TITLE:
Evaluation of Nitrogen and Phosphorus Wastes Produced by Nile Tilapia (Oreochromis niloticus L.) Fed Azolla-Diets in Earthen Ponds
AUTHORS:
Youssouf Abou, Aliou Saidou, Daouda Mama, Emile D. Fiogbé, Jean-Claude Micha
KEYWORDS:
Azolla; Aquaculture; Environment; Fish Meal Replacement; Oreochromis niloticus; Nitrogen; Phosphorus; Nutrient Balance
JOURNAL NAME:
Journal of Environmental Protection,
Vol.3 No.6,
June
21,
2012
ABSTRACT: Nitrogen (N) and phosphorus (P) wastes produced by Nile tilapia Oreochromis niloticus L. fed Azolla, an aquatic atmospheric nitrogen fixing fern, was evaluated for 90 days in pond experiment. Six isonitrogenous (29.2% crude protein) and isoenergetic (16.9 Kj·g–1) diets A0, A10, A20, A30, A40 and A50, containing 0%, 10%, 20%, 30%, 40% and 50% of Azolla meal (AM) respectively, as partial fishmeal (FM) substitutes, was provided to experimental fish. The Azolla-free diet A0 served as a control. Fish specific growth rate (SGR) was higher with the control diet, the lower values being obtained in A50-fed fish (P Azolla could be used in diet to sustain Nile tilapia growth and as “environmentally-friendly” ingredient to limit P loss, while providing N to the field, beneficially in tropical marshland pond where this nutrient is already limiting.