Observations on the Requirements of Young Chicks for Dietary Fat

Abstract

In three experiments conducted with New Hampshire chicks, highly significant growth increases were obtained as early as two weeks by the addition of 3% of corn oil to the “fat-free” (0.05% fat) basal diet. An additional response was obtained by the supplementation of the basal diet with 15% of corn oil, a hydrogenated vegetable oil, or butterfat. Responses to the different fats were of equal magnitude. Supplementation of the “fat-free” diet with 0.33% of methyl linoleate also resulted in significantly increased growth. The growth response obtained from penicillin was significantly greater than that obtained with 3% of corn oil at two weeks of age, but was significantly less at 6 weeks. The 6-week body weights of the groups receiving the 3% corn oil or the penicillin treatment were significantly greater than those of the “fat-free” basal group. Fungicidin in the “fat-free” diet was without apparent effect. Liver vitamin A analyses showed clearly that the poorer growth of the “fat-free” groups was not due to a vitamin A deficiency, and further indicated that gelatincoated vitamin A was absorbed in large amounts from “fat-free” diets by the chick. Postmortem observations showed symptoms of aspergillosis. This infection was more severe in the “fat-free” groups.