Production Technology of Fermented Distiller’s Grains and Its Effect on Production Performance and Egg Quality of Laying Hens

The high acidity, alcohol, and mycotoxin levels in distiller’s grains (DGs) limit its application in practical production. To address these issues, a new DG fermentation technique was developed in this research. Firstly, four strains were selected and the fermentation conditions were optimized to ferment the fresh DGs. When the inoculum was set at 8%, the fermentation temperature was maintained at 35 °C, the fermentation time lasted for 48 h, the bacterial mixture ratio (Bacillus subtilis ASAG 216: Lactobacillus acidophilus G1: Saccharomyces cerevisiae ANP 101: Streptococcus thermophilus EFR 046) was 1:1:2:1, and the contents of crude protein in fermented DGs (FDGs) were the highest, so we chose these fermentation conditions to ferment the DGs. In addition, under these fermentation conditions, the amino acids were significantly (p < 0.05) increased while the concentrations of crude fiber and mycotoxins contents were significantly (p < 0.05) decreased in FDGs than in DGs. Subsequently, the nutritional value of DGs and FDGs were evaluated using a two-step in vitro digestion method. The digestibility of dry matter, protein, and crude fiber increased by 16.23%, 13.54%, and 64.09%, respectively, in FDGs compared to that in DGs. Finally, laying hens were treated by adding 0%, 1%, 2%, and 4% FDG to the basal diet for 4 weeks. The results demonstrated that addition of 2% FDG in the diet could significantly (p < 0.05) increase the laying rate of hens compared to that fed the control diet, while addition of 4% FDG in the diet could remarkably (p < 0.05) reduce the rate of broken eggs compared to the other groups. There were no significant (p > 0.05) differences in other indices. These indicates that FDG has potential as a functional feed additive to enhance animal productivity.