Many farmers have been enjoying the dry conditions early this spring, which has allowed a smooth spring grazing for the most part so far this year.
However, with rain forecast in the coming week, conditions may get a bit tougher, which could result in grass allocations becoming harder to manage.
Many farmers have started grazing their lightest covers in early spring, that is, the covers of about 400-600kg dry matter (DM)/ha, but farmers should also start to graze the cover of 700-1,000kg DM/ha.
With conditions forecast to get a bit more challenging, farmers should aim for at least one grazing a day, as even a three-hour allocation could be hugely beneficial.
Being out and about on farms this spring, some farmers have been restricting their cows’ access to silage after morning milking, which allows them to build up an appetite by 10:00am to go out grazing.
Another farmer I was out with had gotten his silage allocation exactly right in the evening time, ensuring there was no silage left over by morning, which made the cows eager to go out straight after milking.
Spring grazing
It can depend on how long your cows have calved and the dietary requirements of your herd, but cows should be allocated roughly 6-7kg DM of grass by day, and this should be increased twice weekly if clean outs are good.
When conditions get a bit poorer, grazing methods, such as the set-up of back fences, spur roadways, and multiple access points to paddocks, should be implemented to try and get enough grazing without poaching and destroying the ground.
While it is good practice to get cows out grazing once daily and will be hugely beneficial in terms of milk solids returns and cost saving, a big effort should be made to avoid poaching and mucking up paddocks.
To avoid this, getting the grass allocation right through trial and error will help reduce this damage in paddocks.
Not only that, but it will ensure that cows are going out grazing and achieving good residuals and not leaving grass behind.
The grazing calculator on PastureBase Ireland is a useful tool at this time of the year, but it needs to be used while also going out into the paddock after grazing and seeing how cows performed.
To get the grazing allocation in February, a farmer needs to calculate the number of cows by the allocation of grass, e.g. 40 cows x 6kg DM = 240kg DM.
If we say that the paddock is 1.2ha with a grass cover of 1000kg DM/ha, that would leave 1,200kg DM available in the paddock (1.2ha x 1,000kg DM/ha).
If you take 1,200 and divide it by 240kg DM, it will give you five grazings, and 1.2ha split into five grazings will give you an allocation 0.25ha/grazing or 2,500m2.
If that paddock is 40m wide, divide 40m into 2,500m2 and you will get 62m. This means that in this paddock, you have to step out 62m in order to allocate the cows an appropriate amount of grass.
Again, don’t take this calculation as a certainty as the cow’s demand will change every day and each grazing will have to analysed and a decision made whether the cows need more or less grass.
