Dietary nitrogen - definitions, digestion, excretion and consequences of excess for grazing ruminants

New Zealand pastures often contain a higher concentration of nitrogen (N) than required by ruminants, and this can be exacerbated by application of N fertilisers to boost pasture growth. Excess dietary nitrogen (N) has negative implications for environmental sustainability and animal production, but producers and rural professionals are sometimes unaware of these issues and especially the terminology often used to describe the forms and fate of N. Keywords: nitrogen, ruminant nutrition, protein metabolism