D. Nguenga
Institute of Animal Research (IRZ)
Foumban Piscicultural Research Station
P.O. Box 255, Foumban, Cameroon
Abstract
An experiment was conducted at the Foumban Piscicultural Research Station in order to evaluate the efficiency of chicken manure on fish yields. The polyculture was composed of Tilapia (Oreochromis niloticus) and African catfish (Clarias lazera). Three 400-m ponds were used and loaded with 1.75 fish/m² . Chicken manure was applied at a rate of 40 kg dry matter per hectare pond per day at the start of the experiment. Waste allowance was adjusted biweekly with an addition of 20 kg dry matter/ha. Ponds were manured 6 days a week. Cow manure (150 kg dry matter/ha) and mineral fertiliser, NPK 20, 10 and 10 (100 kg/ha) were applied alternatively at 2-week intervals in order to strengthen the effect of chicken manure. Throughout the experimental period no other supplemental feeds were added to the ponds. Additional water was only added to replace losses due to seepage. The mean survival rate was about 66%. Fish kills were probably due to predation by birds during the dry season. The total fish biomass was 3.4 tonnes per hectare per year. This zootechnical value reveals that Tilapia and Clarias can thrive on natural foods (the manures and NPK used) in ponds (zooplankton and phytoplankton) without other supplemental feeding.
