Effects of dietary supplementation of glutamine and mannan oligosaccharides on plasma endotoxin and acute phase protein concentrations and nutrient digestibility in finishing steers

Abstract

This study was conducted to investigate the effects of dietary supplementation of glutamine (Gln) and mannan oligosaccharides (MOS) on plasma endotoxin and acute phase protein concentrations and nutrient apparent digestibility in finishing steers. Eighteen Simmental×Luxi crossbred finishing steers were randomly and evenly divided into three treatments: (1) the basal diet (control); (2) the basal diet + 1% Gln; (3) the basal diet + 0.2% MOS. The results showed: dietary supplementation of Gln decreased the plasma and fecal lipopolysaccharide (LPS) by 7.10% and 12.49%, respectively, but the differences did not attain statistical significance (P>0.05). The plasma concentrations of haptoglobin (Hp), serum amyloid A (SAA), and C-reactive protein (CRP) were not affected (P>0.05), but the plasma concentration of LPS binding protein (LBP) was increased (P<0.01). Dietary supplementation of MOS decreased (P<0.05) the plasma and fecal LPS contents by 10.43% and 18.35%, respectively, and reduced the plasma contents of Hp, SAA, CRP, and LBP by 95.65% (P<0.05), 85.88% (P<0.05), 50.63% (P<0.05), and 46.80% (P>0.05), respectively. Dietary supplementation of Gln and MOS had no effects on nutrient apparent digestibility (P>0.05). Overall, MOS is more effective than Gln in decreasing the concentrations of LPS in plasma and feces, and the plasma acute phase proteins are affected in different manners by Gln and MOS supplementation.