Exogenous carbohydrase reduced markers of intestinal and systemic immune activation and decreased Lactobacillus in weaned pigs

Authors: LI, QINGYUN - Iowa State University; SCHMITZ-ESSER, STEPHAN - Iowa State University; Loving, Crystal; GABLER, NICHOLAS - Iowa State University; GOULD, STACIE - Iowa State University; PATIENCE, JOHN - Iowa State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2018
Publication Date: 12/26/2018
Citation: Li, Q., Schmitz-Esser, S., Loving, C.L., Gabler, N.K., Gould, S.A., Patience, J.F. 2018. Exogenous carbohydrase added to a starter diet reduced markers of systemic immune activation and decreased Lactobacillus in weaned pigs. Journal of Animal Science. 97(3):1242-1253. https://doi.org/10.1093/jas/sky481.
DOI: https://doi.org/10.1093/jas/sky481

Interpretive Summary: Pork is an important protein source and is in high demand globally. The ability of pigs to grow rapidly and efficiently is impacted my many variables including diet and immune activation. The addition of different compounds to the diet serves as a method to enhance nutrient uptake from the diet of pigs, but may also alter immune activation at the gut or at the systemic level. To better understand the mechanism of improved growth of some fiber diets with and without added enzymes to enhance nutrient liberation, a study was performed to assess pig growth, feed intake, markers of peripheral inflammation, and immune status in the colon. The addition of an enzyme blend to the pig diet decreased local and systemic markers of immune activation, which may be involved in diverting energy from the immune system towards animal growth. Collectively, the results provide useful information to pork producers on methods to enhance efficiency of their production systems, and improve animal health and well-being.

Technical Abstract: It is less known how exogenous carbohydrases modulate the immune status and microbial population of pigs. This study aimed to evaluate the impact of xylanase (X) and a carbohydrase enzyme blend (EB; cellulase, beta-glucanase and xylanase) on the immune profile of the intestine and peripheral system as well as intestinal microbes and microbial metabolites of weaned pigs fed higher fiber diets. Pigs (n equals 460; 6.43 plus or minus 0.06 kg BW; F25 times 6.0 Genetiporc) were blocked by initial BW and 48 pens (n equals 12 per treatment) were randomly assigned to 1 of 4 dietary treatments, including a higher fiber control diet (CON) and the CON supplemented with 0.01 percent X, 0.01 percent EB, or both enzymes (X plus EB), arranged in a 2 times 2 factorial. The diets were based on corn, soybean meal, corn distillers dried grains with solubles (DDGS), and wheat middlings. After a 7-d adaptation period, pigs were fed experimental diets ad libitum for 28 d. Blood samples were collected from one pig per pen on d 0, 7, 14, and 28. Intestinal tissues and digesta were collected on d 28. A significant X times EB interaction was observed for interleukin (IL) -17 and IL-6 mRNA levels (P less than 0.05), such that EB increased their abundance when X was present, but not when X was absent. The main effect of X decreased IL-1 beta and EB reduced IL-8 in the plasma over the 28-d trial (P less than 0.05). There was an X times EB interaction on IL-1 beta and tumor necrosis factor (TNF) -a (P less than 0.05); their concentration was decreased when X and EB were added together, but not individually, compared to CON. The EB decreased cecal propionate, butyrate, and total volatile fatty acids (VFA; P less than 0.05). In the colon, EB decreased propionate when X was absent (P less than 0.05), but not when X was present. The main effect of X decreased ileal Lactobacillus and increased ileal and cecal Enterobacteriaceae (P less than 0.05). Pigs fed diets with EB had decreased colonic Lactobacillus (P less than 0.05) and a tendency (P equal 0.065) for decreased Enterobacteriaceae compared to diets without EB. In conclusion, exogenous carbohydrase supplementation decreased local and systemic markers of immune activation, potentially diverting energy and nutrients away from immune systems and towards growth . The EB reduced relative abundance of Lactobacillus and Enterobacteriaceae as well as total VFA in the large intestine, probably due to accelerated starch removal and fiber degradation in the small intestine and thus reduced substrate availability in the large intestine.