Effect of Dietary Energy Source on Racing Performance in the Pigeon

IT IS now a well accepted fact that the breast muscles of flying birds utilize fat as the major fuel for energy during sustained flight. It has been estimated by George and Jyoti (1955) that at least 77% of the energy expended in a pigeon subjected to sustained muscular activity is due to the oxidation of fat. Similarly, Visscher (1938) has shown that the heart obtained nearly all its energy from fat. George and Vallyathan (1964) observed that stimulation for 1 hr. of the breast muscle of pigeons brought about a decrease in the plasma free fatty acids level with a subsequent increase in the muscle. Carlson (1967) also has reported changes in the FFA level of the blood during sus-stained exercise in humans. This information led us to ask which dietary nutrient, fat or carbohydrate, could serve as a more efficient source of energy to racing homers under actual…