Growth and physiological response of juvenile common carp (Cyprinus carpio) to increased levels of dietary niacin

ABSTRACT

This study investigated the effect of different levels of dietary niacin on growth performance, feed utilization, digestive enzyme activity, and biochemical body composition of juvenile of common carp (Cyprinus carpio). A formulated basal diet with 28 mg native niacin kg⁻¹ was fortified with nicotinic acid to provide 50, 70, 90, or 110 mg kg⁻¹diet. Fish with initial average weight of 25 ± 0.28 g were fed to visual satiation three times per day in triplicate for 8 weeks. The results showed that 90 mg niacin significantly improved (P < 0.05) growth performance and feed utilization of fish compared to the control group. The increase in dietary niacin level resulted in an increasing trend of whole-body protein and lipid content (P < 0.05). Moreover, Lipase, total protease, and alkaline phosphatase activities were significantly higher (P < 0.05) in fish fed 90 mg niacin kg⁻¹ diet than that in the control group. Using polynomial regression, the optimum dietary niacin level in C. carpio juveniles was estimated as 98 mg kg⁻¹ diet when percentage of body weight gain was plotted against dietary niacin levels.

KEYWORDS:

• Vitamin
• growth
• enzyme
• feed
• common carp

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Khorramshahr University of Marine Science and Technology.