This study aimed at determining the effects of dietary arginine supplementation during gestation and lactation on the lactation performance of first-partiy sows. On a weekly basis, BW and backfat (BF) thickness of sows, as well as piglet BW were measured, and blood and milk samples were obtained from the sows. Number of days from weaning to estrus and ADFI were also recorded. It was found that there were no differences in BW, BF thickness, ADFI, or days until return to estrus among treatment groups. Also, there was no effect of the gestation diet or a gestation × lactation diet interaction on any parameter measured. Weight gain of piglets from sows fed the Arg-supplemented diet during lactation was greater between d 0 and 7 and between d 0 and 21 of lactation compared with piglets
from sows fed the control diet. Collectively, results from this study indicate the potential beneficial effects of
dietary Arg supplementation in improving the lactation performance of first-parity sows.