The influence of plane of nutrition in early pregnancy on the survival and development of embryos in the sow.

Abstract

Three groups of fifteen sows were given from the day following service 3, 6 or 9 lb meal a day until slaughter on the 28th day after mating. Mean weight gains were 6, 40 and 65 lb respectively. Five sows failed to conceive but there was no influence of treatment on conception rate. There was a significant relationship between number of corpora lutea and weight of sow at service (P<0\m=.\01)and between number of corpora lutea and number of normal embryos (P<0\m=.\001). When adjustment was made for differences in sow weight at service there were no significant effects of treatment on number of normal embryos or survival rate. Mean number of corpora lutea increased with plane of feeding but this difference between treatments was not significant. There were no treatment effects on either weight or crown\p=m- rump length of embryos, but the mean weight of embryonic membranes and mean volume of embryonic fluids were significantly greater on the low plane of feeding than on the medium and high planes (P <0\m=.\05).