Comparison of Nutritional Effects Induced in Chicks, Rats and Mice by Raw Soya-bean Meal.

The growth-depressing effect of a raw soya-bean diet (RSD) on chicks and rats is well established (Liener, 1962). Pancreatic hypertrophy was observed in both species when given RSD (Chernick, Lepkovsky & Chaikoff, 1948; Booth, Robbins, Ribelin & DeEds, 1960; Alumot & Nitsan, 1961). It was found that chicks given RSD showed markedly depressed proteolytic activity in the small intestine during the first hours after food ingestion (Alumot & Nitsan, 1961). On the other hand, observations reported by Lyman & Lepkovsky (1957) indicate an increased proteolytic activity in the small intestine of rats given RSD. In earlier work in our laboratory evidence was obtained that the chick's caecums play an important part in the utilization of raw soya-bean protein (Nitsan & Alumot, 1963). It was the purpose of this work to compare the nutritional effects of RSD on birds and mammals, and to investigate the proteolytic activity in the small intestine and caecum of both under the same conditions. The growth-depressing action of RSD when given to rats can be overcome to a great extent by addition of antibiotics (Gebhardt & Columbus, 1957; Borchers, 1958, 1961 ; Braham, Bird & Baumann, 1959). The influence of antibiotics on chicks given RSD was therefore examined as well. The experiments were designed to study whether the action of antibiotics on growth of rats and chicks is connected with enhanced proteolysis in the small intestine or caecum, or both, or if there are any other reasons for the positive effect of antibiotics added to RSD. The comparison of the effect of RSD on the two types of animal may contribute to a better understanding of the mechanism of the growth retardation induced by RSD.