Feed formulation is an integral part of catfish farming business, especially in tropical Africa. This is due to the fact that imported fish feeds are always expensive due to the cost of logistics on importation and weak local currency, making the cost of such products skyrocket.
The environment in Africa allows individual farmers to formulate feed for their fishes in order to reduce the cost of feed production and also to enjoy flexibility in choice of feed ingredients for feed formulation. It has been observed that majority of catfish farmers have little or no knowledge of this aspect of their business. As a result of this, many gamble and some even depend on the judgment/choice of their feed millers who are ready to exploit them for the purpose of making more profit. Little wonder that some farmers fail at this critical point.
Ideally, your choice of feed ingredient and formula should be guided by the following;
- Nutritional requirement of your fish stock
- The presence or absence of anti-nutritional or toxic factor
- Availability of preferred ingredient
- Palatability of available ingredient
- Cost and benefit of the available ingredients
- Available processing technology or method
Nutritional requirement of your fish stock: Adequate knowledge of ingredients and nutritional value of various ingredients, coupled with the nutritional requirement of your feed at various stages, will help you as a farmer to formulate a quality feed. From ingredients combined, it is possible to calculate the crude protein, energy, and fat in your feed either manually or by inputting it on a dedicated computer program.
The presence or absence of anti-nutritional or toxic factor: Some ingredients are better not used due to presence of certain anti-nutritional element(s) in them. For instance, Soya Beans grain must be well processed to remove some anti-nutritional elements in them. Some ingredients like GNC can also encourage the growth of Aflatoxin, although this may not be a major concern in catfish farming business unlike in poultry.
Availability of preferred ingredient: Certain ingredients are preferred over others. This might not be unconnected with cost and availability of such ingredients. When such ingredients are not available, a farmer is saddled with the responsibility of choosing from a wide range of similar ingredients. For instance, when flour or dough is not available, a farmer is faced with the challenge of choosing from energy grains or processed tuber crops to complement the energy requirements of the fish.
Palatability of available ingredient: An experienced catfish farmer understands that catfishes have taste preferences, and he will ensure that he chooses from a variety of ingredients that will suit the taste of his fishes. For instance, GNC has better taste and aroma over its substitute Bernseed, and soya meal is preferred above cotton seed.
Cost and benefit of the available ingredients: Cost factor, as well as benefit of the cost, is an important factor that must be well considered in feed formulations. The cost of 72% fish meal against its benefit might not make it the best alternative where local fish meal is available, especially in a situation where most of the imported fish meals in the market are adulterated. Also, there may be many ways to meet up with the protein requirement for your fish but animal protein, especially protein from fishes, must not be totally removed from the feed; the quality and quantity must be well sustained regardless of your choice of ingredient.
Available processing technology or method: This is a crucial factor to be considered when formulating your feed. Some ingredients should not be used at all due to crude processing method which might have led to the loss of essential nutrients. Maize should not be used at all if the feed miller does not possess the technology to powder it because experience has shown that fish might not be able to fully digest maize grain that is not well milled.
Nutritional Requirement for Catfish Feed
Catfish feed requires certain nutrients that will help the farmer optimize the growth as well as increase the profit on their catfish farming business. Below are the 4 classes of nutrients, in order of importance, essential in any feed formulation:
- Protein: This class of nutrient is required for building body tissue and replacement of damaged tissue. It contains physiological molecules such as hormones and enzymes. It can be obtained from plants and animals.
- Energy (Carbohydrate): This nutrition provides the energy needed for catfishes. Grains of cereals and cassavas are the major source of this nutrient.
- Vitamins and minerals: Growth, health, and body process are controlled by this class of nutrition. For example, organic and inorganic chemicals are found in vitamin and minerals.
- Fat: Fat contains vital fatty acids and also enhances energy delivery in feed.
There is a need to understand nutritional contents of available feed ingredients so as to understand and select appropriately ingredients that will meet the nutritional needs of your catfish. Each class of nutrition is analyzed separately below:
Nutritional Level of Animal Proteins
|Animal Protein||Energy Level (mj/kg)||Crude Protein (%)||Fats (%)||Calcium/Phosphorus (%)||Methionine (%)||Lysine (%)|
|Meat meal||11.2||50 – 51||10||8||0.7||2.6|
|Blood meal||15.2||88 – 90||1||0.4||0.6||7.1|
|Feather meal||13.7||80 – 85||7||0.4||0.6||2.3|
|Poultry meal||13.1||60 – 64||13||2.0||1||3.1|
|Fish meal||5||55 – 75||3||1.0||1.5||2|
Nutritional Level of Plant Proteins
|Plant Protein||Protein (%)||Energy (cal/kg)||Calcium (%)||Lysine (%)||Methionine (%)|
|Soybeans meal||44 – 48||2557||0.20||3.2||1.4|
|Cottonseed meal||40 – 41||2350||0.66||4.2||1.4|
|Sunflower Meal||46 – 47||2205||0.30||3.5||2.3|
|GNC||45.6 – 61.8||3860||1.7||3.2||1.0|
Nutritional Level of Energy Base Ingredients
|Ingredients||Protein (%)||Energy (cal/kg)||Calcium (%)||Lysine (%)|
|Maize||8 – 11||3200||0.5||0.27|
From the nutritional table of certain feed ingredients, a sample of simple catfish feed formula can be generated thus:
|Maize/Wheat/Cassava Flour (any of the three)||25kg|
|Soya/Sunflower/Cotton seed (Soya preferred)||30kg|
|GNC/Benseed (either of the two)||20kg|
|Fish meal (72%)||10|