GROWTH RESPONSES OF CHICKS AND RATS FED DIETS CONTAINING FOUR CULTIVARS OF RAW OR AUTOCLAVED FABA BEANS

Abstract

Experiments were conducted with 480 male Leghorn chicks and 60 male Wistar strain rats over 21- and 35-day periods, respectively, to study the influence of heat treatment (autoclaved for 0, 15 or 30 min at 120 C) on the growth depressing factor(s) in four faba bean (Vicia faba L. var minor) cultivars (Klein-Thuringer, Diana, Hertz-Freya and Ackerperle). All diets, which were supplemented with methionine, contained 90% faba beans. Autoclaved (average of the two autoclaving times) as compared to raw faba beans in diets of chicks and rats resulted in significant (P < 0.05) improvements in the respective weight gains (9 and 6%) and feed:gain ratios (14 and 6%). Heat treatment of the faba beans also reduced (P < 0.01) feed intake (6%) and pancreas (16%) and liver (4%) sizes in chicks. The 30-min compared to the 15-min autoclaving time tended to give slightly greater improvements in growth responses. The response in chicks fed the autoclaved diets was more dramatic than that in rats, suggesting a difference between chicks and rats in their sensitivity to the thermo-labile facor(s) in raw faba bean. Hemagglutinin activity levels were markedly reduced, and trypsin inhibitor levels were reduced by approximately 50% in faba beans that had been autoclaved for 15 or 30 min. Weight gains in both chicks and rats as well as feed:gain ratio in chicks were positively associated (P < 0.05) with protein level in the diets. Pancreas size, however, did not differ (P > 0.05) among chicks fed the various faba bean cultivars. Trypsin inhibitor and hemagglutinin activity levels in the various cultivars were similar. These results suggest that the levels of growth depressing factors in the four cultivars are not markedly different.