This research aimed to determine the upper limit level of crystalline amino acid (CAAs) inclusion in tambaqui nutrition. Additionally, we investigated the possibility of total replacement of fish meal (FM) by soy protein concentrate (SPC). An FM‐based control diet was formulated to meet the known nutrient requirements of tambaqui, and three additional diets were prepared by replacing FM protein with 250, 500, and 750 g/kg nitrogen of CAA mixture. The fifth diet was formulated to completely replace the FM by SPC. A growth and a digestibility trial were performed in a completely randomized design with five treatments and three and four replicates, respectively. The optimum replacement level of FM protein by CAA was 280 g/kg based on daily weight gain (DWG). The apparent digestibility coefficients of the nutrients were higher in fish fed the SPC diet than the fish fed the FM diet. The whole‐body lipid and adiposity significantly declined with the increase of CAA in tambaqui diets. Protein and amino acid retention of tambaqui linearly declined with the increase of CAA. Blood chemistry metabolites were not affected by CAA inclusion. We concluded that the SPC could replace FM in tambaqui diets without affecting growth and nutrient digestibility. CAAs could replace FM intact protein up to 250 g/kg (or 97 g/kg inclusion level) without showing any adverse effect on growth and metabolism of tambaqui.

中文翻译：

---

用结晶氨基酸和大豆浓缩蛋白代替鱼粉蛋白对坦巴基巨像少年的生长，饲料利用和代谢的影响

这项研究旨在确定tambaqui营养中所含结晶氨基酸（CAA）的上限水平。此外，我们调查了用大豆浓缩蛋白（SPC）完全替代鱼粉（FM）的可能性。配制了基于FM的对照日粮以满足坦巴奎已知的营养需求，并通过以250、500和750 g / kg的CAA混合物氮替代FM蛋白来制备三种其他日粮。制定了第五种饮食以完全替代SPC的FM。生长和消化率试验以完全随机的设计进行，分别进行了五种处理，分别进行了三和四次重复试验。基于每日体重增加（DWG），CAA对FM蛋白的最佳替代水平为280 g / kg。喂食SPC饲料的鱼的营养成分的表观消化率高于喂FM饲料的鱼。随着坦巴基饮食中CAA的增加，全身脂质和脂肪含量显着下降。随着CAA的增加，坦巴基的蛋白质和氨基酸保留率线性下降。血液化学代谢物不受CAA的影响。我们得出的结论是，SPC可以代替tambaqui日粮中的FM，而不会影响生长和营养物质的消化率。CAA可以替代高达250 g / kg（或97 g / kg包含水平）的FM完整蛋白，而不会对tambaqui的生长和代谢产生任何不利影响。随着CAA的增加，坦巴基的蛋白质和氨基酸保留率线性下降。血液化学代谢物不受CAA的影响。我们得出的结论是，SPC可以代替tambaqui日粮中的FM，而不会影响生长和营养物质的消化率。CAA可以替代高达250 g / kg（或97 g / kg包含量）的FM完整蛋白，而不会对tambaqui的生长和代谢产生任何不利影响。随着CAA的增加，坦巴基的蛋白质和氨基酸保留率线性下降。血液化学代谢物不受CAA的影响。我们得出的结论是，SPC可以代替tambaqui日粮中的FM，而不会影响生长和营养物质的消化率。CAA可以替代高达250 g / kg（或97 g / kg包含量）的FM完整蛋白，而不会对tambaqui的生长和代谢产生任何不利影响。