Endocrine Abstracts

Increasing energy intakes of sows may decrease the severity of changes in body condition occurring throughout the reproductive cycle and lead to improved efficiency of energy utilisation. The study aimed to examine the effects of feeding extra energy during late pregnancy on body fat deposition, reproductive performance and plasma insulin concentration.

Twenty-four multiparous sows were randomly allocated to one of three dietary treatments. From day 85 of gestation until term (115d) sows were offered either (i) the standard diet (C: 3kg of Pigbreed Pioneer Pellets, BOCM: 12.4 MJ/kg, 3% fat: n=8) or the standard diet plus 30% extra energy derived from either (ii) excess standard diet (E: n=8) or (iii) palm oil (PO: n=8). Sow backfat thickness was measured ultrasonically at service and at 109 days of pregnancy when a blood sample was also obtained. Sows were allowed to farrow naturally at term and number of piglets born alive, dead and mummified were recorded. Plasma samples were analysed for insulin using a porcine EIA. Differences between treatments were assessed using a General Linear Model, ANOVA; values are presented as mean±SEM.

Litter sizes were similar between treatments. In contrast, the percentage of mummified piglets (C: 0.5±3.2, E: 14.4±0.3, PO: 4.1±0.3%), gain in backfat thickness during pregnancy (C: 3.6±1.5, E: 7.2±1.0, PO: 4.5±1.1 mm), and plasma insulin concentration (C: 0.113±0.03, E: 0.224±0.03, PO: 0.151±0.03 micrograms per litre) were greater (P<0.05) in the E sows than the C or PO groups.

In conclusion, maternal dietary supplementation during late pregnancy has a pronounced impact on piglet outcome. A high rate of fat deposition during pregnancy in conjunction with elevated plasma insulin concentration had a detrimental affect on foetal survival.

This work was funded by DEFRA.