The Effect of Diet and Breed of Chicken on the Metabolic Efficiency of Nitrogen and Energy Utilization

INVESTIGATIONS demonstrating that there are specific breed differences in energy requirements and utilization attributed to genetic and physiological variation have been reviewed by Begin (1967). In this same report it was shown that, in a comparison of six breeds of chickens, the White Leghorn breed was significantly less efficient in its ability to utilize dietary protein and energy when the criterion of measurement was weight gain per unit of metabolizable energy and protein consumed. The two studies presented in this paper were undertaken to investigate further the relative ability of various breeds of chickens to utilize nitrogen and energy when measured as the tissue retention of these nutrients. Included in this investigation was a study of the effect of breed of chicken on the utilization of carbohydrates and fat as energy sources. Reports by Brambila and Hill (1966), Donaldson et al. (1957), Rand et al. (1958) and Renner (1964) have…