Nutritional restriction in lactating primiparous sows selectively affects female embryo survival and overall litter development.
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.
Department of Agricultural, Food and Nutritional Science, Swine Research and Technology Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada.
M D
MD
Vinsky
S
S
Novak
W T
WT
Dixon
M K
MK
Dyck
G R
GR
Foxcroft
D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D004435:Eating; D047108:Embryonic Development / Q000502:physiology*; D004734:Energy Metabolism; D005260:Female; D005298:Fertility; D024282:Genes, sry; D007774:Lactation; D008297:Male; D011247:Pregnancy; D039401:Prenatal Nutritional Physiological Phenomena / Q000502:physiology*; D012744:Sex Ratio; D034421:Sus scrofa / Q000235:genetics / Q000502:physiology*
D004247:DNA