PRODUCING QUALITY FISH FEED

PRODUCING QUALITY FISH FEED

NUTRIENT REQUIREMENT OF FISH

        In Nigeria fish farming, two main fishes are involved. They are catfish and tilapia. Although, there is a recent tendency to diversify into carp and heterotis production. Catfish require 28-35 and 45-50% cp and tilapia 25-40%cp depending on their age. The older they are, the lower the crude protein requirements. Therefore the fry of catfish require 45-50% cp, the fingerlings and juveniles require 40-45% cp while the broodstocks requires 35%cp. The fry of tilapia require 40%cp while the adults require 25-30%cp. The two tables below contain some nutrient required and their values for some fishes.
           Feed for fish must meet all the nutrient requirement of the species and this is achievable through diet formulation procedures.
The formulator selects dietary ingredients with predetermined upper and lower limits of inclusion, to form a mixture that is pelletable, palatable, nutritious, inexpensive, free from antinutritional factors, storable, transportable, usable and water stable.
                 Dietary ingredients are chosen based on cost, availability, chemical composition and nutritional value.
Digestibility of the ingredients is also very essential

FEED FORMULATION

A balanced diet can only be obtained through feed formulation. Feed formulation can be carried out through different methods, which include:
1) Pearson’s square method
2) Algebraic method
3) Trial and error method
4) Linear programming which employs the idea of least cost feed formulation using computer.

Most nutritionists often depend on trial and error method.

COST CONSIDERATION

If sesame seed meal cost #70/kg and contain 44% cp;
Cost/kg of protein             =     70     
                                                  0.44          =          #159.09/kg protein
If groundnut cake cost #60/kg and contain 40% cp
Cost/kg of protein             =        60   
                                                     0.40       =           #150.00/kg protein

                       Thus, although the groundnut cake has a lower protein content, it is still a better buy as its cost is less per kg of protein supplied. Similar calculations can be carried out for any other given nutrient to find the least cost feedstuff for supplying such nutrient.

PRODUCING THE FEED FORMULATED

*Acquire the ingredients
*Process the soyabean
*Mill all that need to be milled
*Weigh each ingredient appropriately
*Mix all together without starch thoroughly
*Cook the starch
*Mix the cooked starch with cold water and mix with the mixed feed to moist for pelleting
*Dry after pelleting
*After drying, bag it and it is ready for use.
The feed should be stored in a cool and dry place

FEED CONVERSION AND EFFICIENCY CALCULATION

Because feed is expensive, feed conversion ratio (FCR) or feed efficiency (FE) are important calculations for the grower. They can be used to determine if feed is being used efficiently. FCR is calculated as the weight of feed fed to the fish divided by the weight of fish growth.
FE is simply the reciprocal of FCR (1/FCR). FCR of 1.5 or 2.0 and FE greater than 50% are considered good growth.

FEED CARE AND STORAGE

Bags of feeds should be kept out of direct sunlight and as cool as possible. Vitamins, proteins, and lipids are especially heat sensitive, and can be readily denatured by high storage temperatures. High moisture stimulates mold growth and feed decomposition. Avoid unnecessary handling and damage to the feed bags which may break the pellets and creates fines which may not be consumed by fish.
                 Feed should not be stored longer than 90 to 100 days, and should be inventoried regularly. Bags should not be stacked higher than 10 at a time. Older feed should not be used first, and all should be regularly inspected for mold prior to feeding. All moldy feed should be discarded immediately. Mice, rats, roaches and other pests should be strictly controlled in the feed storage area, because they consume and contaminate feed and transmit diseases.

MEDICATED FEEDS

When fish reduce or stops feeding, it is a signal to look for problems. Off-feed behavior is the first signal of trouble such as disease or water quality deterioration in the fish growing system. Relatively few therapeutic drugs are approved for fish by FDA, but some medicated feeds for sick fish are available. Although using medicated feeds is one of the easiest ways to treat fish, they must be used early and quickly because sick fish frequently will stop feeding.