Lactic acid bacteria species naturally present in fish (Streptococcus spp., Lactobacillus brevis, Lactobacillus plantarum, Pediococcus acidilactici and Enterococcus gallinarum) and formic acid were compared for production of fish silage, which are protein hydrolysates with immune stimulating properties. It is the first report for Enterococcus gallinarum to be used for producing fermented products. In this study, chemical and microbiological qualities of fish silage by acid or fermented methods were assessed after ripening of silages. It was observed that ripening was completed in maximum two weeks for all silage groups. Then, acid and fermented fish silage were spray dried and analysed for chemical and nutritional properties. As results of the study, these bacteria can be used as starter cultures in fermented products, especially for fish silage. In respect to essential/nonessential amino acid ratio (E/NE), the best groups among the spray-dried fish silages were prepared with formic acid, Lb. plantarum and Pd. acidilactici, respectively. Total antioxidant activity (TAO) of spray-dried fish silage was compared with ascorbic acid and TAO of spray-dried fish silages was found in range of 1.92-2.86 mg AA/g. The highest DPPH (diphenylpicrylhydrazyl) radical-scavenging ability of spray-dried fish silages was detected in AC group produced with Pediococcus acidilactici (20.26%) and GL group produced with Enterococcus gallinarum (16.95%), but there were no significant differences observed in other groups. According to the in-vitro gas production assessment, spray-dried fish silages generally had considerably high rate of digestibility. It was determined that the acid and fermented fish silage powders had high digestibility and valuable feed sources according to the results of the proximate analysis, amino acids compositions, total antioxidants, DPPH inhibition rates and in-vitro digestibility assessments.