Effects of dietary supplementation of montmorillonite and yeast cell wall on lipopolysaccharide adsorption, nutrient digestibility and growth performance in beef cattle

The study was carried out to evaluate the effects of dietary supplementation of montmorillonite (MMT) and yeast cell wall (YCW) on lipopolysaccharide (LPS) adsorption, apparent nutrient digestibility and growth performance in beef cattle. Eighteen beef steers (Simmental×Luxi) with an initial body weight (means±standard deviation) of 335±7.5 kg and similar body condition were randomly assigned to one of three treatments for 50 days in a completely randomized design. The treatments consisted of (1) the basal diet (control), (2) the basal diet+2 g/kg MMT, and (3) the basal diet+2 g/kg YCW on a dry matter basis. Fecal grab samples were collected for five consecutive days on days 41-45 after the morning feeding; jugular vein blood was collected on day 45 before the morning feeding, and beef steers were slaughtered at the end of the 50-day trial and dissected to collect samples of ruminal fluid and digesta of different intestinal sectors (the duodenum, jejunum, ileum, cecum and colon). Results showed that dietary MMT supplementation decreased (P<0.05) free LPS concentrations in plasma, feces, and the digesta of different sectors of the gastrointestinal tract except the cecum. Dietary YCW supplementation decreased (P<0.05) free LPS concentrations in plasma, feces, and the digesta of the lower gut including the ileum, cecum and colon. Correspondingly, the levels of acute phase proteins (serum amyloid-A, haptoglobin, C-reactive protein, and LPS-binding protein) in plasma were also decreased (P<0.05) by dietary supplementation of MMT and YCW. Dietary supplementation of YCW increased (P<0.05) apparent digestibilities of acid detergent fiber and total phosphorus and improved (P<0.05) average daily gain and feed efficiency. Dietary supplementation of MMT only improved feed efficiency (P<0.05). Results suggest dietary supplementation of MMT and YCW can effectively bind LPS in the digestive tract, reduce the translocation of LPS from the digestive tract into the circulation, and thus improve growth performance in beef cattle. Dietary supplementation of YCW at a dose of 2 g/kg was more effective than that of MMT at the same dose in reducing plasma acute phase protein levels and in improving growth performance.