Toxicity (EC50) comparisons of some animal wastes

Toxicity of various animal wastes, after mixing with deionized water, for 1 and 24 hr, was measured using Photobacterium phosphoreum. The EC₅₀ values determined by the ‘microtox’ toxicity test showed that the aqueous extracts of all animal wastes were toxic and the toxicity increased in the order: cattle, horse, sheep, pig and poultry. The observed toxicity was found not to be influenced by the amount of kjeldahl-N, NO₃ or NH₄ present in the waste-extract.