Abstract:

This experiment aimed to investigate the synergistic effects of added maize steep liquor and lactic acid bacteria during fermentation on the nutritional composition， rumen fermentation characteristics， and in vitro degradability of maize stover. Maize stover was prepared with four different pretreatments based on dry matter： no pretreatment for the control treatment （CON）； 1.0×10¹¹ CFU·g^-1 lactic acid bacteria pretreatment for the CL treatment （CL）； 5% maize steep liquor pretreatment for the CC group （CC）； and a 5% CC+ lactic acid bacteria treatment （CCL）. Distilled water was added to the maize stover to adjust the moisture content to 65%， and each group had four replicates. The nutritional composition， in vitro rumen fermentation characteristics， and in vitro digestibility of the maize stover were analyzed after 56 days of anaerobic fermentation. Results showed that： 1） The crude protein and acetic acid contents in the CL， CC and CCL groups were significantly higher than in the CON group （P<0.001）， and the pH values in the CL and CCL groups were significantly lower than that in the CON group （P<0.05）. 2） Compared with the CON group， the in vitro fermentation ammonia nitrogen concentration in the CL， CC and CCL groups was significantly increased （P<0.05）， the acetic acid and the total volatile fatty acid concentration in the CCL group was significantly increased （P<0.05）. 3） Compared with the CON group， the in vitro dry matter degradability in the CL， CC and CCL groups were significantly higher than that in the CON group （P<0.001）， and the in vitro crude protein degradability in the CC and CCL groups were significantly higher than in the CON group （P<0.05）. In conclusion， the addition of synergistic fermentation of maize steep liquor and lactic acid bacteria enhanced the nutritional value of maize stover， improved its fermentation quality， and increased the degradability of nutrients.

Key words: corn stover, corn steep liquor, nutritional composition, in vitro degradability