Download A review of unpublished New Zealand trials examining diurnal variation and diet effects on faecal and urinary nitrogen concentrations in dairy cattle

Farmed animals in New Zealand contribute around 46% of the country’s greenhouse gas output. Of this, approximately 69% is methane (CH4) and 31% is nitrous oxide (N2O), with 80% of the latter resulting from nitrification and denitrification of urinary nitrogen by soil microorganisms and, to a much lesser extent, faecal nitrogen. To date, models evaluating the nitrogen (N) excretion of ruminants have assumed that N excreted in urine is constant and research on mitigating N2O output has largely focussed on nitrification inhibitors such as dicyandiamide (DCD), stand-off pads to keep stock off pastures in wet conditions and feeding low N feeds such as maize silage.