Vitamin A Deficiency in Chicks Fed Purified Rations Containing God Liver Oil. ∗

Abstract

Previous publications from this laboratory 1 , 2 , 3 have described a type of paralysis of nutritional origin in growing chicks characterized by ataxia, loss of equilibrium, staggering gait, and lack of growth. This condition has been ascribed to vitamin B₄ deficiency. More recently histopathological studies on such paralyzed chicks revealed certain lesions which were very similar to those occurring in uncomplicated vitamin A deficiency, in spite of the fact that these chicks were receiving rations which contained 2% of cod liver oil of medicinal grade. This oil contained at least 1500 vitamin A units (U.S.P.X.) per g. These findings led to an investigation of the adequacy of this level of oil as a source of vitamin A in purified rations kept at room temperature. The data are given in the table.

Ration 452S had the following composition: dextrin 70, reprecipitated casein 18, salts No. I 5, brewer's yeast 2, and water extracted lung 5. Ration 452 contained in addition 2% each of liver extract, autoclaved liver residue, and cod liver oil. Ration 459 contained in addition to the ingredients of 452S 2% of liver extract, 8% of defatted peanut residue, 2% of cod liver oil, and 5% of grit. These additions were made at the expense of the dextrin.

The results were very striking when either Oleum Percomorphum or a suspension of carotene in water was administered to chicks receiving these rations. There was complete prevention of the loss of equilibrium and staggering gait. For the most part the chicks were able to survive the experimental period, and there was a slight improvement in growth in some cases. However, the paralysis and incoördination of the leg muscles was accentuated so that the chicks walked with a characteristic high stepping gait and stood with hocks thrust forward and toes stiffened and extended as though there were a hypertonicity of the extensors. Tremors were observed in some cases. Thus it appears that loss of equilibrium is not a part of the vitamin B₄ syndrome, but is caused by a complicating deficiency of vitamin A, and that vitamin B₄ deficiency is characterized chiefly by incoördination of the leg muscles.