Effects of probiotics and bremelain fermented soybean meal replacing fish meal on growth performance, nutrient retention and carcass traits of broilers

This study investigated the feasibility of dietary supplemental mixed probiotics and bromelain fermented soybean meal (FS) and the strength of fermented soybean meal (SFS) (adjusted amino acids and protein) to replace expensive fish meal for broilers, in order to reduce feeding cost. Trial 1 investigated the effects of adding different levels of mixed probiotics fermented solution and bromelain (a kind of protease extracted from pineapple) on the quality of fermented soybean meal. Trial 2 included (1) 4% fish meal (FM) as the control, (2) 6% wet fermented soybean meal (WFS), (3) 5% soybean meal (SBM), (4) 5% wet strengthened fermented soybean meal (WSFS) and (5) 4.5% dry strengthened fermented soybean meal (DSFS) groups. The best outcome of Trial 1 resulted from inoculation with a 34% fermented solution and 0.05% bromelain, and incubation at 34±0.5 °C for a week. Results from Trial 2 showed that the growth performance in the FM group had a significantly better average body weight gain (BWG) and feed intake (P<0.05) compared to the SBM group. The relative spleen weight in the WFS, WSFS and DSFS groups was significantly higher than that in the SBM group (P<0.05). In conclusion, SBM replacement with FM has an adverse effect on growth performance; FS can improve this adverse effect. FS had no negative effects on the replacement of FM in the broiler diet, implying that with respect to economic issues, the FS has the potential to be used as a FM substitution.