Specific dynamic action and diet in largemouth bass, Micropterus salmoides (Lacépède)

Apparent specific dynamic action (SDA) in largemouth bass (5-28 g) was equated to oxygen uptake subsequent to the ingestion of a meal. The effects of six diets on apparent SDA were investigated, one balanced or standard diet and five consisting of different proportions of protein and carbohydrate. Apparent SDA was positively related to gross energy ingested and to the level of dietary protein. For a given energy intake, apparent SDA was highest and lowest for diets of 100% protein and 100% carbohydrate, respectively. Evidence of a protein-sparing effect was found when the carbohydrate component represented 25% of the diet and the energy intake was less than 0.8 kcal. Apparent SDA was divided into mechanical SDA, the energy cost for the physical processing of food, and biochemical SDA, the energy cost of anabolic and catabolic processes associated with a meal. Biochemical SDA increased with energy ingested irrespective of diet and was higher by approximately an order of magnitude when bass were fed 1.5 kcal of a 100% protein diet than when fish received an isocaloric meal of 100% carbohydrate. Rate of oxygen uptake following feeding remained above the prefeeding level for 12-72 hours depending on diet and energy ingested.