Effects of Bacillus subtilis and l -arginine supplementation during early gestation on reproductive performance in sows

This study evaluated the effects of Bacillus subtilis and l-arginine supplemented during early gestation on reproductive performance in sows. Sows were assigned to four treatments: a control diet or supplementation with B. subtilis, l-arginine, or their combination, from day 5 to 30 of gestation. Reproductive traits were recorded at farrowing and analyzed using linear and generalized linear mixed-effects models. No treatments had significant effects on litter size, piglets born alive, litter birth weight, birth weight variability, farrowing duration, birth interval, or stillbirth and mummification rates ( p > 0.05). Compared with the control group, combined group tended to have a lower individual birth weight of all piglets (1296 vs. 1426 g; p = 0.064) and exhibited a significantly lower individual birth weight of live-born piglets (1356 vs. 1486 g; p = 0.027). In addition, the combined group showed a lower proportion of piglets weighing more than 1.5 kg (30.5 vs. 50.7%; p = 0.021) and a tendency toward a higher proportion of piglets weighing less than 1.1 kg (23.0 vs. 15.5%; p = 0.071). No interaction effects between B. subtilis and l-arginine were detected. In conclusion, under the conditions of this study, supplementation with B. subtilis and l-arginine during early gestation did not confer significant benefits in sows.