The African bony tongue is present in river basins of sub-Saharan Africa, where it is exploited by fisheries. It has interesting potential for fish farming, such as a high growth rate, omnivorous diet, a commercial size of up to 7 kg and being valued for human consumption. In Africa it is exclusively reared in poly-culture in association with the Nile tilapia in extensive fish farming systems.
Escalation of aquaculture production requires the use of good quality feed. The quality of fish feed depends on the quality of the ingredients and nutrients and their ability to satisfy nutritional requirements. Fish and other animals need nutrients and energy to perform their vital functions. Dietary protein provides amino acids that constitute the preferential nutrients used for energy production in fish1.
However, the major sources of protein, such as fish-meal, remain among the most expensive ingredients used in the formulation of farmed fish feed. Therefore, a good balance between protein and energy level in the diet to achieve optimal fish growth at a minimal production cost is necessary. Protein requirements depend on fish size, age, physiological status, species and environmental conditions2.
Keeping in view the above mentioned scenario, researchers conducted a new study in order to determine the effect of dietary protein and energy levels on growth, feed utilization and body composition African bony tongue of juveniles3. An 80 day feeding trial was conducted in earthen ponds to evaluate the effects of dietary protein and energy levels on growth, feed utilization and body composition of fingerlings.
Results of growth performance and feed utilization showed that increasing dietary protein and energy level increased final body weight. Results of feed utilization showed that feed conversion ratio and protein efficiency ratio were influenced by dietary protein and energy levels. Feed conversion ratio improved with increasing energy content up to 30% dietary protein level, and, in this range of protein level, protein efficiency ratio increased with increasing energy content.
On the other hand, dietary energy and protein levels affected body lipid content in fish fed with a diet containing protein levels between 25 and 30%, whereas no significant difference was observed between fish fed with 35 and 40% dietary protein, regardless of the energy level in the diet.
It was established that African bony tongue fish juveniles were well adapted to breeding conditions in the hapas with better survival rates. It has been shown that dietary protein and energy levels affected growth and feed utilization. The suitable dietary protein and energy levels for optimal growth were found to be 30% and 19 mg kJ–1 respectively.
Heterotis niloticus, dietary protein, optimal growth, fish farmers, fingerling, African bony tongue, feed utilization, body weight, juveniles, protein efficiency ratio, feed conversion ratio, body composition.
- Zuanon, J.A.S., A.L. Salaro, S.S.S. Moraes, L.M.D.O. Alves, E.M. Balbino and E.S. Araujo, 2009. Dietary protein and energy requirements of juvenile freshwater angelfish. Rev. Bras. Zootec., 38: 989-993.
- Kim, K.W., M. Moniruzzaman, K.D. Kim, H.S. Han, H. Yun, S. Lee and S.C. Bai, 2016. Effects of dietary protein levels on growth performance and body composition of juvenile parrot fish, Oplegnathus fasciatus. Int. Aquatic Res., 8: 239-245.
- Goure-Bi, T.F., Ble, C.M., Etchian, A.O., Alla, Y.L. and Ouattara, N.I., 2018. Effect of Dietary Protein and Energy Levels on Growth, Feed Utilization and Body Composition of Juvenile African bonytongue (Heterotis niloticus). Pak. J. Nutr., 17: 627-633.