Dietary thiamin requirement of fingerling major carp Catla catla (Hamilton)

Dietary thiamin requirement of fingerling Catla catla (3.5 +/- 0.15 g) was evaluated by feeding casein-gelatin-based iso-nitrogenous (350 g/kg crude protein) and iso-caloric (16.72 kJ/g GE) diets containing six graded levels of thiamin (0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg/kg dry diet) for 12 weeks. Significantly (p < 0.05) higher weight gain (AWG), best feed conversion ratio (FCR), protein retention efficiency (PRE), RNA/DNA ratio and haematological indices were recorded in fish fed diet containing 0.8 mg/kg thiamin. Dietary thiamin supplementation improved transketolase activity (TKA) and maximum value was recorded in fish fed 0.8 mg/kg thiamin beyond which stagnation in TKA activity was evident. Liver thiamin concentration was found to be maximum in fish fed diet containing 1.6 mg/kg thiamin. A significant (p < 0.05) consistent reduction in the hepatic thiobarbituric acid reactive substances (TBARS) activity was displayed with incremental concentration of thiamin up to 0.8 mg/kg, beyond which a reverse trend was evident. However, a significant (p < 0.05) improvement was noted in superoxide dismutase (SOD) and catalase (CAT) activity with the increasing level of dietary thiamin from 0 to 0.8 mg/kg. Broken-line regression analysis of AWG, FCR, PRE and TKA estimated the requirement in the range of 0.74-0.79 mg/kg dry diet.

Automated summary

Thiamin plays a significant role in the growth and health of fingerling Catla catla, with optimal levels improving feed conversion ratio, protein retention efficiency, liver function, and antioxidant capacity. The best effects were seen with a dietary thiamin concentration of 0.8 mg/kg.