EFFECT OF DIETARY PROPIONIC-ACID ON REQUIREMENT OF CHICKS FOR VITAMIN-B12

1. Test diets were given to chicks from 1 to 28 d of age. The basal diet contained soyabean meal as the sole source of protein and contained no vitamin B12. 2. The basal diet supported poorer growth and feed conversion efficiency than did the same diet supplemented with 0.01, 0.03 or 0.3 mg cyanocobalamin/kg. 3. Each of the four diets was also offered with a supplement of 20 g propionic acid/kg. This caused a significant growth depression at all but the highest level of cyanocobalamin addition. 4. Methylmalonic acid was detected in the excreta of chicks that received the supplements of 0 and 0.01 mg cyanocobalamin/kg diet, and in those of chicks receiving 0.03 mg only for the chicks that were also receiving propionic acid. 5. The results suggest that giving the odd-carbon, propionic acid to chicks may increase their requirement for vitamin B12. © 1974, The Nutrition Society. All rights reserved.