Digestibility of different thermal processed grain of legumes, Rynchosia minima and Cajanus cajan, in white shrimp (Litopenaeus vannamei)

Since nutrition demands a high percentage of production costs in shrimp culture, the development of dietary strategies such as the inclusion of vegetable protein sources, is a very important tool. Thus, digestibility of alternative feedstuffs for evaluating its dietary potential as shrimp feed represents the first action. The objective of study was to determine digestibility coefficients for protein, energy, dry matter and amino acids of least snout bean and pigeon pea meals in Pacific white shrimp juveniles. Thirteen isonitrogenous diets (34.8 to 35% protein) were formulated and elaborated. One containing only fish meal as a source of protein and the other replacing 10 and 18% of fish meal with the leguminous seed meals Rynchosia minima and Cajanus cajan, previously subjected to a thermal process for 0, 45 and 90 min. The shrimp were fed to satiation four times daily for 25 day. The apparent digestibility coefficients were determined using 0.5% Cr2O3. Feces were collected from three replicate groups of shrimp. The results showed that shrimp fed with 10 and 18% Cajanus cajan and Rynchosia minima replaced and subjected to a thermal process of 45 min presented higher weight increase (p<0.05) and specific growth rate compared with control diet group. L. uannamei had relatively high apparent digestibility coefficients of crude protein (93.68 and 92.29%) and crude lipid (96.87 and 97.55%) for CC10-45 and RM18-45 diets, respectively. Results suggest that diets with both R. minima and C. cajan seed meals thermally processed, can partially replace animal protein in shrimp diets at inclusion levels of 10 and 18%, respectively.