Energetic metabolism of Piaractus mesopotamicus fed with starch sources in the diet

Abstract

ABSTRACT This work was to evaluate the effect of different starch sources on the performance and metabolism of Piaractus mesopotamicus. Three isonitrogenous (300 g kg−1 crude protein) and isolipidic (55 g kg−1 crude lipid) diets containing carbohydrate sources (corn, broken rice or sorghum) were formulated. Each experimental diet was fed to five groups (25 fish, 12.13 ± 0.09 g, per tank), three times a day during a period of 60 days. Cholesterol was lower in sorghum, and high density lipoproteins and hepatic glycogen were higher with the use of sorghum (P < .05). Low density lipoprotein was higher when feeding with corn. Plasma glucose was higher in treatments with broken rice and corn. Sorghum led to lower values of hepatosomatic, visceral and digestive somatic indexes. Enzymes activities (amylase, lipase, maltase) reduced their activities in fish fed with sorghum. Broken rice resulted in higher lipid content and lipid retention coefficient in whole fish. The data suggest that the growth of Piaractus mesopotamicus and digestibility are not affected by the chemical composition of starch from the carbohydrate sources tested, however, different metabolic behaviors occurred, either from the starch content in diet, the starch composition of each ingredient, or the pro-nutritional effect of sorghum.