Replacing Dietary Antibiotics with L-Glutamine Following Weaning and Transport in Swine
Abstract
In recent years, U.S. swine producers have received pressure from consumers to reduce antibiotic usage. With the increased consumer pressure, pork producers have sought out other technologies, including feed additives, to reduce antibiotic usage in commercial pork production. Therefore, the objective of Chapter 2 was to determine whether supplementing L-glutamine at cost-effective levels can replace dietary antibiotics to improve pig 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% Lglutamine (GLN) would have similar effects on pig performance and health as antibiotics. Mixed sex pigs (N = 480; 5.62 ± 0.06 kg BW) were weaned (18.4 ± 0.2 d 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 were 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 comparing GLN to A and NA pigs. Once dietary treatments ceased, no differences (P > 0.05) in growth performance among 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. A subset of pigs from Chapter 2 were utilized, in Chapter 3, to evaluate the dietary treatment effects on intestinal morphology and gene expression. On d 33, mast cells/mm2 were increased (P = 0.05) in GLN and NA pigs vs. A pigs (22.2% and 19.7%, respectively). On d 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and A pigs vs. NA pigs. On d 33, glucagon-like peptide 2 ((GLP-2)) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. A pigs. Crypt depth was increased (P = 0.01; 16.2%) and villus height:crypt depth ratio was reduced (P = 0.01; 9.6%) during the spring replicate compared to the summer replicate on d 33.
Degree
Ph.D.
Advisors
Johnson, Purdue University.
Subject Area
Energy|Animal sciences|Bioinformatics|Endocrinology|Genetics|Microbiology|Pharmaceutical sciences
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.