Effects of Ad Libitum Feeding and Arginine Supplementation on Growth of Piglets and Reproductive Performance Parameters of Sows

The study evaluated the effects of ad libitum feeding with or without L-arginine (Arg) supplementation during lactation on sow performance, piglet growth, and sow backfat thickness. Seventy-one sows were assigned to three dietary treatments: restricted feeding without Arg supplementation (CON; n = 24), ad libitum feeding without Arg (AL; n = 26), and ad libitum feeding supplemented with 1% Arg (AL+Arg; n = 21). Dietary treatments began three days postpartum. Average daily energy intake was higher in both ad libitum groups (AL and AL+Arg) compared with the control (91.9 and 91.1, respectively vs. 63.2 MJ/sow/day). Ad libitum feeding, regardless of Arg supplementation, increased sow body weight and backfat thickness at weaning (p < 0.05). Piglets from both ad libitum-fed groups (AL and AL+Arg) had greater weaning weights than piglets from the control group (8.03 and 8.32, respectively vs. 7.41 kg; p < 0.05). Arg supplementation tended to increase total litter weaning weight compared with ad libitum feeding alone. Within the light birth weight class (≤1.00 kg), piglets from the AL+Arg group showed higher daily weight gain than those light piglets from the other treatments. In conclusion, ad libitum feeding during lactation improved sow body condition and piglet growth, while Arg supplementation may be particularly beneficial for improving growth performance of low birth weight piglets.