Replacing Dietary Antibiotics with 0.20% L-Glutamine in Swine Nursery Diets: Impact on Health and Productivity of Pigs Following Weaning and Transport

May 29, 2019 — 

Antibiotic use has been limited in United States swine production. Therefore, the objective was to determine whether supplementing L-glutamine at cost-effective levels can replace dietary antibiotics to improve piglet welfare and productivity following weaning and transport. Based on previous research, we hypothesized that withholding dietary antibiotics would negatively affect pigs while diet supplementation with 0.20% L-glutamine (GLN) would have similar effects on pig performance and health as antibiotics. Mixed sex piglets (N = 480; 5.62 ± 0.06 kg BW) were weaned (18.4 ± 0.2d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pigs were blocked by BW and allotted to 1 of 3 dietary treatments [n = 10 pens/dietary treatment/replicate (8 pigs/pen)]; antibiotics [A; chlortetracycline (441 ppm) + tiamulin (38.6 ppm)], no antibiotics (NA), or GLN fed for 14 d. On d 15 to 34, pigs were provided common antibiotic free diets in two phases. Data were analyzed using PROC MIXED in SAS 9.4. Day 14 BW and d 0 to 14 ADG was greater (P = 0.01) for A (5.6 and 18.5%, respectively) and GLN pigs (3.8 and 11.4%, respectively) compared to NA pigs, with no differences between A and GLN pigs. Day 0 to 14 ADFI increased for A (P < 0.04; 9.3%) compared to NA pigs; however, no differences were detected when comparing GLN to A and NA pigs. Once dietary treatments ceased, no differences (P > 0.05) in productivity between dietary treatments were detected. On d 13, plasma tumor necrosis factor alpha (TNF-α) was reduced (P = 0.02) in A (36.7 ± 6.9 pg/ml) and GLN pigs (40.9 ± 6.9 pg/ml) versus NA pigs (63.2 ± 6.9 pg/ml). Aggressive behavior tended to be reduced overall (P = 0.09; 26.4%) in GLN compared to A pigs, but no differences were observed between A and GLN versus NA pigs. Huddling, active, and eating/drinking behaviors were increased overall (P < 0.02; 179, 37, and 29%, respectively) in the spring replicate compared to the summer replicate. When hot carcass weight (HCW) was used as a covariate, loin depth and lean percentage was increased (P = 0.01; 4.0% and 1.1%, respectively) during the spring replicate compared to the summer replicate. In conclusion, GLN supplementation improved pig performance and health after weaning and transport similarly to A across replicates; however, the positive effects of A and GLN were diminished when dietary treatments ceased.

Duttlinger AW, Kpodo KR, Lay DC, Richert BT, Johnson JS. Replacing dietary antibiotics with 0.20% L-glutamine in swine nursery diets: Impact on health and productivity of pigs following weaning and transport. J Anim Sci. 2019 Mar. https://doi.org/10.1093/jas/skz098