Development of highly digestible animal feed from lignocellulosic biomass Part 2: Oxidative lime pretreatment (OLP) and shock treatment of corn stover(1)

Oxidative lime pretreatment (OLP) increases lignocellulose digestibility by removing lignin and hemicellulose acetyl content. Digestibility is improved further by adding mechanical shock treatment, which subjects aqueous slurry of biomass to an explosive pressure pulse. Shock treatment mechanically disrupts the microscopic structure while maintaining the macroscopic integrity of the biomass particle. This study determined the effectiveness of these pretreatments to enhance the ruminant digestibility of corn stover. In terms of compositional changes, OLP and shock treatment should negatively affect the feed value of corn stover; however, digestibility analysis provides a significantly different conclusion. With corn stover, shock + OLP improved the 48-h neutral detergent fiber digestibility (NDFD) to 79.0 g neutral detergent fiber (NDF) digested/100 g NDF fed, compared to 49.3 for raw corn stover. The 48-h in vitro total digestible nutrients (TDNom, g nutrients digested/100 g OM) was 51.9 (raw), 59.7 (OLP), and 72.6 (shock + OLP). Adding extracted corn stover solubles to shock + OLP increased TDNom to 74.9. When enough solubilized chicken feathers were added to match the protein content of corn grain, TDNom increases to 75.5, which is only 12.6 less than corn grain.