The Relationship of Dietary Energy Level and Density to the Growth Response of Chicks to Fats

FATS from several sources have been reported to stimulate growth rate when added to diets for chicks. Included in this group are the oils derived from corn, peanuts, cottonseed and soybeans, egg oil, and lard. The reports on this subject have been reviewed by Rand et al. (1958), Hill et al. (1958), Dam et al. (1959), Denton and Menge (1959), Carew et al. (1959) and Menge and Denton (1961). This effect of certain fats on growth rate may reflect the presence of a required nutrient or may be related to the higher caloric density of diets containing added fat. Results which would support the latter possibility have been presented for fats of both animal and vegetable origin. Work by Baldini and Rosenberg (1957) showed that growth responses to beef tallow did not occur when energy levels of diets containing added fat were maintained isocaloric to that of the low-fat basal…