Effect of the Back Fat Thickness and Body Weight of Gilts at the Time of Service on Their Productive Performance During Gestation and Lactation in a Commercial Herd

The objective was to determine the effects of back fat thickness (BFT) and body weight (BW) of gilts at the time of service on their productive performance during gestation and lactation in a commercial herd. BFT and BW were measured at the time of service, when entering maternity and weaning. Gilts were classified into tertiles according to BFT (low [< 17 mm], moderate [17-15 mm], and high [> 20 mm]) and BW (light [< 140 kg], moderate [140-150 kg], and high [> 150 kg]) at the time of service. A higher (p < 0.05) lactating feed intake (4.5 kg/day) was observed in gilts with BFT < 17 mm. Classification based on BW at the time of service did not show any differences in feed intake during lactation. The greatest (p < 0.05) loss of back fat (4.7 mm) during lactation was observed in gilts with a BFT > 20 mm. The total number of piglets born, piglets born alive, and weaned piglets was higher (p < 0.05) in gilts with a BFT of 17-20 mm. In summary, it was shown that feed intake, weight loss, back fat during lactation, and litter performance were mostly affected by the BFT with respect to BW.