Supplementation of Yeast Extract to Practical Diet Improves the Growth, Anti-Oxidative Capacity and Intestinal Morphology of Shrimp Litopenaeus vannamei

Two control diets based on the commercial formula were designed to contain high (27%, D1) and low (22%, D2) levels of fish meal, respectively. Into D2, 500, 1000 and 1500 mg kg−1 of yeast extract were added, respectively, yielding three experimental diets (YE1 through YE3). Shrimp (initial body weight 0.30 g ± 0.02 g) were fed with the experimental diets, five tanks each diet and 30 shrimp individuals each tank, for 8 weeks, and then challenged...