Dietary protein requirement of Indian Butter catfish, Ompok bimaculatus (Bloch) fingerlings

ABSTRACT

A 60-d feeding trial was conducted to assess the dietary protein requirement of Indian Butter catfish, Ompok bimaculatus fingerlings. Five iso-energetic semi-purified diets were formulated with varying levels of crude protein (25–45%) and fed to the experimental fish (3.29 ± 0.01 g) twice daily at satiation level in triplicate groups. Fishes were reared in indoor tanks with a stocking density of 11 fingerlings per tank. The results showed that the growth of the fish increased significantly (P < .05) with increasing protein levels upto 35% and decreased thereafter. Highest (P < .05) weight gain (247.25 ± 5.76%), carcass protein content (16.78 ± 0.04%) and protease activity (0.46 ± 0.02) coupled with lowest FCR (1.62 ± 0.04) were observed in the fish fed with 35% protein. PER and ANPR were found to decrease with increasing dietary protein levels (P < .05). Based on the second-order polynomial regression analysis of WG, it may be concluded that the dietary protein requirement of O. bimaculatus is 36.11% with a P/E ratio of 23.11 g protein MJ⁻¹ as indicated by the maximum growth.

KEYWORDS:

• Ompok bimaculatus
• protein requirements
• growth
• feed utilisation
• digestive enzymes
• proximate composition

Acknowledgments

The authors are thankful to the Department of Biotechnology, Ministry of Science and Technology, Government of India, for research grants under the center of excellence in fisheries and aquaculture biotechnology project. The authors are also thankful to the Vice Chancellor, Central Agricultural University, Imphal, India for his encouragement and providing facilities to carry out these research facilities.

Disclosure statement

Authors declare no conflict of interest.

Additional information

Funding

This work was supported by the Department of Biotechnology, Ministry of Science and Technology, Government of India [CAU/COF/2018].