Effect of ultraviolet light and oral vitamin D3 on rachitic chicks fed diets containing either corn or rye.

Three experiments using day-old chicks were conducted in battery brooders to further study the rye-vitamin D antagonism. Birds were fed a vitamin D3-free diet containing corn or rye and submitted to diverse treatments for the first 10 days. At this time the chicks were either continued on the same diet or changed to other grain-type diets. The effect of ultraviolet light exposure on the chicks and of a single oral dose of vitamin D3 was studied, and body weight gain and bone ash were determined after a one-week experimental period. Rachitic chicks on a corn diet responded significantly better than rye-fed chicks to a single oral dose of vitamin D3, based on bone ash of fat-free, dry tibia. This rachitogenic effect of rye was completely overcome by exposing the chicks to ultraviolet light or by water extraction or acid-autoclaving this grain. The results also demonstrate that the interference by rye does not persist after this grain is removed from the diet.