Effects of fermented soybean meal on immune response of weaned calves with experimentally induced lipopolysaccharide challenge

Abstract

The present study was conducted to evaluate the effects of fermented soybean meal (FSBM) on the level of cortisol hormone and immune-related serum proteins in weaned calves after experimentally induced lipopolysaccharide (LPS) challenge. Holstein neonatal calves (n=21; 8 males and 13 females, BW=42.2±6.15 kg) were randomly allocated to one of two dietary treatments: SBM (control calf starter having soybean meal (SBM) as a main protein source) and FSBM (substitute SBM in control diet with FSBM) groups. All calves were fed milk replacer using an automatic milk-feeder according to step-down milking method and weaned at 7 weeks old. Experimental diets were given to calves ad libitum throughout the experimental period. For LPS challenge, all calves except negative control animals given phosphate buffered saline (PBS), were injected subcutaneously with Salmonella typhimurium LPS on day 7 (D7) after weaning (D0). No significant difference in growth performance and milk intake was observed between SBM and FSBM calves. Feeding FSBM diet resulted in significantly (p<0.05) higher LPS-specific IgG at D12 and D19 and LPS-specific IgA at D19 in peripheral blood. Calves fed with FSBM diet also had significantly (p<0.05) higher concentration of serum haptoglobin (Hp) at D8. Overall concentration of cortisol in FSBM group was considerably lower than that of SBM group. Results from current study indicate that FSBM may provide beneficial effects in alleviating weaning stress and enhance immune status of weaned calves.