title: Protein and energy relationships in the diet of the American alligator (Alligator mississippiensis).
abstract: First-year alligators (Alligator mississippiensis) averaging 377-857 g body weight were fed diets containing various levels of protein, fat and carbohydrate. In experiment 1, nine diets arranged in a centrally rotatable composite design contained 0-36% extruded corn and 4-20% total fat. Response surface analysis predicted maximum responses in performance criteria at 6.3-18.8% corn and 15.8-27.4% fat. Corn inclusion at up to 27-36% of diet resulted in equal or improved performance compared to carbohydrate-free diets of equal fat content. Energy digestibility averaged 84.3%. Protein digestibility averaged 86.7%. Maximum responses in performance criteria were predicted at 42.5-48.7% digestible protein and 4367-4421 kcal/kg digestible energy. In two additional experiments, alligators were either fasted or fed for various numbers of days/week. Carbohydrate-supplementation of high protein diets led to equal or significantly improved performances. Performance was maximized by feeding the alligators 5-6 d/w. Regression of body weight changes against energy and protein intake yielded estimates of daily maintenance requirements of 5.7-8.4 kcal and 0.49-0.89 g protein/kg live body weight. Dietary fat and carbohydrate in the forms and amounts fed to young alligators were well-utilized. Optimal digestible energy:crude protein ratios (8.2-10.9:1 kcal/g protein) were similar to those of other aquatic ectotherms of equal size.
authors.affiliation: Department of Poultry Science, University of Georgia, Athens 30602.
authors.forename: M A
authors.initials: MA
authors.lastname: Staton
authors.forename: H M
authors.initials: HM
authors.lastname: Edwards
authors.forename: I L
authors.initials: IL
authors.lastname: Brisbin
authors.forename: T
authors.initials: T
authors.lastname: Joanen
authors.forename: L
authors.initials: L
authors.lastname: McNease
mesh_terms: D000489:Alligators and Crocodiles / Q000378:metabolism*; D000821:Animal Feed; D000818:Animals; D001835:Body Weight; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism*; D004044:Dietary Proteins / Q000378:metabolism*; D004063:Digestion; D004435:Eating; D002149:Energy Intake; D004734:Energy Metabolism; D012044:Regression Analysis; D012104:Reptiles / Q000378:metabolism*; D003313:Zea mays
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins