Prebiotics and β‐Glucan Affect Jejunal and Serum Alkaline Phosphatase Affinity in Weanling Pigs

Abstract

Biological mechanisms of dietary supplementation of prebiotics and β‐glucan in modulation of health status need further clarification. Given the recognized role of alkaline phosphatases (AP) in detoxification of endotoxin lipopolysaccharides (LPS), we hypothesized that dietary supplementation of three prebiotics and β‐glucan in modulation of health status was mediated through affecting alkaline phosphatase functionality such as maximal enzyme activity (Vmax) and enzyme affinity (Km). This study was conducted to determine effects of dietary supplementation of three prebiotics and β‐glucan at 0.75% instead of feed antibiotics on growth performance, blood urea concentration, fecal scores, jejunal and serum AP kinetics and large intestinal fermentation in weanling piglets fed corn and soybean meal (SBM)‐based diets. Six experimental diets were formulated with corn, SBM and fishmeal as the bulk ingredients. This includes Diet 1, a negative control (NC) of the basal diet with no supplemental feed antibiotics and no tested supplements; Diet 2, a positive control (PC) of the basal diet with supplemental feed antibiotics but no other tested supplements; Diet 3, a retrograded resistant corn starch supplementation of the basal diet with no supplemental feed antibiotics; Diet 4, an oat β‐glucan supplementation of the basal diet with no supplemental feed antibiotics; Diet 5, a Fibersol‐2 supplementation of the basal diet with no supplemental feed antibiotics; and Diet 6, an inulin supplementation of the basal diet with no supplemental feed antibiotics. A total of 216 piglets, 21 d old, with an initial body weight of 7.0 kg, were fed 1 of the 6 diets for 21 d in three study blocks according to a completely randomized block design. Dietary supplementation of the three prebiotics and β‐glucan did not significantly affect growth performance and main intestinal fermentation endpoints. Dietary supplementation of β‐glucan in Diet 4 increased (P<0.05) the wk 1–3 overall fecal score compared with the NC diet. Fibersol‐2 in Diet 5 and inulin in Diet 6 reduced (P<0.05) the Vmax of the proximal jejunal AP compared with the NC diet. The Vmax of serum AP was different (P<0.05) between the β‐glucan Diet 4 and the PC diet. Dietary supplementation of Fibersol‐2 in Diet 5 and β‐glucan in Diet 4 increased the AP affinity by about 1 fold compared with the NC diet. Serum AP affinity Km values were at least 10‐fold higher than the Km values of the jejunal AP, suggesting that the proximal jejunal AP is potentially much more efficient than the serum AP in detoxification of endotoxin LPS. Dietary supplementation of the three prebiotics and oat β‐glucan at 0.75% had little effects on growth performance but might affect the gut and whole body health status via influencing the AP detoxification kinetics in the weanling pig.Support or Funding InformationSupported by the NSERC Discovery and the OMAFRA‐University Partnership Programs.