Tips on Catfish Farming in Nigeria

Cat fish farming has become a major investment in the fish farm business in Nigeria. The major operations involved are nursery and grow-out operations. Nursery operation involves nurturing of the fingerlings for 3-4 weeks to juveniles and the grow-out operation involves rearing under a very good ecological and feeding condition to grow to market size which is suitable for consumption and sale. It takes 4 – 5 months from nursery to table size and up to six months for total harvesting in the pond in preparation for restocking.

Planning and Building Project

1    Land Acquisition and Location:  The factors to consider include;

      Good access road

      Existing aquaculture

      Closeness to the market and labour

      Regular water supply and drainage

      Nearby hatcheries

      Availability of good quality feed

      Presence of competitors around

      Types of fish people demand

2   Pond Planning: This has to do with the size and type of the pond and                      whether the operation is for     

     small scale or large scale.

There are two kinds of ponds

     Earthen pond

     Concrete pond/ Plastic pond

3   Production Planning: This covers feeding, water management and production      process

Feeding

Factors to consider:

Number and weight in the pond

Fish size

Water quality

Weather

Cropping should be done in batches – according to the sizes. The smaller the size, the less aggressive they feed. It is better done this way to avoid over feeding which may  add more wastes into the pond thus reducing water quality.

Feeding rates

It is better to feed them at high rate but not more than the amount they really need. Feeding them optimally results in: high production, good weight gain and to ensure higher feed conversion rates.

Feeding Frequency

There are two schools of thought on this: once daily and two times daily

1        Once daily could be adopted if the fish are fed to the satisfaction

2        Twice daily if wastages can be avoided,  and as well to ensure better feed    conversion

Feeding once daily may extend the production cycle and reduce the yield or the net production whereas feeding twice daily has been found to increase labour cost and reduce aeration if wastages are not controlled.

The feed are in the form of floating pellets to reduce waste and allow you to know how much the fish are taken daily. When feeding the fish, broadcast the feed over a wide area to allow all fish equal access to it and make sure the feed is enough to be taken for 30 minutes. Complete feed should consist of animal by products, vegetables, vitamins A, B12, D, E and K, riboflavin, thiamin, folic acid, nicotinic acid panthotenic acid and minerals.

Maintenance Feeding

This is applicable when the aim is not to gain or loose weight. Fish are fed with  maintenance ration daily  or fed with enough complete feed once or twice daily for once or twice in a week.

Feeding Time

Feeding has been found suitable early in the morning especially during the warn weather and in the evening close to nigh the dark,  this is because the cat fish have been observed to be in the peak of oxygen demand some hours ( 8 – 12hrs) after feeding.

Water Management

Water availability is considered in terms of quality and quantity and the sources can be from stream and borehole, borehole water has been discovered to be the best for the cultured fish. Good quality water should be supplied and to ensure this water can be analysed to determine the following parameters:  dissolved oxygen, turbidity (thickness and clarity of water), the pH (pH of 6.5 - 9 is good for fish), odour, colour, temperature (should be 27 - 32⁰C), pollutants ( oil spill, petrochemicals, detergents and agro chemicals) and pathogens.

Services of expert can be required to analyse these parameters to determine suitability of water for fish production. Cat fish requires some water movement , and as a result there is need for water change in the course of production. In the earthen pond water springs up from the ground and provides for the fresh water required by the fish. For fish to enjoy fresh water similar to what is obtainable from the streams, water in the concrete pond should be changed at the appropriate time to replenish oxygen and make the environment convenient.

The dept of water is considered as it influences availability of oxygen. The appropriate depth of the fish pond should be between 1.0m at the shallow end to 2.4 meters at the deep end. Ensure that oxygen level is adequate. Dissolved oxygen level should range between 4 – 5 mg/litre, a measure fallen to 3mg/ litre and below is not good and this gives a signal that water should be changed by draining the pond and supplying fresh water.

 Production Process

The aim is to produce fingerlings. Fingerlings can be produced naturally or artificially by influencing some natural conditions. On natural production, little or no efforts are required on providing for brood fish on mating and fertilization unto hatching to fingerlings. Fertilized eggs can be moved to hatchery and eggs placed to hatch 5 – 8 days of incubation to fries.

Fries are fed up to 6 times daily on complete and suitably sized feed 4 – 10 days before being transferred to a nursery pond to grow to fingerlings. Fingerlings are stocked and fed daily to reach market size. Artificial Fertilization and hatching requires specialized skills in: choosing male and female stock, injecting the female fish, sacrificing the male to obtain the sperms, stripping the eggs of the female, mixing sperm with the eggs, putting the fertilized eggs in hatchery and care of the fries.

Fingerlings Production

To ensure that fries grow faster they must be stocked at the lower rates. More space will be needed as they grow to fingerlings. The fingerlings can either be allowed to grow out in the nursery pond or transferred to the grow-out pond to grow to bigger sizes.

