Nutritive evaluation of fish acid silage in Labeo rohita fingerlings feed

Viscera of various fish species was collected during local harvest at the Department of Fisheries and Aquaculture, Ravi Campus, University of Veterinary and Animal Sciences, Lahore pond facility. Acid silage was prepared by systematic applications of formic acid. The proximate analysis of the product revealed 5.16 +/- 0.65% moisture, 32.17 +/- 0.12% crude protein, 9.56 +/- 0.14% lipids and 6.50 +/- 0.32% ash contents. Total microbial aerobic plate count was 1.69 x 10(4)+/- 0.06 x 10(3) cfu g(-1) while the coliforms were recorded as 0.97 x 10(4)+/- 0.02 x 10(3) cfu g(-1). The pure silage was free of aflatoxins B-1, B-2 and G(1) and G(2); however, microbial load and aflatoxin values vary in different feed ratios. The feeding trial showed significant change in all three feeds prepared from different ratios of silage; nevertheless, feed containing 75% acid silage showed better growth in Labeo rohita fingerling diet when compared with its counterparts. Our studies suggest that the fish silage can be a cheaper and effective alternative to fishmeal in fish feeds, if carefully handled and properly processed. This is because fish silage is prepared from fish waste body viscera, which is utilized neither in human nor in animal feeds in the raw form. On the other hand, fishmeal is a main and expensive ingredient used in livestock and fish feeds. Utilization of fishmeal is on the rise while its production is on decline, which is continuously escalating its price. Furthermore, the manufacturing of fish silage is simple and requires relatively lesser inputs as compared to fishmeal manufacturing.