The effect of pain relief at castration on piglet performance

The objective of this study was to determine if piglet performance could be improved by using analgesia during castration. Male piglets between 5 and 7 d of age were ear notched, weighed, then randomly selected into control (n = 700) and treatment (n = 700) groups and given an injection (IM) of either saline solution or Ketoprofen injection (100 mg/mL 1 mL/50 kg body weight), respectively. Piglets were then castrated 30 min after receiving the injection, and 10 min after castration piglets were observed for signs of discomfort. A final weight was taken at 21 d of age, and mortality was recorded.

Results (to date) demonstrate no apparent difference in both the ADG and mortality of male piglets in both the control (n = 410) and treatment (n = 416) groups. No difference was noted in post-castration behaviour between the groups. The use of analgesia increased the time to castrate and cost $0.22/piglet.

Based on these preliminary data and data from previous studies, there does not appear to be an economic benefit from providing analgesia to piglets at castration. Previous work involving the use of either local or general anaesthetics at the time of castration do not alter weight gain, have not proven to lower cortisol levels and are associated with higher mortality rates. In the case of general anaesthetics, there are increased time and monetary costs when compared to the use of ketoprofen. Further analysis or future studies might show that in specific cases such as castrating low weight piglets, the use of an intramuscular analgesic, such as ketoprofen, may be warranted from a performance standpoint.