We are unaware of any reports in which eCH4
emissions of high-producing dairy cows fed different concentrations of CNO have been characterized. Our objective
was to identify a dietary CNO concentration for highproducing dairy cows at which the combination of eCH4
emissions, energy intake, NDF digestibility, and SCMY
are optimized. We hypothesized that moderate CNO
concentration will reduce eCH4
emissions while maintaining intake, NDF digestibility, and SCMY, whereas
greater dietary concentrations of CNO will depress
intake, NDF digestibility, and SCMY.