Effect of rumen liquid and <i>Bacillus</i> sp. on improving the quality of fish feed, using the predigested system

Abstract The main objective of this research is to improve the nutritional content of fish feed with a predigest system. The predigest system involved microorganisms consisting of rumen fluid and Bacillus sp. The research was conducted in vitro using a completely randomized design method with a factorial pattern. Two main factors were the dose of mixed microorganisms (0, 3, and 4.5mL/100g) and the length of incubation time (15, 30, and 45 minutes). The results showed that pre-digestion of fish feed with a dose of 4.5 mL/100g of mixed microorganisms with an incubation time of 15 minutes significantly affected (P&lt;0.05); there was an interaction between the two. There was an improvement in protein levels, nitrogen free extract, dry matter digestibility and organic matter. On the other hand, there is a reduction in the levels of crude fibre and ash. Research conclusion: A dose of 4.5mL/100g and a fermentation time of 15 minutes produced high nutritional value and was recommended as a raw material for feeding fish.