In a paper delivered to the University of Guelph Swine Research Day entitled 'The effect of pain relief at castration and farrowing on piglet performance" by S. Taylor, R. Friendship and G. Cassar, the subject of castration of piglets without the use of anaesthesia or analgesia was examined.

To date, there have been few research studies that evaluated the use of analgesia for this procedure and whether pain relief might be associated with improved piglet performance.

A second part of the same study was directed at whether there was any economic benefit or reduction in still births or perinatal death losses if sows receive medication to reduce the pain associated with farrowing. In the castration study male piglets were randomly sorted into a control group or a treatment group at five to seven days of age. Piglets were ear-notched for identification purposes, and weighed. The procedure was that they received a saline injection or Anafen® (Ketoprofen injection 100 mg/mL, 1mL/50 kg body weight, respectively). Piglets were castrated 30 minutes after receiving the injection, and observations were made 10 minutes after castration for signs of discomfort. Piglets were weighed at 21 days of age, and mortality was recorded.

In the sow study, sows were randomly assigned to a control group or a treatment group. The treatment group received an IM injection of 1 mL/50kg body weight of Anafen prior to farrowing and again the day of farrowing. Piglets from both control and treated sows were ear- notched and weighed on the day of farrowing and day 21, and pre weaning mortality was recorded.

Castration trial results to date showed no apparent difference in both the average daily gain and pre-weaning mortality of male piglets in both the control and treatment groups. No difference was noted in post castration behaviour between the two groups. The cost of analgesia was $0.22 per piglet and it did increase the time to castrate.

The farrowing trial showed no differences between stillbirth rate, weaning weights or pre-weaning mortality between treated and control animals. The cost of Ketoprofen was 13.05/sow/dose.

These preliminary data indicate no economic benefit from providing analgesia to sows at farrowing or to piglets at castration. Further analysis or further studies might show benefits to using analgesia where a small sow is delivering large piglets.

This work to date suggests that the routine use of ketoprofen to piglets at castration or to sows at parturition did not result in improved performance and was therefore not cost-beneficial. In general, the decision to use analgesia will most likely be based on ethical concerns and not on financial concerns.

January 2011