Effects of Butafosfan on salivary cortisol and behavioral response to social stress in piglets.

We assessed the efficacy of Butafosfan, a component of Catosal, in the metaphylactic treatment of stress in pigs. Four 6-week-old female littermates were taken from 12 litters. They were confronted with a pig from a different litter for 2 h. There were 24 pairs, each consisting of confronting two unfamiliar pigs in a new pen. This housing of unfamiliar pigs provides a good, but simple, model of the psychosocial stress that pigs experience when housed in large groups on pig farms. Immediately before being housed with an unfamiliar pig, 12 pairs of pigs were injected subcutaneously with Catosal at a dose equivalent to 20 mg Butafosfan per kg body weight; the other 12 pairs received the control solution containing all ingredients of Catosal except Butafosfan. The frequency and duration of aggressive behavior and the salivary cortisol response were measured during the first 2 h of the encounter. No adverse effects associated with Catosal were observed. Subcutaneous injection of Catosal reduced the stress-induced salivary cortisol response and the frequency of aggressive behavior evoked by the social stress of housing two unfamiliar pigs together.