Liver Damage and Growth in the Rabbit

Abstract

A diet of whole-milk powder (fortified with manganese, copper, iron, and iodine) is inadequate for the rabbit in at least two respects. Growth is subnormal and the livers are fatty and cirrhotic. Large amounts (50%) of dehydrated alfalfa meal are needed to prevent liver injury, while only small amounts (1%) are needed to stimulate the growth rate. Experiments involving 23 diets and 177 animals indicate that milk does not contain a toxic factor responsible for these results, and that the results are not due to the lack of roughage or of any of the known fat- and water-soluble vitamins or of the labile methyl groups. Preliminary attempts to extract the growth-promoting factor from alfalfa with water were unsuccessful. Purified diets when supplemented with a complete vitamin mixture offered no protection against liver damage, but when supplemented with yeast offered partial protection. In these diets crude casein produced better growth than purified casein, indicating the need of the rabbit for a third factor, possibly similar to the “animal-protein factor” of Cary et al. ('46) and Coombs ('47).