|WORD, ALYSSA - Texas Tech University|
|SHARON, KATE - Texas Tech University|
|ROBERT, SHELBY - West Texas A & M University|
|RICHESON, JOHN - West Texas A & M University|
|DEFOOR, PAUL - Cactus Feeders, Inc|
|CRAVEY, MATT - Phileo Lesaffre Animal Care|
|CORLEY, JIMMIE - Phileo Lesaffre Animal Care|
|BALLOU, MICHEAL - Texas Tech University|
|Carroll, Jeffery - Jeff Carroll|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 4/21/2016
Publication Date: 7/1/2016
Citation: Word, A.B., Broadway, P.R., Sanchez, N.C., Sharon, K.P., Robert, S.L., Richeson, J.T., Defoor, P.J., Cravey, M.D., Corley, J.R., Ballou, M.A., Carroll, J.A. 2016. Yeast supplementation altered the metabolic response to a combined viral-bacterial challenge in feedlot heifers. Journal of Animal Science Supplement. 94(E-Supplement 5):516-517, Abstract#1098.
Technical Abstract: Two treatments were evaluated in feedlot heifers to determine the effects of feeding a yeast supplement on metabolic responses to a combined viral-bacterial respiratory disease challenge. Thirty-two beef heifers (325 +/- 19.2 kg) were selected and randomly assigned to one of two treatments: 1) Control (CON), receiving a standard feedlot ration with no yeast supplement, or 2) yeast, (YEAST) control ration plus a combination live yeast (2.5 g'hd-1'd-1) and yeast cell wall (2.5 g'hd-1'd-1) supplement (Phileo-Lesaffre, Milwaukee, WI). Cattle were maintained on treatments for 31 d. On d -3 all cattle were challenged intra-nasally with 1x10^8 PFU of bovine herpesvirus-1 (BHV-1) and then allowed to rest in outdoor pens for 3 d. On d 0, each heifer was challenged intra-tracheally with approximately 3x10^7 CFU of Mannheimia haemolytica, was fitted with an indwelling jugular catheter and indwelling vaginal temperature recording device, and was moved into individual stanchions in an environmentally-controlled barn. Whole blood samples were collected at the time of BHV-1 challenge, at 1-h (serum) or 2-h (complete blood cell counts) intervals from 0 to 8 h, and at 12, 24, 36, 48, 60, and 72 h following the M. haemolytica challenge. Data were analyzed using the mixed procedure of SAS specific for repeated measures with fixed effects of treatment, time, and their interaction. Cattle in the YEAST group had a greater glucose concentration following M. haemolytica challenge (121.38 +/- 2.91 vs. 109.86 +/- 2.90 mg/dL, respectively; P < 0.01) and decreased serum concentrations of blood urea nitrogen compared to CON (11.82 +/- 0.53 vs. 10.12 +/- 0.53 mg/dL, respectively; P = 0.03). There was no difference in serum NEFA concentration between YEAST (0.14 +/- 0.01 mg/dL) and CON (0.15 +/- 0.01mg/dL; P = 0.37). These data indicate that feeding a combination live yeast and yeast cell wall product may modulate energy stores by reducing muscle catabolism to provide energy for the activated immune system in response to a respiratory disease challenge. This reduced catabolism has the potential to extrapolate to an improvement in live animal performance when an animal is exposed to respiratory disease.