Concentrados de fibra alimentar como agente prebiótico em dietas de jundiá (Rhamdia quelen)

Abstract

This study aimed to evaluate the effect of inclusion of concentrated dietary fiber as prebiotic agent in diets on metabolic, immune responses, performance parameters, deposition of nutrients and production of digestive enzymes of juvenile silver catfish. Concentrates were prepared from dietary fiber citrus pulp, biomass of yeast brewery and grain included in linseed and mixed diets followed a diet containing the prebiotic commercial mananoligossacarids base Actigen® and control treatment without added prebiotic agent. For 50 days, 600 juvenile silver catfish with average initial weight of 3.54±0.53 g were kept in a water recirculation system with two biological filters, settling box, heating and 20 tanks with a capacity of 230 liters. Were randomly assigned to 30 fish per experimental unit, which were fed the experimental diets, three times a day (8:00, 13:00 and 17:00) to apparent satiation. At the end of the experiment the animals were subjected to biometrics were collected blood, liver, mucous, intestine and data length and weight, beyond a sample of fish. The experimental design was a randomized, with five treatments and four replications, the data were subjected to analysis of variance and means were compared by Tukey test (P<0.05). Cholesterol levels, total protein, globulin and mucoprotein were higher in animals fed yeast autolysate and linseed fiber in the diet. A higher amount of liver glycogen in fish fed with control diet and Actigen®, the liver protein content was higher (P<0.05) in a diet containing linseed fiber. Fish fed diets containing yeast autolysate and linseed fiber were superior (P<0.05) to the other treatments tested, as well as higher crude protein values and deposited body fat. Animals fed diets containing citrus pulp showed lower performance and nutrient deposition. The yield of body, digestive indices and production of digestive enzymes were not affected by the tested treatments. The yeast autolysate and linseed fibers provide a prebiotic effect when added to diets for juvenile silver catfish, since they benefit the immune system and provide improved performance and deposition of nutrients by the animal.