Observations on the Influence of Dietary Protein Level and Amino Acid Balance on Pigmentation in the Feathers of Chicks ,

KLAIN et al. (1957) observed the development of a severe feather achromatosis in Barred Plymouth Rock cockerels fed a lysine-deficient diet. The diet used in these experiments supplied all the essential amino acids in apparently adequate quantities for normal growth with the exception of lysine. An evident question which arose from these results, therefore, was whether the low lysine intake in itself was the major factor involved in the deficiency of feather color, or, primarily, whether an unbalanced intake with respect to lysine and other amino acids was concerned. In order to investigate this problem a series of experiments was undertaken using a diet in which the protein level could be changed without altering the pattern of amino acids being offered. EXPERIMENTAL Barred Plymouth Rock cockerels were used in all experiments. They were housed in heated battery brooders and fed the experimental diets ad libitum from day-old to 4 weeks…