Efficacy of biogas slurry in carp, Cyprinus carpio var. communis (Linn.), culture—effects on survival and growth

Abstract

Effects of biogas slurry, a by-product of biogas plants, on the survival and growth of common carp, Cyprinus carpio var. communis over 270 days of culture were determined. Growth rates of the fish (in terms of weight) were 3·54 times higher in biogas slurry-treated tanks than in controls. Supplementary feeding (with rice bran: groundnut oil-cake, 2:1 at 2% of the body weight) further increased growth rates to 5·70 times higher. Biogas slurry was a better fish pond manure than raw cowdung, for growth rates of common carp in raw cowdung-treated tanks were only 1·18 to 1·24 times higher than in the control. A strong positive correlation existed between length and weight of fish in all treatments.