Comparison of changes in fatness of sows in high pregnancy and at weaning and determination of their association with reproduction results and rearing of piglets

Abstract

Sixty crossbred sows were investigated for the effect of the level of fat reserves in high pregnancy and pre-weaning changes in lipid reserves on reproductive performance of sows and rearing of piglets. At 104 days of pregnancy and at weaning, sows were analysed for body weight, P2 and P4 backfat thickness and M. Longissimus dorsi (MLD) thickness at P4M (Piglog 105). Sows were grouped according to mean backfat thickness (P2 + P4)/2 at 104 days of pregnancy into primiparous (P2 + P4)/2>18 mm (group I), primiparous (P2 + P4)/2≤18 mm (group II), multiparous (P2 + P4)/2>20 mm (group I) and multiparous (P2 + P4)/2≤20 mm (group II). The body weight of sows from group I was higher than sows from group II at 104 days of pregnancy (P ≤ 0.05) and at weaning (P ≤ 0.01). As assumed in the experiment, fatness in high pregnant sows (points P2 and P4) was significantly higher in group I than in group II (P ≤ 0.01), and the differences between the groups persisted when piglets were weaned (P ≤ 0.01). At weaning, sows from group II had a significantly greater P4M thickness compared to sows from group I. The differences in backfat thickness in late-pregnant sows in groups I and II and in the loss of fat reserves during a 21-day lactation had no effect on reproduction results and rearing of piglets. Sows lost body weight to a small extent and fat reserves to a moderate degree; the changes were greater in primiparous than multiparous sows, regardless of the group (I or II).