Digestibilidade aparente de derivados de soja (Glycine max), parâmetros hematológicos e desempenho de juvenis de Tilápia do Nilo (Oreochromis niloticus)

Abstract

This work was carried out to determine the apparent digestibility of soybean products: soybean meal white (FSB), soybean extruded and pressed (FSP), conventional soybean meal (FSC) and protein isolate soybean (IPS) and the basal diet, and assess whether these derivatives cause injury to health and performance of Nile tilapia (Oreochromis niloticus). For the first study, we used approximately 385 juvenile tilapia with mean weight 26 ± 6.31 g, distributed in five conical tanks with a capacity of 90L. The experimental design was a Latin square. The animals were submitted to the method of fecal collection by sedimentation. During the experimental period were measured average values of temperature, dissolved oxygen, pH and electrical conductivity were measured. The IPS had the best CDaEB index of 84.33%. For CDaPB, there were no significant differences between treatments, with values above 90%. The largest value of digestible energy (ED) was 4139Kcal ED / kg for the IPS. To digestible protein (PD) IPS presented the value of 79.11%, followed by the FSB, and FSC FSP. After the stool collection period, fish were fed for 45 days for evaluation of hematological and biochemical parameters of tilapia. For blood tests, were captured at random eight fish weighing on average 94.17 ± 8.60 g. Through blood tests, there was a significant difference between treatments for hematological parameters of hemoglobin and hematocrit to biochemical parameters showed higher triglyceride levels in the analysis of basal diet. The second study aimed to evaluate the performance of tilapia when exposed to soy-based diets (White, IPS, and Conventional Soybean extruded and pressed). We used 200 tilapia with initial weight of 3.6 g and total length averaging 5.2 cm, distributed in 20 experimental cages, housed in a greenhouse. The distribution of treatments used was a fully cazualizado design with four treatments and five replicates for 60 days. Were prepared five isonitrogenous and isocaloric diets containing 28% digestible protein and 3,300 kcal ED / kg. At the end of the experiment, fish were weighed and measured individually, where he obtained the calculations of weight gain, feed conversion, feed efficiency, survival rate and condition factor. At the end of the experiment, there were no statistical differences in the composition of fish among treatments and productive performance. It follows that all foods have excellent CDa evaluated with values above 90% protein digestibility. Derivatives of soy are foods high protein, with excellent rates of apparent availability of its nutrients. The soy-based diets do not cause harm to health of tilapia compared with the reference diet, and can be used as food in order to formulate least cost rations for flour in place of animal origin for this species, and that feeds the base of soy products do not cause damage to the performance of tilapia compared with the reference diet.