Use of fish silage for partial or complete replacement of fish meal in diets of Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) [electronic resource].

Includes references.

Fish silage was prepared by fermentation of fish by-products with Lactobaci!lus acidophilus. molasses and rice bran. The ensilage process completed after 30 days and the fermented fish silage (FFS) was sun-dried for 3 days and incorporated into the experimental diets. Two growth trials were conducted to investigate the effect of partial or complete replacemenl offish meal (FM) by dried rennented fish silage (FFS) in diels of Nile tilapia, Oreochromis ni/orieus and African catfish, Clar/as gariepinus. Five dry pelleted diets containing 0, 10,20,30 and 40% FFS to replace 0, 25, 50, 75 and 100% ofFM (on prolein content basis) were prepared to be isonitrogenous (30% CP) and isocaloric (2600 kcal ME/kg diet) and lested in 3 months feeding two separale trials, Nile tilapia fry (2,57- 2.71 g) and catfish (3,98 • 4.03 g) were fed Ihe tested diets twice daily for six days a week in triplicate and duplicate groups of tilapia and catfish experiments, respectively. Results indicated that, dried FFS can successfully replace up to 25 and 50% of FM in tilapia and catfish diets, respectively without any significant loss in growth performance and feed utilization. The higher levels of replacement ofFM by FFS (50, 75 or JOO% in tilapia diets and 75 or 100% in catfish diets) significantly reduced growth performance, feed utilization parameters as well as significant effect on fish body composition of titapia and catfish. Apparently, FFS can be used efficiently as a protein source in Nile tilapia and catfish diets to reduce feed costs for the two fish species. From economic poinl of view, it was observed that replacing 25% or 50% of FM by FFS in Nile tilapia and catfish diets did not signiftcantly adversed growth or feed utilization parameters of Nile tilapi~ and catfish, respectively and this replacement reduced feed costs/kg diet and feed cosls1kg weight gain by 7,35 and 11.30%, for lilapia and by 15,59 and 19.39% for catfish. respectively.

Summary in Arabic.

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