PSIII-9 The Effect of Sire Line on Reproductive Performance During Lactation

Abstract

Abstract The objective of this study was to estimate the effect of sire line on sow and piglet performance during lactation. Commercial Landrace x Large White females (n = 60) were bred to one of the following sire lines: a purebred Duroc line (Line S1), a synthetic (Line S2), or purebred Duroc (Line S3) from a different genetic source. Matings were balanced by line and parity. Females were fed a common gestation and lactation diet during these respective phases. Sow and piglet data were analyzed as a completely randomized design using the GLM procedure of SAS. Results show that, during lactation, females bred to line S3 lost significantly (P = 0.01) more BW (-16.93 ± 3.56 kg) than females bred to line S2 (-2.00 ± 3.50 kg). However, no evidence of a difference (P = 0.18) in BW loss was detected between females bred to line S3 (-16.93 ± 3.56 kg) vs. Line S1 (-7.90 ± 3.56 kg). Further, sows bred to line S3 weaned significantly (P = 0.03) more piglets (12.0 ± 0.28) than females bred to line S2 (10.9 ± 0.27), but not (P = 0.1) compared to females bred to line S1 (11.7 ± 0.27). No significant effect of line (P > 0.05) or parity (P > 0.05) on total number of piglet’s born, number born alive, number of stillborn piglets, or preweaning mortality was detected. The number of mummified fetus tended to be lower in line S2 (0.17 vs 0.66; P = 0.079) and line S3 (0.12 vs 0.66; P = 0.051) sows compared with line S1 sows, respectively. In conclusion, sire line did not have a significant effect on total number born, number born alive, number stillborn, or preweaning mortality. However, females bred to line S3 lost significantly more BW during lact but weaned significantly more piglets than females bred to line S2.