Unidentified factor activities in whole soybeans required for optimum growth of Coturnix quail

Effects on feed palatability of ingredients believed to contain unidentified growth factors for poultry

The influences of several feedstuffs on the free-choice feeding behavior of Japanese quail, Single Comb White Leghorn (SCWL) chicks, broiler-type chicks, and SCWL hens were investigated. Each type of animal showed significant feeding preferences for diets containing practical feedstuffs popularly associated with unidentified growth factor (UGF) activities. Among these, diets containing menhaden meal and corn distillers' dried solubles were preferred most frequently. Results indicated that a component of the UGF activities of practical feedstuffs may be an increase in feed palatability. Controlled feeding diets containing menhaden meal to Japanese quail demonstrated a typical UGF effect in addition to a palatability effect.

Effects on germ-free and conventional quail of substituting isolated soya protein for free amino acids in a purified diet

1. Germ-free and conventional Japanese quail reared on a diet in which the nitrogen was supplied solely in the form of free amino acids grew well, but growth was significantly better in both environments when some of the amino acids were replaced by an equivalent quantity of isolated soya protein. 2. Although the small intestine was shorter in the birds given the soya protein supplement, its weight per unit of length was greater; histological examination suggested that its circumference and wall thickness were both increased. 3. Results of a small experiment with conventional quail given the diets marked with 14C-polyethylene glycol indicated that the free amino acid diet passed through the gut more rapidly than the supplemented diet. 4. It was concluded that the growth-promoting effect of the isolated soya protein was unrelated to the activities of the gut microflora but might be due to changes in the digestive and absorptive capacities of the small intestine induced by the different physical nature of the supplemented diet.