Historically the importance of proper quantification of the fiber of food as well as effects nutritionals, digestives and metabolics, has been delegated to second plan in fish nutrition. Most approaches emphasize the negative aspects of its presence in the diet (Wilson, 1995; Tripathy and Mishra, 2007) without considering that, when in adequate amounts, its effects can be as important as those of the commercial prebiotics currently applied as promoters of the development of beneficial microbiota in the digestive tract, which reflect positively on the performance and body composition of animals
The results of Yarahmadi et al. (2014) demonstrated that using fiber sources for fish is promising and should be explored further in order to optimize animal performance and immune response. Fiber sources are typically plentiful and discarded by the Brazilian agribusiness, taking massive densities of nutrients of significant nutritional application and causing considerable environmental impacts due to improper waste disposal. However, these fiber sources can be extensively exploited as eco-friendly growth promoters in fish nutrition, contributing to the production of fish with greater food security and, at the same time, acting as a mitigating agent. Brazilian fish farming is developing rapidly, turning to breeding native species such as catfish (Rhamdia quelen), which are typically more susceptible to the stresses resulting from high density stock breeding compared to other species consolidated in the international market, such as carp (Cyprinus carpio) and tilapia (Oreochromis niloticus). This fact requires nutritional strategies that assist in maintaining the health of animals and promoting growth, even under adverse conditions, and the use of prebiotics in feed agents may be promising. Inthis context,the additionofdietaryfiber inthediet shouldbe studiedinorder to elucidate its effects onfishperformance, since there are abundant sources of fiber being discarded by Brazilian agricultural industries. The aim of this study was to evaluate the effect of the nutritional dietary fiber derived from agroindustrial disposal on productive performance, nutrient deposition and activity of digestive enzymes the juvenile silver catfish