Niacin Deficiency in Rabbits and Response to Tryptophane and to Niacin

Abstract

Growing rabbits fed a purified ration without the addition of niacin for 8 wks. developed anorexia, loss of wt., reduction of Hb and the cellular components of the blood. Continuing the ration for another 4 wks. resulted in more intense deficiency symptoms. At the end of the 12 weeks period, there was a reduction of niacin cone, in the livers and the hamstring muscles. After 8 wks. on the deficient ration, rabbits were treated by mixing 400 mg. of dl-tryptophane per rabbit or 10 mg. niacin/kg. body wt. daily into the diet for 4 wks. The rabbits responded with increased appetite, gain in wt., and gain in Hb, hematocrit and white blood cells in about equal proportions. When tryptophane and niacin were fed, the gains were greater. The niacin in the livers increased when tryptophane or niacin were fed. The niacin levels in the muscles were increased only when niacin was fed.