Solid state fermentation of palm kernel cake and brewers' spent grain elevates amino acid profile and proximate compositions of aqua-feed and feed amino acid fluxes

High cost of aqua-feed production translates to low profitability and high cost of production of fish. There is need to utilize low cost agro-wastes feed ingredients in aqua-feed production. Palm kernel cake (PKC) and brewers' spent grain (BSG), are plausible proteinous fishmeal alternatives and agro-industrial feed ingredients. However PKC and BSG contain high fiber and anti-nutritional factors (ANFs) that limit their usage and fed ingredient value. Solid state fermentation can remove this ANFs, degrade high fibers and elevate the protein and amino acid contents of PKC and BSG. The species, Saccharomyces cerevisiae was used in the fermentation of PKC and BSG. Thereafter, the fermented feed stuff were incorporated at varying levels: Feed 1 (40:0), Feed 2 (30:10), Feed 3 (20:20), Feed 4 (10:30) and Feed 5 (0:40) for PKC : BSG respectively to formulated the different experimental diets. The formulated diets were then analyzed for proximate and amino acid compositions following standard procedure. Results showed that fermentation processes reduced fiber content of PKC and BSG from 21.78±0.01% to 12.54±0.01% and from 26.75±0.07% to 18.74±0.01% respectively while increasing protein content of PKC and BSG from 19.24±0.01% to 22.89±0.01% and from 23.84±0.71% to 26.32±0.03% respectively. This may indicate that solid state fermentation can significantly improve the nutritional profile of PKC and BSG. Solid state fermentation enhanced the essential amino acid profile, with notable increases in amino acid contents.