CHEMICAL AND NUTRITIONAL QUALITY OF DRIED FERMENTED FISH SILAGES AND THEIR NUTRITIVE-VALUE FOR TILAPIA (OREOCHROMIS-NILOTICUS)

Fish silage was prepared from whole juvenile tilapia by fermentation w ith 50 g kg-1 (wet weight, w/w) Lactobacillus plantarum at 30-degrees- C using 150 g kg-1 (w/w) molasses, com flour or tapioca flour as alter native fermentation (carbohydrate) substrates. After incubation for 7 days, a desirable and stable pH of less than 4.5 was attained and the source of fermentation substrate did not affect the soluble nitrogen c ontent or the proximate composition of the liquid silage after 30 days storage. Soya-bean meal, used as filler material, was blended with th e liquid silage in ratios 1:1, 2:1, 3:1, 3:2 (w/w) and oven-dried. The various proportions of fish silage:soya-bean meal improved the dry ma tter (DM) and nutrient composition of the silage after drying. The 1:1 dried fish silage was incorporated into dry pelleted diets (650 g kg- 1 diet) formulated for tilapia (Oreochromis niloticus). The pellets ha d a tough consistency and maintained their shape during water immersio n. Water stability of dried fish silage pellets were similar (P > 0.05 ) to that of a reference diet. Apparent digestibility coefficients for DM, protein and energy of the silage diet were 82.8%, 84.5% and 82.8% , respectively. It was concluded that co-dried fermented fish silage i s suitable and has a potential as a protein feedstuff in fish diets.