Arginine improves nutritional quality of sow milk and piglet performance

ABSTRACT The objective of this study was to evaluate the effect of L-arginine supplementation in lactation diets on the productive and reproductive performance of pluriparous sows and their litters. Seventy-six sows of the same genetic line were assigned to four treatments in a completely randomized design with 19 replicates. The experimental unit was the sow and its respective litter. Treatments comprised a control diet (no L-arginine supplementation) and other three diets obtained by top dressing the control diet with 0.5, 1.0, and 1.5% of L-arginine. L-arginine supplementation had no effect on any performance variables, body condition, milk production, or weaning-estrus interval. There was a quadratic effect on percentage of protein and fat in milk as well as on the daily production of these components. Protein and fat percentage declined during lactation. Adding L-arginine to the diet had a quadratic effect on piglet weight at 13 and 21 days, the optimal level of L-arginine supplementation being estimated as 0.64% and 0.71%, respectively. L-arginine supplementation had a quadratic effect on the weight gain of piglets during the first 13 days and on total period of lactation, the optimal level of L-arginine supplementation being estimated as 0.60% and 0.70%, respectively. Supplementing lactation diets with 0.70% of L-arginine, corresponding to 45 g day−1, improves the weight gain of piglets by improving the nutritional quality of sow milk.