By Mustapha ABA, PhD, Researcher Aquaculture Fish Nutrition Morocco.
In aquaculture, as for all animal production activities, it is necessary to evaluate the parameters involved in nutrition management in order to achieve a balance between market, environment and quality. This sector aims to provide social and economic benefits that in turn result in the production of a high-nutritious food source.
It is important to emphasize that the development of the aquaculture activity is closely related to fish nutrition which directly affects the final quality of the product. In this context, aquaculture requires the optimization of nutrition to effectively raise fish for the purpose of producing good quality food.
However, the use of artificial feeds in aquaculture relies on an understanding of fish eating habits and their nutritional needs. The goal is to provide quality nutrients for development in a physically acceptable form for fish.
Nutritional requirements of fish in aquaculture
Diets for fish must provide all the essential nutrients and energy needed to meet the physiological needs of growing fish. Essential nutrients for fish are amino acids, fatty acids, vitamins, minerals and energy macronutrients (proteins, fats and carbohydrates).
- Protein is needed in the diet to obtain amino acids, which are used to synthesize new proteins or maintain existing proteins in the tissues while the excess protein is converted into energy.
- Lipids provide essential fatty acids and energy in the diet. Lipids are also important structural components of membranes and act as precursors of steroid hormones and prostaglandins in fish. In addition, fats affect the content of unsaturated fatty acids in fish.
- carbohydrates can be a source of energy for fish, but their ability to use dietary carbohydrates for energy varies depending on the species and their natural diet.
- Vitamins are organic compounds that play an important role in the life, growth and development of fish. The fish are unable to synthesize the vitamins that must be provided by the food.
- Minerals, based on demand for minerals, they are divided into 2 groups: macro and micro-minerals. They play an important role in the creation of functional groups of enzymes, hormones, in the regulation of protein biosynthesis.
Digestibility of nutrients
Nutrient digestibility in the diet can affect aquaculture, production efficiency and environmental impact. The bioavailability or digestibility of the diet is the proportion of nutrients in the food that is digested and absorbed by the fish. Data on digestibility and available digestible energy of food ingredients in fish diets are essential for optimizing food formulations. Poorly digested foods lead to limited growth and high nutrient excreta, which pollute the environment. Therefore, nutrient digestibility and nutrient and waste retention potential must be considered for efficient and sustainable animal production when reviewing food formulations.
Fish have the ability to use lipids for energy, saving protein for deposition and growth, so the inclusion of lipids in diets for fish is important for both growth and energy.
Most commercial foods today are formulated to increase growth performance by exploiting the effect of protein savings by high-energy lipids, allowing most of the dietary protein to turn into flesh.