪进行限饲导致雌性胚胎存活率选择性降低并限制所有存活胚胎生长的机制尚不清楚。此处呈现的数据表明，初产母猪泌乳期最后一周的限饲会导致雌性胚胎存活率选择性下降，并限制所有存活胚胎的生长。
