The study examined two theoretical approaches for improving nitrogen use efficiency (NUE) in dairy cows to reduce associated nitrous oxide emissions for three dairying regions of south-eastern Australia:
Treatments covered four supplementary feed N concentrations combined with four milk N concentrations.
The results showed that both options can improve NUE and reduced nitrous oxide emissions, though significantly greater abatement in nitrous oxide emissions can be achieved by improving animal NUE via reductions in the amount of N in supplementary feed, as opposed to increasing N exported in milk.
Christie KM, Rawnsley RP, Harrison MT, Eckard RJ (2013). Using a modelling approach to evaluate two options for improving animal nitrogen use efficiency and reducing nitrous oxide emissions on dairy farms in southern Australia. Animal Production Science, 54, 1960-1970, http://dx.doi.org/10.1071/AN14436.