FISH feeds are formulated to meet the nutritional requirements of different fish species and different stages of their growth. For instance, baby fish needs more nutritious food, such as more protein and energy than adult fish, while catfish may need more protein than tilapia.
The size of the feed pellets also depends on the size of the fish as small fish eat powder and small pellets of less than 1 millimeter (mm), while a fish of 500 grammes can feed on six to eight mm pellets.
“Thus, feed formulation is a technical field, depending on the size of fish you farm,” said the Research Officer-Fish Nutrition at Kajjansi Aquaculture Research and Development Centre of Uganda National Fisheries Resources Research Institute (NaFIRRI) in Kampala City, Mr Denis Opio.
He was educating officers and fish farmers of Ilemela District of Mwanza region, Tanzania, who paid a visit at the Center for fish farming knowledge gain, including how best to prepare the quality fish feeds.
The tour was organized by the Tanzanian High Commission in Uganda and Lake Victoria Fish Organization (LVFO), last month. Mr Opio explained further that there are a range of raw materials that can be categorized as protein sources, energy/carbohydrate sources and additives.
Much of these can be locally sourced, others are imported. Local protein sources include, Silver cyprinid or dagaa (in Tanzania and Mukene in Uganda), Haplochromine fish, (Nkejje in Uganda and fulu in Tanzania) as well as Fresh water shrimp (CaridiniaNilotica). Others are Black soldier fly maggots, Abattoir waste, including blood meal as well as Agro-industrial by-products such as soybean cake, sunflower cake and cotton seed cake.
“Imported protein sources include Blood meal, Feather meal, Meat and bone meal and Corn gluten meal. These are also available on the Ugandan market,” he said, adding that: Carbohydrate sources can be sourced locally, including Wheat bran, Whole maize, Maize bran, Wheat pollard and Rice bran, among others.
Feed additives supply nutrients that are not available in or in some way lacking in the above ingredients. They also serve other roles in feed quality, acceptability and shelf-life. Some are Vitamin/mineral premixes to supply extra minerals and vitamins, Antioxidants to preserve the shelf life of the feeds, as well as Antufungals to preserve the shelf life and keep the feed safe from aflatoxins.
There are also Attractants to draw the fish to feed and Aflatoxin binders to prevent fish from being poisoned by aflatoxins. These additives are mostly imported from outside East Africa, according to him. Kajjansi Center has two fish feed processing plants, where the old one was able to produce about one metric tons of sinking pellets per day or 30 tons per month.
There was also a newly launched production line that can produce eight metric tons of floating feed per day. Commenting on how much one can invest in a feed manufacturing plant, Mr Opio said that the investment will be determined by the size of capital, intended production capacity, availability and cost of power, space for factory premises, stores and demand for feed, among other factors.
For as little as USD 3,000, one can invest in a small extruder capable of producing 300 kilograms per hour of fish floating feeds. Sinking feeds can be made using simpler equipment at a much lower cost, such as 800 to 1500 USD. A complete production line can cost from 25,000 up to 200,000 USD depending on capacity and build.
“Note that big equipment requires 3 phase power while the very smallest ones can run on diesel. Floating feeds are made using a special piece of equipment called an extruder that runs at high temperature and pressure,” he said.
Fish sinking feeds are made using ordinary pelleting machines. The cost of production of floating feeds is higher than that of sinking feeds which makes floating feeds more expensive, and they are preferred by most farmers.
It was further noted that lack of some important additives, locally, in Uganda and Tanzania, is among the causes of high costs in fish feeds.
Again, lack of feed processing plant in Mwanza is also a reason behind high costs of fish feed. As a result, over 70 per cent of fish farm operating costs is for feed, a situation that seems to be a serious challenge to small fish farmers in Tanzania.
Given the fact that fish farmers in Mwanza are in groups, then the government should empower them through installation of a feed processing plant and let the members make the refund in every fish harvesting season, advised the Tanzanian High Commissioner in Uganda, Dr Aziz Mlima.
It should be a larger plant that will be serving all fish farmers in the Lake Zone, so as to promote mass fish production on Lake Victoria.
“The 200,000 to 250,000 USD is a huge amount to fish farmers, but the government can set an enabling environment for them, through giving the plant in a loan basis,” he clarified.
The Tanzanians also had time to visit the Masese Cage Fish Farmers Co-operative Society in Jinja City, observing how fish cages were operating on Lake Victoria.
One of the Cooperative leaders, Ms Naima Abdallah, urged the visitors to go for the use of round-shape cages, which occupy small space but accommodate mass fish. However, she cautioned that the round cages are somehow expensive compared to that of rectangle shape because the former consumes lots of raw materials.
“We are thankful that our government supports us through loans and we usually clear the debts in time so that we can be given more and more funds to expand our capitals. But, we are facing a lack of quality fish feeds. They are expensive and unaffordable to most of us small fish farmers. The markets are everywhere for our products, mostly fish mongers,” she said.
Once again Dr Mlima urged the Tanzanian government through vocational education and Training Centers (VTC) to make the round-shape cages available to farmers, in terms of loans. VCTs should get in contracts with fish farmers’ groups for cage manufacturing and let the loners make the refund, in installments, during fish harvest seasons.
“And let our policies upgrade all fish farmers so that the sector can, at larger extent, contribute to personal and nation’s economy,” urged Dr Mlima.