Abstract
Due to inconsistency in demand and supply of fishmeal there is immense need of alternate protein sources. Present project was therefore designed to replace costly fishmeal (FM) with low-priced fermented fish silage (FFS) in fish feed. Fermented fish silage was prepared by fermentation process using Lacto bacillus bacteria and its fatty acid profile and effect on digestive system of Labeo rohita was investigated. Lipid contents were isolated by Soxhlet apparatus and recorded as 6.23 ± 1.23 g/100g of fermented fish silage (FFS). Fatty acid profile of extracted Lipids was determined by gas liquid chromatography (GLC), sufficient amount of unsaturated fatty acids were found with pattern mono unsaturated fatty acids (MUFA) > saturated fatty acids (SFA) >poly unsaturated fatty acids (PUFA). Three treatment diets containing 100% silage (T1), 75% silage (T2) and 50% silage (T3) were prepared by mixing it with soybean meal (SBM) and rice bran as co-ingredients while fermented fish silage was replaced by fishmeal in control diet (T0). The experiment was conducted in glass aquaria in triplicate. Fish growth parameters were recorded fortnightly while physico-chemical parameters of water were recorded on daily basis. After completion of feeding trial, three fish were randomly dissected to excise out their intestines and determine activity for protease, amylase and lipase enzymes. Non-significant differences (P<0.05) were recorded in growth parameters and enzymatic activity among all diets except lipase enzyme. Deceptively, it can be concluded that FFS has reasonable concentration of nutrients and unsaturated fatty acids so it can successfully replace fishmeal in fish diets.