|Cribbs, Joshua - Texas Tech University|
|Carroll, Jeffery - Jeff Carroll|
|Schmidt, Ty - Mississippi State University|
|Johnson, Bradley - Texas Tech University|
|Rathmann, Ryan - Texas Tech University|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2012
Publication Date: 6/25/2012
Citation: Sanchez, N.C., Cribbs, J., Carroll, J.A., Callaway, T.R., Schmidt, T.B., Johnson, B.J., Rathmann, R.J. 2012. Dried citrus pulp modulates the physiological and acute phase responses of crossbred heifers to an endotoxin challenge [abstract]. Journal of Animal Science. 90:513(Suppl. 3).
Technical Abstract: This study examined the effect of feeding dried citrus pulp (CP) pellets on the physiological and acute phase responses (APR) of newly-received crossbred heifers to an endotoxin (lipopolysaccharide; LPS) challenge. Heifers (n=24; 218.3±2.4 kg) were obtained from commercial sale barns and transported to the Texas Tech University Beef Center. Heifers were separated into treatment groups receiving a Control Diet (C; n=8), CP10 (10% CP DM basis; n=8) or CP20 (20% CP DM basis; n=8) and were fed for 65d while being systematically stepped up to a finishing ration. On d63, heifers were fitted with indwelling vaginal temperature (VT) recording devices and jugular catheters and moved into a barn with individual stalls. On d64, heifers were challenged i.v. with LPS (0.5 ug/kg BW) and blood samples were collected every 0.5 h from -2 to 8 and again at 24h relative to LPS challenge (0h). Sickness behavior scores (SBS) were also assigned following collection of each blood sample. Serum was isolated and stored at -80C until analysis for cortisol, interleukin-6 (IL6), interferon-gamma (IFNgamma), and tumor necrosis factor-alpha (TNFalpha) concentrations. Pre-LPS VT were lower in CP10 (38.44±0.02C) than C (38.74±0.02C) and CP20 treatments (38.68±0.02C; P<0.01). There was an increase in VT in all treatments post-LPS (P<0.001), with CP10 (38.69±0.02C) maintaining lower VT post-LPS than C (38.98±0.02C) and CP20 treatments (38.97±0.02C; P <0.01). Post-LPS SBS increased (P<0.01) and were greater in CP10 (1.14±0.02) than CP20 (1.09±0.02) and C (1.03±0.02; P<0.01). Post-LPS cortisol concentrations were greatest in CP10 (68.1±2.1 ng/mL) heifers than C (60.9±2.0 ng/mL) or CP20 treatments (59.5±1.9 ng/mL; P<0.01). Concentrations of IFNgamma, TNFalpha, and IL6 increased post-LPS (P<0.01) and were greater in CP20 (24.6±1.1, 123.03±11.1, and 2370±123 pg/mL, respectively) than CP10 (16.9±1.0, 91.3±11.1, and 1981±124 pg/mL, respectively) and C treatments (12.2±0.9, 19.1±10.2, and 1175±104 pg/mL, respectively; P<0.01). These data indicate that CP inclusion in the diet can modulate both the physiological and APR of newly-received heifers to an endotoxin challenge.