The effect of azaperone on the agonistic behaviour of boars: a pilot study

Previously unacquainted adult boars are often penned together and transported over long distances. This study examined the effect of azaperone, a drug used to reduce fighting in young pigs, on the behaviour of adult boars in close confinement.Five groups of six adult boars were used. Three groups were treated with 4% azaperone at 1.5 mg/kg, the other two groups served as controls. Behaviour was monitored for 24 hours. Azaperone reduced the intensity and ferocity of fighting during the peak activity of the drug but it did not eliminate aggressive behaviour. There was an increase in threat behaviour and the number (but not the intensity) of fights greater than one minute in the treated animals. This drug could be used when transporting boars in close confinement for short periods (less than four hours) if the boars are detusked.