Maintenance nutrition in the pigeon. Vitamin B(3) concentrates.
VITAMIN B3 may be defined as a factor required for full weight restoration in the pigeon on a diet which, in addition to vitamins B1 and B5, includes an adequate supply of basal dietary constituents such as salts and protein. We have previously shown [Carter and O'Brien, 1935] that one of the factors involved in the failure of pigeons on a rice diet to recover normal weight is a partial deficiency of protein. Further, the weight recovery of birds on a diet adequate as regards vitamins B1 and B5 and protein is influenced by the severity of the depletion to which they are subjected on rice. It was observed that, whereas birds subjected to moderate depletion of stored vitamins recovered weight completely on receiving supplements of vitamins B1 and B5 and protein, with more drastic depletion many birds failed to regain their maximum weight on this diet. This may explain the differences between the results of Morris [1933] and those of Waterman and Ammerman [1935]. The former was led to question the existence of vitamin B3 on the ground that normal weight could be attained on a diet of autoclaved wheat and 6-16 times the curative dose of vitamin B1. The latter workers found that, on the same basal diet, pigeons receiving up to 160 y of crystalline vitamin B1 daily attained only 80-90% of their normal weight and concluded that a further factor was required for full weight recovery. In those birds which fail to regain their maximum weight on a diet with adequate protein we have found that full weight restoration was made on administration of an extract of liver which we consider to supply vitamin B3. The present paper gives further evidence of the character of this supplement from liver.