Effects of fermented soybean meal with methionine and lysine supplementation on hemato-biochemical parameters, digestive enzyme activities and health status in Beluga, Huso huso

This study investigated the replacement of fermented soybean meal (FSBM) and supplemental methionine and lysine (ML) to assess hemato-biochemical parameters, digestive enzymes and health status of Beluga, Huso huso. Two basal diets contained fish meal + ML (490 g/kg; FM and FM+ML). Then, 40 %, 60 % and 80 % of FSBM and FSBM+ML were replaced (44.4% protein and 14.9% lipid; FM, FSBM40, FSBM60, FSBM80, FM+ML, FSBM40+ML, FSBM60+ML, FSBM80+ML); 240 Beluga (394.6+4.3 g) were fed for 56 days. Results showed the lowest blood performance (BP) in 80%; ML significantly lowered BP (P<0.05) except for 0 %. Total protein (TP) and albumin (ALB) decreased with higher substitution of FSBM and FSBM+ML (P<0.05). Triglyceride (TG), cholesterol (CHOL) and low-density lipoprotein cholesterol (LDL-C) significantly declined in Beluga fed FSBM and FSBM+ML (P<0.05). Complements were significantly lower in FM and FM+ML. 40% and 60 % showed higher superoxide dismutase (SOD) (P<0.05). Results indicated higher high-density lipoprotein cholesterol (HDL-C) in FSBM40, lower catalase (CAT) in FM and higher alanine aminotransferase (ALT) in FSBM80+ML (P<0.05). Also, ML reduced only TG and LDL-C (P<0.05). 40% and 60% showed higher protease and lipase, respectively; 80 % significantly reduced amylase. Moreover, ML improved digestive enzymes (P<0.05). Fermented SBM and ML significantly enhanced histological lesions; The villus height and intestinal muscle thickness decreased in 60 % and 80%, and goblet cells in 80 %. ML lowered intestinal muscle thickness (P<0.05). Generally, ML only improved TG, LDL-C and digestive enzymes. In most parameters, fermented SBM was up to 60 % more efficient, but cautiously up to 40 % for histological alterations.