Farmers, scientists reel off strategies for optimal fish productivity
CHARLES MADUABUEKE x-rays best pond management practices in fish farming for proper understanding necessary for enhanced productivity and profitability.
Aquaculture farmers and experts have enumerated factors that boost fish farming as good water management, feeding, and stocking source, among others.They described fish farming as raising fish commercially within enclosures built in replica of their natural habitat with ultimate aim of being sold as food.
Fish farming is a lucrative agribusiness, they claim, but like any other business, certain conditions must be met, just as there are challenges to tackle and precautions to be taken.
In Nigeria, fish represents a very important dietary element and a source of animal protein. Therefore, there is a substantial market for any amount of harvest and only in an optimized capacity can a farmer tap into this huge opportunity.
Chief executive officer of Ruby Farms Plus Home Essentials, Oluwadamilola Owoade, in a chat with The Guardian, talked about best practices that should be employed to maximise productivity. “There are different types of pond namely, earthen, concrete, tarpaulin ponds,” she said.Site selection of a pond is important, as this determines which type of pond to adopt with your culture system. Factors that will help in deciding site and culture systems are capital, availability of water, soil suitability and topography.
On merits and demerits associated with each type of pond, Owoade said, “Earthen pond is nice. This is because phytoplankton and zooplanktons are available as additional sources of food, aiding feed conversion rate and reducing cost of feeding, unlike in concrete pond. Artificial feeds are the only source of feed in concrete ponds, and this is costly.”
Aquaculture experts noted that in earthen ponds, wastes from fish and remnants from feeds are readily absorbed by the soil, thus water management is easier as there is little need to change water as done in other types of ponds. Concrete ponds, for instance, have an impermeable floor surface and to maintain good hygiene, the pond needs to be flushed as frequently as possible.
Also, the Ruby Farm boss said that feed conversation rate, cannibalism, diseases and death rate are easily observed in concrete and tarpaulin ponds and these are attributed to the frequent change of water in both types of pond, therefore this is a comparative advantage over the earthen pond.
Principal fisheries research officer at the Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta (FUNAAB), Mr Tunde Adeniyi, in a chat with The Guardian, said that to optimise productivity, some factors should be considered. He harped on culture system, specie selection, local sourcing of feeds and marketability.
Mr. Adeniyi said that this decision is based on available capital. “An experienced fish farmer that has access to swampy or waterlogged area might view earthen pond as a cheaper alternative to other type of ponds and will get optimum yield with best routine pond management. On the other hand, another farmer who’s looking to stock a larger capacity of fish and have the resources to make this happen will tilt towards concrete ponds,” he said. It is also important to note that if earthen pond is your preferred choice, there is a limitation to access. Mr. Adeniyi therefore opined that to optimize productivity, uniform sized fingerlings or juveniles should be stocked and the reason is that after stocking, it will be difficult to totally drain the pond and do sorting. Nonetheless, if your pond is in a water body path, proper drainage mechanism should be constructed to prevent flooding.
Specie selection, size and quantity to stock
MR. Adeniyi said that it is important to either talk to an expert that understands the biological characteristics and market acceptability of the artificial farmed fishes or be an expert yourself, as this will help in choosing which breed to farm to enhance profitability. Catfish and tilapia are major farmed fishes in the country currently, and both exhibit different behavioural attributes.
Catfish, for instance, is cannibalistic in nature while tilapia has a high reproductive rate. Pieces of information like these are handy for a profit minded entrepreneur, as decisions of what specie and quantity to stock as well as the holding capacity will be made with this knowledge.Adeniyi added that size depends on management, but juveniles are the best. “To raise a single catfish to a marketable size, he said, costs between ₦N350 to ₦N700, and this should be a determinant in the quantity to stock.” In addition to this, getting a good source for juveniles is of utmost importance, said the Ruby Farm boss.
“On my first attempt, I stocked about 750 catfish juveniles but I was only able to harvest a measly 40 per cent due to a high mortality rate of 60 per cent and this was because of where I sourced my post-fingerlings from,” she said. She subsequently changed her source, and maintaining the same practices, stocked 1,200 catfish juveniles and this time, she was able to harvest over 83 per cent.
OWOADE said that chemically treated water negatively affects the fish, therefore it is advisable to use a quality borehole water and in sufficient quantity for concrete or tarpaulin ponds and flowing river/stream water in earthen ponds. Also, the water temperature, pH level and dissolved oxygen level should be monitored intermittently as any irregularity undetected could be harmful to the fishes.
Experts say that pH of the water should be between 6.5 and 9.0 and if the pH is too low, add lime to the pond. In concrete ponds, Mr. Adeniyi said, “it is advisable to drain and change the water at least once a week, during which the fish can be numbered and sorted according to sizes, hence, additional tank is needed for the separation.”
THE FUNAAB research officer was of the opinion that feeding is the most important factor in fish productivity, as proper feeding in combination with excellent culture system helps optimise weight gain.He said, “It is pertinent to note that feeds consume about 50 to 70 per cent of the capital in an efficient farming system,” adding that most of the feeds are imported and expensive, but if locally produced, feeds could be cheaper, cost-cutting.
“In the past, the preferred fish feed was Coppens but now we have locally produced feeds that have been tested and confirmed to be very good.” Apart from proper feeding of the fish, extra attention should be paid to their feed conversion rate, feeding habit, energy and stress level. Fish with higher feed conversion rate will tend to be larger in size and as such, more aggressive. This set of fish should be separated from the smaller ones to avert cannibalism. This behavioural pattern is prominent in catfish.
In terms of feeding habit, some fish are bottom feeders (catfish), while some are top feeders (tilapia), and when feeding, one should ensure that time, place, quality and quantity of feed is maintained as disruption may induce stress to the fish.
Harvesting and marketability
A farmer should know the maturity period of the specie being raised and the target market for the fish right from the beginning. This will help the farmer to avoid impulsive selling and allow the fish reach a mature age, as it is the bigger, the better in fish business. Hotels, restaurants, bush bars, grill lounges and homes present a large market for fish and with this in mind, all the farmer needs after meeting a targeted optimized output is an excellent marketing strategy and branding.
The Ruby Farm boss said that it takes her four to five months of intensive feeding to produce table sized fish of approximately 1kg and this she sells out because the market is readily available.“It is faster when I decide to sell the stock alive. I can sell an entire pond of maybe 1000 or 2000 catfish in two weeks at most, and those I decide to smoke (smaller ones) take me about three months to sell,” she said.
Fish of 500g size or less are mostly smoked and sold at the dry fish market, while 500g to 2.2kg sized fish are sold to those who demand medium size fish, while 2.4kg fish and above are sold to those who prefer extra-large fish.Good feeding and feeds, water management, cost-profit analysis and market strategies are of utmost importance as these are catalysts to profitability.
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