Growth Activity of 5-Hydroxybenzimidazole Analogue of Vitamin B12 in Chick

Three successive experiments were conducted to evaluate the activity of a 5-hydroxybenzimidazole analogue of vitamin B12 (B12-FIII) in comparison with cyanocobalamin by chick growth assay. In all experiments, Single Comb White Leghorn chicks were used, bred from hens given all vegetable diet for 3-4 months. Chicks were divided into 4-6 lots at the end of the second week after hatching, and fed for three weeks with all vegetable, high protein diet supplemented with graded levels of cyanocobalamin or 3μg of B12-FIII per 100g of basal diet. From the comparison of body weight gain during the experimental period, it may be concluded that the activity of B12-FIII for chick growth is about 10% of that of cyanocobalamin.