|Carroll, Jeffery - Jeff Carroll|
|Chapman, James - Prince Agri Products, Inc|
|Welsh Jr., Thomas - Texas Agrilife Research|
|Vann, Rhonda - Mississippi State University|
|Randel, Ronald - Texas Agrilife Research|
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., Carroll, J.A., Chapman, J.D., Welsh Jr., T.H., Vann, R.C., Randel, R.D. 2012. OmniGen-AF supplementation modulated the physiological and acute phase responses of Brahman heifers to an endotoxin challenge [abstract]. Journal of Animal Science. 90:221(E-Suppl. 3).
Technical Abstract: This study examined the effect of feeding OmniGen-AF (OG; Prince Agri Products) on the physiological and acute phase responses (APR) of newly-weaned heifers to an endotoxin (lipopolysaccharide; LPS) challenge. Brahman heifers (n=24; 183±5 kilograms) from the Texas AgriLife Research Center in Overton, TX, were separated into 2 groups at weaning: 1) Control (C; n=12) and 2) OG (n=12; fed at 4 grams per 45.4 kilograms body weight) and fed for 69 days. On day 35 heifers were fitted with indwelling vaginal temperature (VT) monitoring devices, and were transported from Overton to New Deal, TX, on day 39. On day 40, heifers were fitted with indwelling jugular catheters and moved into a barn with individual stalls. On day 41, heifers were challenged with LPS (0.25 microgram/kilogram body weight intravenously) and blood samples were collected at 0.5 hour intervals from -2 to 8 hour and again at 24 hour relative to LPS challenge (0 hour). Additional blood samples were collected every 2 hours and analyzed for white blood cell (WBC) counts. Sickness behavior scores (SBS) were assigned following collection of each sample. Serum was isolated and analyzed for cortisol, interleukin-6 (IL6), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) concentrations. Heifers were transported back to Overton on day 43. Post-LPS VT increased (P<0.01) in all heifers, and was lower in OG (38.97±0.01C) than C heifers (39.03±0.00C; P<0.01). Post-LPS SBS increased (P<0.01) and were greater in OG (2.34±0.02) than C heifers (2.16±0.02; P<0.01). Cortisol concentrations increased post LPS (P<0.01) and were greater in OG (54.8±1.1 ng/mL) than C heifers (48.4±1.1 ng/mL; P<0.01). Pre- and post-LPS WBC and lymphocytes (L) were greater in OG (WBC: 147±4 and 82±2 cells/microliter; L: 90±3 and 42±2 cells/microliter) than C heifers (WBC: 110±4 and 63±2 cells/microliter; L: 68±3 and 35±1 cells/microliter; P<0.01). Total WBC, L, and neutrophils decreased 1 h post LPS (P<0.01). Although post-LPS IFN-gamma, TNF-alpha and IL6 increased (P<0.01), there was no treatment effect (P>0.51). These data suggest that OG-supplemented heifers were primed to produce a quicker APR to LPS challenge (lower VT, greater WBC counts), allowing for the heifers to recover quicker than C heifers.