Mr. Bill Callanan:

The excretion figure for a dairy cow is calculated using intake and offtake in terms of how much the animal is taking in. Nitrogen is looked at as being a basic block of protein. As the cow's output increases, her nutrient excretion increases as well. That is what generates 85 kg to 89 kg of nitrogen. Effectively, if we were to use a single figure for all cows it would be 91 kg to 92 kg of nitrogen today, rather than 84 kg of nitrogen when the nitrates came in in 2006.

The easiest way to describe this is when quotas came in in this country there were 1.5 million dairy cows who were producing 5.5 billion litres of milk. Some 20 years later that was actually produced by 1.1 million dairy cows, illustrating the growth in output and production of those cows. Compared to other European countries, Ireland's dairy system is quite a low output one. We average 5,000 l to 6,000 l whereas the indoor systems are 8,000 l or 10,000 l.

The excretion figure would have increased to that average figure in any event. The Commission required us to disaggregate between high, medium and low output dairy cows. I can assure the Senator that if he combined the numbers related to those three categories he would come back to the same average, which would be 91 l or 92 l - I do not know the exact figure. That is now simply translated into 80 kg for a low output cow, so those cows have seen their nitrate excretion figure go from-----