Abstract
A study was conducted to determine the effects of two prebiotic blends on the acute phase response (APR) following lipopolysaccharide (LPS) challenge in steers. Crossbred steers (n = 36; 273±4 kg) were fed for 21d on three different treatments: 1) Control, fed a standard receiving ration; 2) Control ration supplemented with a Prebiotic/Probiotic blend (28.4 g/hd/d; PMI); and 3) Control ration supplemented with a DFM/Prebiotic blend (19.0 g/hd/d; PMI). On d20, calves were fitted with indwelling rectal temperature (RT) monitors and jugular catheters and moved into individual stanchions in a covered barn. On d21, blood samples were collected, and sickness behavior scores recorded at 0.5-h intervals from -2 to 8h and again at 24h relative to an i.v. challenge with 0.25 µg/kg BW LPS. Serum was isolated and stored until analyzed for pro-inflammatory cytokines, cortisol and glucose concentrations. Complete blood counts were measured every 2h from -2 to 8h and again at 24h. Pre-challenge RT measured for 18h prior to the challenge tended (P = 0.10) to be affected by treatment such that calves fed the Prebiotic/Probiotic blend had greater RT than Control and tended to be greater than calves fed the DFM/Prebiotic blend (38.9, 39.2, and 39.0±0.1oC, respectively). Post-challenge RT increased 0.8–1.0oC on average but did not differ between treatments (P = 0.53). Sickness behavior scores were not different between treatments (P = 0.14). There were no differences in white blood cell or differential counts between treatments (P ≥ 0.25). Serum concentrations of TNF-α, IL-6, and IFN-γ increased in response to the challenge (P < 0.01) but were not different between treatments (P ≥ 0.26). Serum cortisol and glucose concentrations were reduced in both supplemented groups compared to Control steers (P ≤ 0.006). Therefore, the data suggest that the effects of the prebiotic blends during an immune challenge were limited to alterations in metabolic biomarkers and energy utilization.
Carotenoids buffer the acute phase response on fever, sickness behavior and rapid bill color change in zebra finches