Studies with chicks on the growth depressing factor(s) in faba beans (Vicia faba L. var. minor).

The growth response of broiler chicks was improved when they were fed diet containing high levels (greater than 85%) of heat treated as compared to raw faba beans. Pelleting and microwave treatment of faba beans containing 10% moisture resulted in maximal improvements in chick growth rates and feed efficiency of only 6% and 8%, respectively. Steam autoclaving (121 degrees for 20 minutes), extrusion (130 degrees or 152 degrees), or microwave treatment of faba beans containing 18% added water resulted in maximal improvements of 16% in growth rates and 19% in feed: gain ratios. the above study, a time course study of the relationship between faba beans autoclaving time anc chick growth response, and studies with individual faba bean fractions (starch isolate and protein isolate) suggests that processing improves the utilization of faba bean mainly through its effects on components associated with the protein and possibly the hull portions of faba beans. The utilization of faba bean starch is not improved with processing. Although the nature of the growth depressing factor(s) has not been established, the results from this study indicated that the major component does not appear to be a tryspin inhibitor, hemagglutinin, some other heat labile protein, or vicine.