The Effects of Dietary Thiamine Supplementation on Snubnose Pompano, Trachinotus blochii (Lacepède, 1801)

Abstract

Dietary thiamine supplementation was evaluated in juvenile snubnose pompano, Trachinotus blochii, with an initial mean body weight of 6.87 ± 0.18 g. Five dietary treatments were tested: an unsupplemented control and diets supplemented with 2, 4, 8, or 16 mg thiamine kg⁻¹ feed. Each treatment had three replicate cages, with 35 fish per cage, and the feeding trial lasted four weeks. Growth performance, survival, feed conversion ratio, condition factor, and hepatosomatic index were assessed. Specific growth rate ranged from 2.60 to 2.94% day⁻¹. Fish receiving 2–8 mg thiamine kg⁻¹ feed had significantly higher growth rates than the control (P < 0.05), whereas supplementation at 16 mg kg⁻¹ did not produce a significant growth advantage. Feed conversion ratios in the 2–8 mg kg⁻¹ treatments ranged from 1.85 to 1.91 and were significantly lower than that of the unsupplemented control. Survival ranged from 90.60 to 92.80% and did not differ significantly among thiamine-supplemented treatments. Condition factor and hepatosomatic index also showed no significant treatment effects. Under the conditions of this four-week trial, dietary thiamine supplementation at 2–8 mg kg⁻¹ feed improved growth and feed utilisation without significantly affecting survival, condition factor, or hepatosomatic index. The results therefore describe a short-term growth and feed-utilisation response within the 2–8 mg kg⁻¹ supplementation range in juvenile snubnose pompano.