Use of a mixture of barley-based fermented grains and wheat gluten as an alternative protein source in practical diets for Litopenaeus vannamei (Boone)

摘要

A combination of barley-based fermented grains (BFG) and wheat gluten (WG) meal (1:1 on a crude protein basis) was evaluated as an alternative protein-rich ingredient (BFG-WG) in diets for juvenile Litopenaeus vannamei. Four isocaloric diets were formulated to contain 44% protein in which protein from BFG-WG replaced 0% (A), 33% (B), 66% (C) and 100% (D) of the protein from marine animal protein (MAP: 69% shrimp head meal, 21% fish meal and 10% squid meal) in the diets. These diets were delivered twice a day for 6 weeks to shrimp (initial weight+/-standard error, 2.14+/-0.02 g). Shrimp fed diets A (control) and B showed similar weight gain at the end of the experiment. There were no significant differences among the survival rates of different dietary treatments (>96%). The amount of uneaten food was positively and significantly (r(2)=0.57, P<0.001) related to the level of inclusion of BFG-WG in the diets, suggesting that diet palatability was a major factor influencing shrimp growth. Diet D had the highest apparent digestibility for protein and dry matter. The inclusion of BFG-WG had a positive effect (r(2)=0.75, P<0.05) on carbohydrate digestibility. A significant stimulation of amylase activity and soluble protein and glycogen concentrations in the hepatopancreas also was related to the amount of BFG-WG in the diet. Feed conversion ratio and protein efficiency ratio were not significantly different among diets containing substitution levels of 0%, 33% and 66% of MAP, which could suggest that if the balance of amino acids and the palatability in the diet can be improved, replacement level of the MAP may be increased to 66% without reducing growth. [References: 43]