Assess feed options for best price
Published 09/03/2010 | 05:00
It looks like grass growth is three or four weeks behind normal. In fact, there has been no growth since the end of November.
However, since we are getting further into the spring I would expect that when mild conditions come, there will be a good growth response and we will catch up in two or three weeks.
Still, there is no sign of a change yet and even if milder weather came now, it will be late March before there will be grass available. Soil temperatures are only rising slowly and are still, except in coastal regions, 2°C below the growth threshold. Last week I said to hold off on spreading nitrogen as there would be no response and that remains the case while temperatures remain low. But you should at least have it in the yard and ready to go. As ground conditions remain good, and we get further into March, I would put out nitrogen on the grazing areas. Given current conditions there is no risk of leaching losses and a decreasing risk of other losses (such as de-nitrification) as the temperature comes closer to the growth threshold.
As grass growth is behind normal, it inevitably means that winter feeding has to be extended to make up the difference. In a year when winter feed supplies were already scarce, it adds to the difficulty. If you think you might be short of fodder, the first thing to do is to take stock of what is available.
When fodder is scarce the price will rise. At a farm walk in Galway last week, a price of €37/bale was quoted for silage. At prices like this there are cheaper alternatives. However, cattle need a minimum level of roughage to keep the rumen functioning. If you have this minimum level, which is about 40pc of daily intake, you can stretch it out and substitute concentrates for the other 60pc. If you have more than the minimum level but are still a bit scarce, then you can feed relatively more silage and less concentrates. As a rough guide, every kilogramme of concentrates you feed will save 7kg of fresh, moderate-quality silage.
Table 1 (right) shows the amount of meal needed with minimum roughage to maintain condition on cows and to provide a liveweight gain of about 0.3kg/day on weanlings and store cattle.
If straw is the roughage source, feed ad-lib, increase the meal rate by 30pc and the crude protein in the ration to 18pc.
A cow will eat about 45kg of silage a day, so 18kg is 40pc of normal intake. Where you were feeding to ad-lib silage intake, you can cut back to less than half that amount and substitute with meal. Do so gradually. If cows are getting no meal, start with about 2kg/day and increase by 1kg every four days until you reach the required amount. Some people worry that feeding 3kg meal to pregnant cows will lead to calving difficulty but there is no evidence that this is the case. The cow needs a certain level of energy and protein in late pregnancy and the type of energy supply is not an issue.