Feed size and Quality

The fries are given finely grounded feed once or twice daily. The particle size must be increased as they grow and increase in sizes. The feed should be in small pellets rich in protein, 32- 35% crude protein.

Stocking Rate

Fries are usually stocked at high densities 40,000 – 60,000 fish/acre and fingerlings are moved to grow-out pond at the lower densities according to the sizes. Fingerlings must be stocked at 10 fish/m² and thin out at regular interval as the size increases.

Cropping System 

This refers to the stocking – harvesting – restocking schedules. Fingerlings are stocked and allowed to grow to desired sizes and all fish are harvested before the pond is restocked with new fingerlings to start the next production cycle. After the fingerlings have been stocked they will be observed for growing ability and the ones growing faster are selectively harvested by a large seine net and stocked separately to prevent under feeding of those with lesser ability.

Farmer must ensure optimum production by adopting maximum fish population over the production period. Depending on the facilities and resources that are available, stocking densities of the fingerlings should range from less than 500 – 10,000 fish/acre. The size of fingerlings to stock is determined by factors such as cropping system, stocking densities and availability of fingerlings.

Make sure fingerlings are moved to grow-out pond as soon as possible to prevent infectious diseases and losses to predators.

Operations before Stocking the Pond

Disilting, Liming and Fertilization

Disilting: This is removal of mud in the pond after harvesting and draining has been done in preparation for new stocking.

Liming: This is application of lime to the pond after harvesting and desilting have been done. It is done to destroy parasites harboring in the pond. Liming helps break up the life cycle of parasites by destroying their eggs, larvae and pupae before new stocking. Also liming can be done when the pH of water in the pond is low. Limes being used are: CaC0₃ (applied at 300-500kg/ha), Ca0 (200kg/ha) and Ca(0H)₂ (200kg/ha).

Fertilizer Application: This is done after liming and it is done by spreading fertilizer in the pond to promote growth of zoo planktons which are natural fish food. There are two types that can be applied, organic and inorganic fertilizers. Examples of the organic are NPK, Urea and Potash. The inorganic are those from poultry droppings, and manure from other animals. Organic fertilizers can be applied continuously with liming whilst the inorganic must not be applied continuously because of chemical interaction with available phosphorus. Fertilizers are applied in the following rates:

Organic fertilizer;

NPK 25kg/ha

Urea 23-25kg/ha

SSP  23kg/ha

Inorganic fertilizer;

Cow dung 5000kg/ha

Chicken manure 3000kg/ha

Pig manure 3000kg/ha

Factors affecting Fish Growth

These are stocking rate, quantity and quality of feed, and water quality.

Fish Diseases and Predators

Fish Disease: Disease is unwholesome condition that causes ailment or death. Diseases are caused by microbes:

            Bacteria

            Fungi

            Virus

            Protozoa

Microorganisms are pathogenic when their population is large enough to cause diseases

 

Fish Predators:

The categories include:

            Birds -  kingfisher bird and heron,

            Reptiles -  alligators, water snakes

            Amphibians -  frogs, toads, crabs

            Mammals -  poachers (human beings)

            Insects - water beetles, water bugs etc.

Factors Promoting Disease infection: These are

            Overstocking

            Wounds

            Presence of dead matter in the pond

            Low amount of dissolved oxygen

Disease Symptoms include the following:

            Darkening of the skin

            Loss of appetite

            Clustering in the pond and trying to jump out

            Visible red or brown spot on the skin

            Sluggish or slow movement in the water

Prevention of diseases is done by the following:

*Stock the fish at the recommended rates.

*Do not apply too much fertilizer in the pond to avoid algae growth.
*Feed adequately and regularly and at appropriate proportions.

*Change the water regularly.

Control of predators is done by doing the followings:

*Fencing with wire mesh to prevent toads, frogs and reptiles from entering the pond.
*Allow the pond bottom to dry after harvesting to kill all living organisms in  the mud.
*Screen the inlet pipe properly and cover with fine net and wire mesh to prevent entrance of predators.
*Put good security in place.

Pond Maintenance 
This includes pond sanitation and repairing worn-out embankments or dykes. Aquatic weeds should be weeded regularly because they harbour predators, hinder fish movement, and they are sometimes toxic to the fish. Weeds can be controlled biologically using tilapia fish which are herbivores - feeding on the vegetation.

Harvesting

This is removal of fish from the pod and it can be done 4 – 6 months depending on the production target and to meet up with some other needs of the farmers. Catfish are harvested by using nets. Different types of nets are used depending on whether farmer wants partial or total harvesting. During harvesting handle fish properly and don't injure them. Also, get all harvesting materials ready and make sure potential buyers are ready. Harvest during the cool period of the day and do not feed them a day or two days before harvesting to prevent stress which might result in death during transport.

Harvesting tools: These are two main types:

*Active fishing tools – Beach seine net or dragnet, scoop net and cast net

*Passive fishing tools – Gill net, hook and line and the trap net