Nutrition for the sustainable production of tambaqui: tolerance to carbohydrates, protein-sparing effects and, use of alternative foods

Abstract

Nutrition is one of the main challenge of fish production because feed represents to 70% of total cost. Considering that the price of the feed rises as the protein content increases, the use of carbohydrates in the diet can result in a protein-sparing effect. The frugivorous eating habit of tambaqui (Colossoma macropomum) suggests that this species has physiological mechanisms for the use of foods rich in carbohydrates, but which have been little studied. Added to this, in the production of tambaqui in the Amazon region, the rations depend on raw materials from other states, with high costs, while Amazonas has a large generation of residues from the fruit pulp agribusiness that are potential alternative ingredients for fish feed. In this scenario, this proposal will allow the elaboration of economically more interesting diets that promote the healthy development of fish, both nationally, with the use of conventional ingredients, and regionally, with the exploitation of by-products of agro-industries in the Amazon region. In this way, we will be contributing to the tambaqui productive chain and with benefits to the other regional agro-industrial chains. At the same time, the proposal will bring significant contributions to the understanding of carbohydrate metabolism in fish, since most of the studies carried out by the international scientific community focus on carnivorous and / or temperate fish. The objective of this proposal is to evaluate the metabolic ability of tambaqui in using ingredients rich in carbohydrates and diets based on the protein sparing effect with conventional and regional ingredients, enabling the development of a sustainable technological package for the production of this species. For this, seven experimental tests will be carried out: 1- Tolerance to different sources of carbohydrates in tambaqui: glycemic curve and intermediate metabolism; 2- Study of glucose and fructose metabolic routes in tambaqui juveniles through metabolomics; 3- Nutritional value of conventional and alternative foods for tambaqui; 4- Study of biochemical and histological variables, content in the digestive tract and intestinal microbiota of wild tambaquis; 5- Use of an alternative ingredient in the feeding of tambaqui in the initial phase; 6- Performance and metabolism of juvenile tambaqui fed diets with different digestible protein:carbohydrates ratios and 7- Growth performance, fillet quality and cost of production with conventional and alternative ingredients for tambaquis destined for fattening. The performance of these experiments will contribute to the development of the technological package for the tambaqui production chain and the strengthening of a collaborative research network between the states of Amazonas and São Paulo, with the consequent formation of qualified human resources and with scientific maturity. (AU)