|Carroll, Jeffery - Jeff Carroll|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/12/2012
Publication Date: 6/25/2012
Citation: Sanchez, N.C., Young, T.R., Carroll, J.A., Corley, J.R., Rathmann, R.J., Johnson, B.J. 2012. The effect of yeast cell wall supplementation on the physiological and acute phase responses of crossbred heifers to endotoxin challenge [abstract]. Journal of Animal Science. 90:221(E-Suppl. 3). Interpretive Summary:
Technical Abstract: A study was conducted to determine the effect of feeding yeast cell wall (YCW) products on the physiological and acute phase responses of crossbred newly-received heifers to endotoxin (lipopolysaccharide; LPS) challenge. Heifers (n=24; 218.9+/-2.4 kg) were obtained from commercial sale barns and transported to the Texas Tech University Beef Center in New Deal, Texas. Heifers were separated into treatment groups receiving a Control Diet (C; n=8), YCW A (2.5 g/hd/d; n=8) or YCW C (2.5 g/hd/d; n=8) and were fed for 52 days. On day 36, heifers were fitted with indwelling vaginal temperature (VT) recording devices and jugular catheters and moved into a barn with individual stalls. On day 37, heifers were challenged intraveneously with LPS (0.5 microgram/kg body weight) and blood samples were collected every 0.5 hour from -2 to 8 hour and again at 24 hour relative to LPS challenge (0 hour). Sickness behavior scores (SBS) were assigned following collection of each blood sample. Serum was isolated and stored at -80C until analyzed for cortisol, interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) concentrations. There was an increase in VT in all treatments post-LPS (P<0.001), with YCW C (38.90±0.03C) maintaining lower VT post-LPS than C (39.00±0.3C) and YCW A treatments (38.99±0.03C; P <0.01). Although low, post-LPS SBS increased but were not affected by treatment (P=0.54). Cortisol concentrations were greatest in C (39.7±1.5 ng/mL) heifers post-LPS than YCW A (31.3±1.7 ng/mL) or YCW C treatments (32.0±1.7 ng/mL; P<0.001). Concentrations of IFN-gamma and TNF-alpha increased post-LPS (P<0.001) but were not affected by treatment (P = 0.50 and 0.35, respectively). Serum IL-6 concentrations increased post-LPS (P<0.001) and were greater in C (351.5±36.0 pg/mL) heifers than YCW A (85.8±42.9 pg/mL) and YCW C (136.2±36.0 pg/mL; P<0.001) heifers. These data indicate that YCW supplementation can decrease the physiological and acute phase responses of newly-received heifers to endotoxin challenge. Therefore, YCW supplementation may be a viable feed supplement for newly-received heifers in order to reduce the negative effects of illness.