PSI-3 - Effects of Increasing Dietary Arginine Supply on Pig Growth Performance Following Weaning Stress

Abstract: Intestinal health has important implications for pig overall health status and growth performance. In this regard, arginine participates in important regulatory functions associated with nutrient metabolism, cell proliferation, and immune response that contribute to the maintenance of a functional intestinal tract. However, today's nutritional practices for weaned pigs do not consider the critical regulatory roles of arginine related to pig gut health and function. The objective of this study was to determine growth response of weaned pigs fed increasing levels of L-Arginine during the first weeks after weaning. A total of 225 weaned pigs (BW 5.8 ± 0.9 kg) were used in a randomized complete block design and assigned to one of five dietary treatments, with 9 replicate pens of 5 pigs. A basal diet was formulated to meet current arginine requirements (0.66% - NRC, 2012) and L-arginine was supplemented at 0.3, 0.6, 0.9, and 1.2%. Experimental diets were provided in meal form during phases 1 and 2 of a 3-phase nursery feeding program: Phase 1 (d0-d7), Phase 2 (d8-d21), and Phase 3 (d22-d42). A common diet was provided during phase 3. Feed disappearance and body weight were measured at d7, 14, 21, and 42 after weaning. Through the first three weeks after weaning, increasing dietary arginine supply linearly improved (P ≤ 0.05) body weight (8.25 - 11.20 kg), average daily gain (Figure 1), average daily feed intake (251.53 - 387.75 g), and gain to feed ratio (0.60 – 0.66) of pigs. These beneficial effects persisted throughout phase 3, where arginine supplementation resulted in a linear improvement in pig overall growth performance. In addition, increasing arginine supply reduced the percentage of pigs that lost weight during the first week post-weaning by 29%. Overall, weaned pigs require more dietary arginine for optimal nursery performance, which includes reducing fall back pigs.