STUPEFYING AND LETHAL EFFECTS OF ALPHA-CHLORALOSE IN CHICKENS

The effect of concentration of alpha-chloralose in a feed on mortality was examined using the chicken as an experimental model. When feed co ntaining alpha-chloralose at up to 15% was offered to chickens the rel ationship between the concentration of the alpha-chloralose in the fee d and its voluntary intake was non-linear. The intake of alpha-chloral ose increased when it was included at up to 10% of the weight of the f eed and declined as the concentration exceeded 10%. Mortality increase d from 9 to 53% when the concentration increased from 2 to 15% of the feed, and beyond a concentration of 15% mortality declined. When the o bjective is to maximise mortality as part of a pest control programme, it is suggested that an alpha-chloralose concentration of between 10 and 15% would be appropriate. When the objective is to use alpha-chlor alose for capturing live birds it is important to use much lower conce ntrations. Even at a 2% concentration some birds died. In one trial us ing a 10% concentration in 24-hour fasted birds, up to 94% of the bird s were killed within 8 hours. The anticonvulsant effect of alpha-chlor alose in response to neck dislocation of sedated birds was found to be greatest when a 10 to 15% concentration was used.