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.
Vinsky
M D
MD
Department of Agricultural, Food and Nutritional Science, Swine Research and Technology Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada.
Novak
S
S
Dixon
W T
WT
Dyck
M K
MK
Foxcroft
G R
GR
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