Location: Livestock Issues ResearchTitle: Effect of surgical castration of bull calves at different stages of maturity with or without analgesia on the acute phase response (APR) and complete blood count (CBC) Author
|Carroll, Jeffery - Jeff Carroll|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/12/2013
Publication Date: 10/24/2013
Citation: Hughes, H.D., Powell, J.G., Kegley, E.B., Brown, A.C., Sanchez, N.C., Carroll, J.A., Richeson, J.T. 2013. Effect of surgical castration of bull calves at different stages of maturity with or without analgesia on the acute phase response (APR) and complete blood count (CBC). Journal of Animal Science Supplement. 91(E-Suppl. 2): 378-379 (Abstract 282). Interpretive Summary:
Technical Abstract: The study objective was to determine if surgical castration at birth or weaning impacts the acute phase response (APR) or complete blood counts (CBC) and whether concurrent administration of an oral analgesic (meloxicam) ameliorates inflammation. Bull calves (n=29) from the University of Arkansas research herd were assigned to treatment at birth, moved with their dam into pens for 7-d, and returned to pasture until weaning on day 214. Treatments included: 1) castration near birth (BTH), 2) castration near birth with oral administration of meloxicam (1 mg/kg body weight; BMX), 3) castration at weaning (WNG), or 4) castration at weaning with oral administration of meloxicam (1 mg/kg body weight; WMX). For statistical analyses, bulls left intact at birth were considered a positive control for observations that occurred before their treatment application at weaning; likewise, bulls castrated at birth were considered a negative control (STR) during post-weaning observations. Blood samples were collected from the jugular vein on day 0 (birth), 1, 3, 7, 214 (weaning), 214+6 hours, 215, 217, 221, and 228. Whole blood was analyzed for CBC using an automated hemocytometer. Serum was analyzed for concentrations of interleukin-6 (IL6), interferon-gamma, tumor necrosis factor-alpha, and haptoglobin (Hp) using an enzyme-linked immunosorbent assay. The APR was not affected by treatment near birth; however, an overall decrease (day effect; P<0.001) in IL6 was observed between birth and d 7. At weaning, Hp was greater (P=0.005) for castrates compared to STR on day 214+6 hours, 215, and 217 and was greater (P=0.05) in WNG vs. WMX on day 217. Neutrophils (NEU) increased (P<0.001) and red blood cells decreased (P=0.03) for castrates on d 214+6 hours and 217, respectively, whereas WMX tended (P=0.10) to have lower NEU than WNG on day 215. Castration at weaning, but not near birth, altered immune parameters. Oral meloxicam reduced serum Hp when administered to calves castrated at weaning, but not in calves castrated near birth. Therefore, oral administration of meloxicam may be efficacious when surgically castrating older bull calves at or beyond the typical weaning age.