Figure 4.

Effect of yeast supplementation on serum glucose response in beef heifers (n = 16/trt). Heifers were fed one of two dietary treatments: 1) negative control (CON), fed a standard feedlot diet, or 2) the same standard feedlot diet with 2.5 g·heifer⁻¹·d⁻¹ live yeast and 2.5 g·heifer⁻¹·d⁻¹ yeast cell wall product (Phileo Lesaffre Animal Care, Milwaukee, WI) for 31 d prior to challenge (YST). Data presented as least squares means ± SEM and 0 h was used as a covariate in the analysis. All heifers were challenged intranasally with 2 × 10⁸ plaque-forming units bovine herpesvirus-1 (BHV-1) at −144 h and 3 × 10⁷ colony-forming units Mannheimia haemolytica at 0 h. There was a tendency for a treatment × time interaction (P = 0.04) such that CON heifers had decreased serum glucose at 1 h and remained so until 6 h following BHV-1/M. haemolytica. Serum glucose was similar between dietary treatments (P = 0.25).