Inclusion of different levels of solid-state fermented mahua oil cake on growth, digestibility and immunological parameters of rohu (Labeo rohita)

Abstract

Mahua oil cake (Bassia latifolia) is one of the non-conventional ingredients which are generally used as manure for horticultural crops. However, mahua oil cake can also be used as cheap source of nutrient for fish replacing conventional plant ingredient by solid state fermentation. Solid state fermentation of mahua oil cake was done by mixed strain of microbes (Sachharomyces cerevisiae and Bacillus subtilis) through a standard set of procedures which improved the quality of mahua oil cake by increase in crude protein, decrease in crude fibre and decrease in anti-nutritional factors like total tannin and saponin. To evaluate the fermented mahua oil cake in rohu, six iso‑nitrogenous feeds for rohu (Labeo rohita) were formulated and prepared incorporating fermented mahua oil cake at different levels i.e. 0, 10, 20, 30, 40 and 50% replacing soyabean meal and other feed ingredients and fed to rohu fingerlings in different treatment groups for 120 days period. Fish fed diets with 20% of mahua oil cake significantly improved (p < 0.05) growth performance, feed conversion ratio, digestibility of nutrients and immunological parameters like lysozyme, myeloperoxidase and haemagglutination compared to diets without fermented mahua oil cake. However, fish fed diets with 40% fermented mahua oil cake resulted non-significant difference (p > 0.05) in growth performance, nutrient digestibility and immunological parameters compared to diets without fermented mahua oil cake. The present study might suggest incorporation of solid state fermented mahua oil cake up to 40% level without interfering growth, digestibility and immunological parameters in L. rohita fingerlings.