How much nitrogen does a dairy cow or a buffalo excrete in a year according to the Intergovernmental Panel on Climate Change defaults?
Equation 10.30 multiplies the daily rate per 1,000 kilograms (kg) of animal by typical animal mass divided by 1,000, then by 365. With the Asia defaults of 0.47 for dairy cattle and 0.32 for buffalo, and Indian Subcontinent masses of 275 and 295 kg, a cow excretes about 47 kg of nitrogen a year and a buffalo about 34 kg.
The equation and the defaults
- Equation 10.30 of the Intergovernmental Panel on Climate Change (IPCC) 2006 Guidelines, Volume 4: annual nitrogen excreted = daily rate per 1,000 kg of animal mass x typical animal mass / 1,000 x 365.
- Table 10.19 has a column per region, not one for India. The Asia column gives 0.47 kg of nitrogen per 1,000 kg of animal per day for dairy cattle, 0.34 for other cattle and 0.32 for buffalo.
- Typical animal masses come from Annex 10A.2. For the Indian Subcontinent it lists 275 kg for a dairy cow (Table 10A-4) and 295 kg for a buffalo (Table 10A-6).
- The guide gives an uncertainty of 50 per cent on the excretion rates.
Using your own animal weights
The guide says the rate can be applied to animals of different ages and growth stages using the typical mass of that group, and that country-specific masses are preferable because excretion is sensitive to weight. If you weigh or tape your animals, use those masses in the same equation.
The Tier 2 route from feed
Equation 10.31 works excretion out as daily nitrogen intake x (1 minus the fraction retained) x 365. The default retained fraction in Table 10.20 is 0.20 for dairy cows and 0.07 for buffalo and other cattle, again with a 50 per cent uncertainty. This needs feed intake and crude protein of the diet, which most small dairies do not have.
Dung cakes: only part of the nitrogen is burned
For manure managed as burned for fuel, the guide says the dung is burned and the urine stays in the field, and as a rule of thumb 50% of the nitrogen excreted is in the dung and 50% in the urine. Do not treat the whole excretion as burned.
Per animal and for 100 dairy cows
- Dairy cow: 0.47 x 275 / 1,000 x 365 = 47.2 kg nitrogen a year
- Buffalo: 0.32 x 295 / 1,000 x 365 = 34.5 kg nitrogen a year
- 100 dairy cows: 100 x 47.18 = 4,718 kg nitrogen a year
- If all the manure is burned for fuel: 4,718 x 0.5 = 2,359 kg nitrogen in the dung and 2,359 kg in the urine left on the field. At the default 51% burned: 4,718 x 0.51 x 0.5 = 1,203 kg in burned dung
The 100 cows are an example. The 50/50 split is the guide's rule of thumb. The answers on nitrous oxide from manure storage and on ammonia loss use the 4,718 kg.
What Senseible does here
Senseible reads fuel invoices and electricity bills into emission records, so diesel for tractors and pumps and power for the milking shed and chilling tank show up once uploaded. The herd, manure and field figures on this page come from your own farm records.
- Nitrous oxide from manure storage
- Ammonia loss from manure and indirect nitrous oxide
- Dairy member farm emissions
Last reviewed 2026-11-05. Rates are 2006 regional defaults, with a printed uncertainty of 50 per cent. Replace with your own animal weights and feed data where you have them.