Cover per cow needs close attention

Growth has been somewhat stifled on farms this week with some very wet weather in places last weekend and slightly lower temperatures.

There is a cohort of farms with ground closed off for reseeding and a lot of area taken out for silage that are starting to feel a bit of pressure. Cover per cow is dropping under 170kg DM and subdued growth rates have meant little surpluses.

For these farms it may be worth grazing one or two of the heavier covers that have been marked for surplus bales to give a bit of wriggle room until growth lifts. It’s worth noting these farms are in the minority and the majority of farms according to Pasturebase have a lot of grass. Average cover per cow is closer to 200kg DM and higher in many cases.

Grass quality will be the worry for these farms as there will be a lot of surpluses on the horizon. If cows are going into heavier covers now, they won’t be able clean the paddock off well enough. The grass plants left behind will become stemmy and high in fibre as they grow back.

This stemmy grass is a poorer-quality feed and cow’s milk production will suffer. The only solution will be topping or mowing in subsequent rotations. To stay ahead of these issues, target grazing paddocks at 1,300-1,400kg DM/ha. If covers are getting too far above this, it’s best advised to take them out as surplus bales and correct the grass wedge.

Drop meal feeding levels and increase stocking rate by closing paddocks where there are surpluses. For example, on a farm growing 70kg DM/ha and where cows are eating 17kg/DM grass per day, the platform would need to be stocked at 4.1 cows/ha to match demand.

Fertiliser

All farms should have 80 units/acre of nitrogen out by now. From now on, cows should be followed with 18 to 20 units/nitrogen per round. Sulphur is also very important at this time of year.

On farms where clover is sown, it seems to be starting to take off. From mid-May on paddocks with good clover will need to have nitrogen levels cut back to half-rate.

Johnstown Castle, Wexford

We’ve 40% of the farm cut for silage over the last couple of weeks. This ground hadn’t been grazed with the wet spring and it yielded 4.8t DM/ha. Some of that ground will start coming back into the rotation and stocking rate will fall back to 4.2 cows/ha. Demand is 76kg DM/ha for the autumn herd now so we’re in a comfortable position with grass. Grazing conditions have been excellent in recent weeks despite 12mm of rain over the weekend.

Lifford, Co Donegal

We made 42 acres of first cut silage this week, which included five acres of surpluses from the platform. Cover per cow is in a good place but growth rates are predicted to be back this week with colder weather by night. We’re following cows with 22 units/acre of protected urea plus sulphur. Breeding started on 4 May here and we’re planning to use 50 sexed straws. The 28 heifers will get one each if the timing is right and the rest will be used on cows.

Hospital, Co Limerick

We took two paddocks out that hadn’t been grazed in the first round and another two that had covers over 1,600kg DM/ha last Wednesday. These will be coming back into the rotation shortly. There is another ten acres that was reseeded last week also. We had a lot of rain over the weekend but cows stayed out. Demand is 60kg DM/ha and we plan to hold it here. Breeding on the cows is starting Saturday and over 50% of the heifers are bred already.