Location: Livestock Issues ResearchTitle: Effect of castration timing and oral meloxicam administration on growth performance, inflammation, behavior and carcass quality of beef calves Author
|Brown, April - University Of Arkansas|
|Powell, Jeremy - University Of Arkansas|
|Kegley, Elizabeth - University Of Arkansas|
|Gadberry, M - University Of Arkansas|
|Reynolds, Jana - University Of Arkansas|
|Hughes, Heather - West Texas A & M University|
|Carroll, Jeffery - Jeff Carroll|
|Thaxton, Yvonne - University Of Arkansas|
|Richeson, John - West Texas A & M University|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/13/2015
Publication Date: 5/18/2015
Citation: Brown, A.C., Powell, J.G., Kegley, E.B., Gadberry, M.S., Reynolds, J.L., Hughes, H.D., Carroll, J.A., Sanchez, N.C., Thaxton, Y.V., Richeson, J.T. 2015. Effect of castration timing and oral meloxicam administration on growth performance, inflammation, behavior and carcass quality of beef calves. Journal of Animal Science. 93:2460-2470.
Interpretive Summary: Approximately 15 million bull calves are castrated annually in the US. While castration is necessary to reduce undesirable aggressive and breeding behavior, and to improve meat quality, various castration procedures have been shown to cause pain, stress and inflammatory responses. The American Veterinary Medical Association encourages the reduction or elimination of pain during routine management practices such as dehorning and castration. However, there are currently no pharmaceutical drugs approved by the Food and Drug Administration for analgesia in beef cattle. Meloxicam, a non-steroidal anti-inflammatory drug, is however approved by the Food and Drug Administration and prescribed for analgesia in other species. Therefore, a collaborative study was conducted by scientists from the University of Arkansas, West Texas A&M University, and ARS' Livestock Issues Research Unit to evaluate whether or not meloxicam would improve gain performance, and alter behavior and inflammatory variables following castration in neonatal calves or in weaned beef calves. The results from this study indicated that surgical castration performed near birth with or without meloxicam had no effect on growth and very little impact on behavior or inflammation in crossbred beef calves. These data also indicate that utilizing meloxicam during surgical castration in older calves at weaning mitigated the acute phase response and briefly improved post-castration average daily gain. Therefore, use of analgesia during surgical castration of weaning-age calves should be considered as a potential tool for reducing pain and inflammation associated with castration. This information will be of interest to beef producers, veterinarians, and researchers working in the fields of animal health and well-being.
Technical Abstract: Beef bull calves (n = 62) were assigned randomly, within sire breed, to 1 of 4 treatments at birth. Treatments were: 1) surgical castration near birth, 2) surgical castration near birth with oral administration of meloxicam (1 milligram/kilogram of body weight), 3) surgical castration at weaning (WNG), or 4) surgical castration at weaning with oral administration of meloxicam (1 milligram/kilogram of body weight; WMX). A subset of calves (n = 7/treatment group) were selected randomly near birth for blood collection, behavioral analyses, and rectal temperature (RT) records for a 7-day post-castration period on day 0 (birth), 1, 3 and 7, and on day 214 (weaning), 214 + 6 hours, 215, 217, 221 and 228. Calf standing and lying activity was monitored from the same subsets by recording x and y axis positions of an accelerometer attached to the right metatarsus for 7-days post-castration. Periodically, body weight was recorded throughout the entire production cycle, and carcass data were collected at slaughter. For statistical analyses, bulls left intact at birth were considered a positive control (BUL) 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. No difference (P = 0.88) occurred in average daily gain between treatments throughout the pre-weaning period (day 0 to 214); however, 56-day post-weaning average daily gain was greatest (P = 0.02) in STR, intermediate in WMX, and least in WNG. At weaning, haptoglobin (Hp) was greater (P = 0.005) for WNG and WMX compared to STR on days 214+6 hours, 215, and 217, and Hp was greater (P = 0.05) in WNG compared to WMX on day 217. Neutrophils increased (P < 0.001) and red blood cells decreased (P = 0.03) for WNG and WMX on day 214+6 h and 217, respectively. Post-weaning behavior observations indicated that STR calves spent the least proportion of time standing (P = 0.002) when compared to WNG and WMX. Furthermore, WMX calves exhibited a greater proportion of time spent standing (P = 0.03) compared to WNG. Grazing and finishing phase average daily gain and carcass measurements did not differ (P = 0.24) across treatments. In this study, surgical castration at weaning, but not near birth, altered the acute phase response, behavior and growth performance. Oral meloxicam reduced serum Hp and improved average daily gain briefly when administered to calves castrated at weaning. Oral administration of meloxicam may be efficacious for mitigating some of the stress and inflammation associated with castration of weaning-age bull calves.