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

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.

KEYWORDS:

• Amylopectin
• amylose
• broken rice
• carbohydrate
• corn

Take home message

Research once again offers us new knowledge for the development of science. The take-home message, from the results of this study, is that cost reduction in fish feeding should not be done randomly and irresponsibly. We might even think that fish, like other animals, can eat whatever they can, indiscriminately, and shouldn’t follow a specific diet, as humans do.

This study demonstrates the seriousness of an experiment about changing the diet of fish, so that this new habit does not interfere with their usual performance, their metabolism, protein glycemic index and growth rate are not affected. In addition to reducing costs, the research also reveals organic improvements, such as a reduction in body lipids and a reduction in visceral fat.

Given the above, we are at your disposal to include, if you judge it convenient or necessary, all or part of this clarification in the conclusion or in any other topic that you deem pertinent.

Aknowledgements

We would like to thank the Federal University of Santa Maria for the opportunity of the experiment execution, funding and all laboratory analyzes; and CAPES-MEC Brazil for the scholarship to the first author.

Disclosure statement

No potential conflict of interest was reported by the author(s).