Ajani EK, Orisasona O and Omitoyin BO
The use of poultry manure and maggot for pond fertilization and fish food respectively, are age-long aquaculture practices to improve productivity. This study investigated the bacterial load, and frequencies of occurrence in fish raised using poultry manure and maggot.
A total of 200 Clarias gariepinus (average weight, 150 ± 0.92 g) were each stocked into four earthen ponds (Dimension 20 × 13 m2, each). Ponds A and B were prepared but not fertilized, while Pond C and D were prepared and fertilized with poultry manure. Ponds A and C were fed commercial diet, while ponds B and D were fed maggot at 3% body weight for 6 weeks. Microbial assay of the culture water, skin and gut of experimental fish were carried out to determine the microbial load, species identification and frequency of occurrence. The effect on water quality parameters was investigated.
Results of the assay showed a higher bacterial count in the water sample, skin and gut of fish from C group (9.30 × 104, 2.50 × 104 and 2.11 × 106 cfu/ml/cm2/g respectively) while the least was recorded in B (4.43 × 102, 2.91 × 103 and 6.4 × 105 cfu/ml/ cm2/g for water sample, skin and gut respectively). Basillus spp., Staphylococcus saprophyticus, Escherichia coli, Salmonella spp. and Micrococcus spp were isolated from the fish and water, with high frequency of occurrence recorded for Salmonella spp, Bacillus spp and Micrococcus spp in the skin and guts of C and D groups.
The result of this study revealed increase in the bacterial load in pond water, fish skin and gut as a result of fertilization with poultry manure.