SILAGE PRODUCTION FROM SALMON FARM MORTALITIES

Fish silage was made from salmon farm mortalities. Citric, formic and propionic acid, as well as combinations of these acids, were used as ensiling media. Stability, liquefaction rate and soluble nitrogen contents were studied. The silages made with 2 or 3% (w/w) of citric acid alone were unable to achieve stability, while the pH increased from 3.8 to 4.5 by day 30 for the 4.5% (w/w) citric acid silage. The pH for the other acids and for the acid combinations was very stable. All of the silages liquified quickly for the first ten days, and then liquefaction levelled off. The amount of soluble nitrogen increased for all the silages, as did the percent liquid. The results indicated that salmon farm mortalities could be used as the raw material in the production of fish silage and a marketable liquid fertilizer.