Equalizing light and heavy litters with extra piglet relative to sow functional teats: impacts on lactational...

This study evaluated the effects of litter equalization with different weights and numbers of piglets relative to the number of functional teats on sow and piglet performance during lactation. Litters (n = 183) were equalized based on weight (light: 0.955-1.289 kg; heavy: ≥ 1.399-1.935 kg) and piglet number by total number of functional teats (Eq-0: same number of piglets and teats; Eq + 1: one extra piglet than the teat number). Sow body condition was evaluated during lactation. Piglets were individually weighed and evaluated for face, body, and joint injuries. Females lost more caliper units in heavy litters (-0.39; P = 0.05), with no interaction with Eq-0 or Eq + 1 (P = 0.11). There was no difference in the total number of piglets weaned (P ≥ 0.08) regardless of litter weight, number of piglets by functional teats, or their interaction. Weaning weight and average daily gain were positively affected (P < 0.01) in heavy (6.1 ± 0.1 kg; 227.9 ± 0.3 g/d) compared to light litters (5.5 ± 0.1 kg; 214.0 ± 0.3 g/d). Mortality was not affected by different groups (P ≥ 0.60). However, the percentage of piglets removed before weaning was higher for Eq + 1 (5.21 ± 0.75%) than Eq-0 litters (2.66 ± 0.49%; P < 0.01). Heavy litters had a higher percentage of piglets with facial, body, and joint injuries compared to light litters, regardless of the number of piglets by functional teats. Equalizing litters with one extra piglet resulted in a higher pre-weaning piglet removal rate. Body parameters of sows were not compromised comparing Eq-0 and Eq + 1.