A study on dietary vitamin B1 requirement of Litopenaeus vannamei.

An experiment was conducted to determine the requirement of dietary vitamin B1(thiamine,TN)for juvenile Litopenaeus vannamei.Semi-purified basal diets were formulated using vitamin-free casein,gelatin and fish meal as protein resources.Graded levels of TN were added to the basal diet which analytically contained 0.83,19.70,37.40,50.80,65.30,94.20,163.00 and 323.00 mg/kg diet,respectively.Each diet was fed into tanks of three replicates of shrimp(mean weight of(0.55±0.03)g)for 42 days.Results indicated that the specific growth rate(SGR)and feed efficiency of shrimp fed diets supplemented with thiamine were significantly higher than those of shrimp fed non-supplemented diet(0.83 mg/kg diet)(P0.05).Shrimp fed 19.70~50.80 mg/kg diets had a significantly higher survival rate(P0.05).There was no significant difference in body composition and hepatopancreatic amylase activity among the groups(P0.05).The activity of serum transketolase(TKA)was the highest in shrimp fed 50.8 mg/kg diet,significantly higher than that of shrimp fed the non-supplemented diet.SGR and TKA in serum were found to be suitable indicators,and analysis of broken-line regression indicated that the dietary vitamin B1 requirement of Litopenaeus vannamei was estimated to be 23.90 and 23.70 mg/kg diet,respectively.