EFFECTS OF LOW AND HIGH DIETARY LEVELS OF BETA-AMINOPROPIONITRILE (BAPN) ON THE PERFORMANCE OF LAYING CHICKENS

In two experiments, commercial laying pullets and hens were fed diets containing either low or high concentrations of beta‐aminopropionitrile (BAPN), the toxin present in some legume seeds in the genus Lathyrus. BA PN was fed as mono‐beta‐aminopropionitrile fumarate. The main effects of feeding BAPN to laying birds appear to be on shell formation, egg weight and egg production. Heavier eggs, abnormal in shape and shell texture, were frequently obtained when BAPN was included in the diet. Effects on both egg weight and egg malformation were observed with or without a reduction in egg production. The toxic level of BA PN fumarate in the diet of laying birds appears to lie between 0.1 and 0.2 g kg−1. Considering BAPN content in seeds of different Lathyrus species and the level of active constituent of BAPN fumarate which had adverse effects, it was found that Lathyrus seeds which contain BAPN as a toxic constituent have margins of safety and could be utilised to constitute a proportion of the layer diets without any deleterious effects. Copyright © 1990 John Wiley & Sons, Ltd