This process enables the removal of excess H2 from the rumen and allows NADH to be reconstituted to NAD+, a process essential to the continuation of anaerobic rumen fermentation and microbial growth (Wolin, 1975).
Anaerobic nitrate reduction is energetically more favorable than CO2 reduction, and the presence of nitrate in the rumen redirects H2 from methanogenesis to nitrate reduction, thereby decreasing methane production (Allison and Reddy, 1984).