Crude protein: At the online Teagasc dairy conference on Tuesday the importance of reducing the crude protein content in dairy rations was highlighted by Laurence Shalloo. He said the recent change in the organic nitrogen per cow figure from 85kg to 89kg was linked to milk production and the amount of protein the cow is consuming. A 1% reduction in crude protein of dairy concentrates reduces nitrogen excretion by 1.6kg, according to Shalloo. The Teagasc advice is to feed concentrates with a crude protein content of 12% to 14% when cows are at grass.
At this time of year, and with cows housed, the crude protein content of the rations will have to be higher. It won’t make much difference to cows that are in late lactation as their milk yield is low anyway. It is more important for freshly calved cows or cows at peak production in winter and liquid milk herds. How much protein is required in the ration is dependent on how much protein is in the forage and you need a forage analysis to tell you this. The overall level of protein in the diet should be around 15% to 17%. Typical crude protein level in silage is between 13% and 17%.