Effects of Anti-nutritive Constituents of Unprocessed Jack Bean (Canavalia ensiformis) (L) (DC) Seed Meal on Poultry Performance

Abstract

Jack bean (Canavalia ensiformis) is a good source of plant protein as well as a starch-storing seed and on the basis of the apparent nutrient content, it should be an extremely useful ingredient in animal feeds. The use of untreated Canavalia ensiformis seed as a feedstuff for poultry is restricted due to the presence of anti-nutritional factors, as is the case with the other tropical legumes. The anti-nutritional constituents of Canavalia ensiformis have been reported to include tryspin inhibitors and concanavalin A which are heat-labile and canavanine and canaline which are hydrosoluble. Other antinutrients are saponins, cyanogenic glycosides, and phenols. Canavalia ensiformis seeds can be used as an animal feed ingredient since they are a good source of starch and protein. However, in order to be used as animal feed ingredient, Canavalia ensiformis seeds would have to be thermally processed. Heat processing is universally accepted as an effective means of inactivating most, if not all of the heat-liable toxic constituents of legume grains. Research has showed that dietary inclusion of detoxified jack bean seed between 20-30% in feed ration is capable of supporting the growth of poultry birds without adverse effects on performance and physiological parameters of the animals. Several research works had been carried out on how to improve the quality of legumes. These researchers have reported many processing methods. Interestingly, on many occasions, in order to achieve complete inactivation or detoxification of these anti-nutritional factors a combination of two or more processing methods may be needed.