Response of growing turkeys to dietary energy levels.

Two consecutive trials were conducted with male Large White turkeys grown from day-old to 20 weeks of age on diets formulated to contain 0, 2, 4, 6, and 8% fat with constant amino acid energy ratios. The addition of 2 and 4% fat significantly improved body weight gain; higher levels gave no further improvement. Feed conversion efficiency was improved by the addition of fat to the diet, but caloric efficiency remained relatively constant over the range of energy levels, indicating that there was not "extra-caloric" effect of fat observed in this study. Possible contributions of methods of feed formulation toward the possibility of the occurrence of this phenomenon are discussed.