Effect of Organic Fertilizers on Zooplankton Production
Comparative study of zooplankton production, using poultry droppings, pig dung and cow dung was carried out for five weeks using seven glass aquaria (60×30×36) cm³. The aquaria were thoroughly washed, filled with 20litres of bore-hole water, fertilized with the respective organic manures after 4 days fermentation and inoculated with zooplankton samples collected from an earthen fish pond. The highest mean zooplankton population was recorded in the aquarium tanks fertilized with poultry droppings (3989cells/L), followed by pig dung (2783cells/L) cow dung (2030cells/L) and lastly the control aquarium (1140cells/L). Poultry droppings culture had the highest population peak in the second week (8175), pig and cow dung in the third week (5650,4225) and the control in the fourth week (2350). Poultry droppings is therefore recommended for quick and high production of zooplankton which invariably reduces the high cost of imported expensive pelleted feed for fish fry.
KEY WORDS: Organic fertilizers, Zooplankton, Production.