PHYSICAL AND NUTRITIONAL PROPERTIES OF MOIST FERMENTED FISH SILAGE PELLETS AS A PROTEIN-SUPPLEMENT FOR TILAPIA (OREOCHROMIS-NILOTICUS)

Fish silage was prepared by fermentation of stunted tilapia with 50 ml /kg Lactobacillus plantarum starter culture and 150 g/kg sugar beet mo lasses at 30 degrees C for 7 days, pasteurized, neutralized, and store d at 30 degrees C for 180 days. Addition of 50 ml/kg onion extract pro ved effective as lipid antioxidant, with peroxide values lower than th e control (P < 0.05). The wet silage was mixed (2:1, w:w) with poultry by-product meal, soybean-hydrolysed feather meal blend or menhaden fi sh meal; and each mixture pelleted by cold extrusion method. The moist pellets maintained a firm consistency during water immersion for 10 m in and pellet stability was similar (P > 0.05) among diets. Protein an d lipid losses were low (< 15%) on a per gram diet recovered basis. Al l-male Oreochromis niloticus fingerlings (mean weight, 56.2 +/- 3.7 g) were fed each pellet at 4% of body weight/day for 15 days in a recirc ulated system (temperature, 27 degrees C; flow, 3 1/min). Apparent dig estibility coefficient (ADC) for dry matter, crude protein and gross e nergy of the pellets were high (> 80%) and similar (P > 0.05) among di ets. Moist fish silage pellets were physically stable and highly diges tible to O. niloticus, and suitable as farm-made feeds for fish. (C) 1 998 Elsevier Science B.V.