| Two series of experiments were conducted in the southern catfish , which is an important commercial species in the Three Gorges area , by a continuous-flow respirometer at 27.0±0.5 J In experiment â… , influence of feeding on oxygen consumption and ammonia excretion was studied to test relation between oxygen consumption and ammonia excretion during specific dynamic action (SDA) , using fresh Misgurus anguillicaudotus as diet . In experiment â…¡ , four diets with isonitrogenous (40% protein), isolipidic (10%) and graded levels of carbohydrate level (0% , 12% , 18% , 30%) were formulated to study the effect of dietary carbohydrate level on oxygen consumption and nitrogen excretion , and to test if dietary carbohydrate level could influence the level of protein metabolism during SDA. The results as follows :(1) After feeding , oxygen consumption rate and ammonia excretion rate; increased drastically, and reached their maximum levels in a short time , then decreased slowly to their resting levels in the two experiments . The peak , the time to peak , the magnitude and the SDA duration of the ammonia excretion rate were similar to those of the oxygen comsumption .(2) After the 4th day fasting , approximate 11.7% of energy for the fasting metabolism was provided by protein as fuel , but 79.4% for the SDA processes following feeding with the Misgurus anguillicaudotus as its food . It indicates that the energy for resting metabolism in short time fasting was mostly provided by body lipid... |
