Post-insemination level of feeding does not influence embryonic survival and growth in highly prolific gilts.

This study was designed to investigate the influence of a high level of feeding during early gestation on embryonic survival and variability of embryonic development in hyperprolific LW gilts. During the 7 days after the first insemination, gilts were fed either 4 or 2kg daily of a gestation diet (groups High, n=15, and Control, n=13, respectively). Gilts were slaughtered at 27.0+/-0.1 days of pregnancy. Embryonic survival was 85.4+/-1.0% and the number of surviving embryos averaged 17.5+/-0.6. Embryos weighed 0.88+/-0.17g and measured 20.6+/-1.1mm, and within-litter variability in embryo weight averaged 11%. None of these criteria was significantly influenced by the level of feeding during the first week of pregnancy. Irrespective of nutritional treatment, embryonic survival was not related to ovulation rate or length of the uterine horns. Number of living embryos was not correlated with embryo weight and length. Within-litter variation in embryo weight or length was not correlated with the number of embryos or embryonic survival. In conclusion, a high level of feeding during early pregnancy of prolific gilts did not reduce embryo survival and had no beneficial nor detrimental effects on embryo size and variability at 27 days of gestation.