Alternative protein sources in nutrition and metabolism of jundiá:in nature and demucilaged linseed meal

This study evaluated the growth response and metabolic effects of partial replacement of animal protein source with in natura (LM) or demucilaged (DLM) linseed meal in the diet of jundiá (Rhamdia quelen) juveniles. After demucilagen increased crude protein content and reduced soluble fiber of linseed meal. During seven weeks, 240 jundiá juveniles were reared in water recirculation system and fed to apparent satiation with the following diets: control diet (meat and bones meal and soybean protein concentrate as the main protein sources); 17% LM (17% crude protein of linseed meal replacing meat and bones meal); 17% DLM (17% crude protein of demucilaged linseed meal replacing meat and bones meal) or 35% DLM (35% crude protein of demucilaged linseed meal replacing meat and bones meal). At the end of the experiment, weight, total and standard length of the animals did not differ between treatments, but lower values of feed conversion were found in the control group. As for metabolic response, animals fed with 35% DLM diet showed higher level of glucose and cholesterol in plasma, but triglycerides, albumin, total protein and liver biochemistry (glycogen, glucose, lactate, protein, amino acids, ammonia) were not changed between treatments. The results demonstrated that in natura and demucilaged linseed meal can be used in the diet of jundiá without compromising metabolic parameters and final weight.