Caracterização de silagens produzidas a partir do resíduo de beneficiamento da indústria de pesca

Abstract

Due to the decrease and the high price of animal protein and lipid sources, such as fish meai studies in this area, especially in relation to aquatic organisms nutrition. Acid silage from fish residue is an alternativo to obtaining protein rich material used in the preparation of animal feed. The present study aimed to obtain and characterize the acid silage of gilged catfish residue Brachyplatystoma rousseauxii, piramutaba catfish Brachyplatystoma vaillantii and acoupa weakfish Cynoscion acoupa from the residues of processing industry. The silages were prepared with acetic acid as acidifying agent, potassium sorbate as fungiostatic agent and citric acid as antioxidant agent. The bromatological composition of the silages was determined for moisture, lipids, proteins and ashes. Temperatura and pH monitoring were performed throughout the process. Additionally, silage quality was evaluated through microbiological analyzes, nutritional quality through amino acid profile determination by chemical score (EQ) comparison with fish meai ingredients with 54 and 61% protein (FP54 and FP61), poultry viscera flour (AVF) and soybean meai (FS) and the essential amino acid index (IAAE). The pH and temperatura of the silages showed stability during the 30 days of ensiling. The highest percentage moisture content was found in gilged catfish silage (71.33%), followed by acoupa weakfish silage (69.40%). For ash, there were no statistical differences between silage results. Fipid contents were higher in piramutaba catfish (14.34%) and acoupa weakfish (13.53%) silages. The highest protein content was found in gilged catfish silage (16.31%), followed by piramutaba catfish silage (15.13%) and acoupa weakfish (14.53%). Regarding microbiological analysis, Salmonella, mold and yeast, thermotolerant coliforms at 35 0C positive coagulase staph were not found. The amounts of amino acids lysine and glutamic acid were in higher concentrations than the other essential and nonessential acids, respectively. For gilged catfish silage, piramutaba catfish and acoupa weakfish lysine values were 9.78%; 8.68% and 9.97%, and for glutamic acid were 15.88%; 13.88%; 15.07%, respectively. By EQ, the amino acid tryptophan was the only one in deficiency and the limiting factor in the comparison of acoupa weakfish silage with FS. In the other comparisons, the silages presented higher values of the essential amino acids in comparison with the selected ingredients. The highest IAAE values were obtained with gilged catfish silage, proving to be a better quality protein source. Ali studied silages were able to meet the essential amino acid requirements for juveniles of the tilapia Oreochromis niloticus and rainbow trout Oncorhynchus mykiss as the sole protein source. The results of the study showed that despite the differences in the silage composition of the gilged catfish, piramutaba catfish and acoupa weakfish residues from the fishing industry, ali can be considered nutritionally viable alternative ingredients as a protein source in diets formulated to replace the main protein ingredients used in the formulation of diets for aquaculture. However, mention should be made of the importance of silage testing in practical diets for breeding species.