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To allow for grazing into the autumn, it is vital to build grass covers during the month of August.
Similar to a lot of farms in the northeast, James King outside Ballymena in Co Antrim struggled with grass growth during the dry weather in July. While it has started to grow again, a grass walk last week put growth at only 16kg dry matter per hectare (DM/ha) per day over the previous 24-day period.
During the dry spell an additional 16 acres (6.5ha) of grazing was brought in and this has helped to extend the grazing round and lengthen the rest period between grazings. As a result, average farm cover is not far off target at 2,200kg DM/ha (around 700kg in Republic of Ireland system), with the aim to get this figure up towards 2,500kg DM/ha by the end of the month. Given that the farm is highly stocked, James needs to start building covers now, and target going into higher covers of up to 3,000kg DM/ha by 1 September.
Nitrogen (N) was stopped during the dry spell, but with the recent rain the plan is to get 27 units per acre (one 50kg bag per acre) on behind the cows and any fields that have been missed during the dry weather.
However, N is easily lost, and spreading when heavy rain is forecast within the next three to four days should be avoided. With more settled weather ahead, there is the opportunity to get N on over the next few days.
The grazing block on the King farm is already at the optimum for both phosphorus (P) and potassium (K), so CAN is being used.
Cows in milk
James will also begin calving at the end of September, so the first cows have been dried off, which is also helping to take some pressure off demand.
At the end of July, 152 cows were in milk averaging 24.2l, on an average of 5.2kg concentrate per day.
During the dry weather, buffer-fed round bale silage was introduced around milking times, with cows eating approximately 4kg - 5kg DM per head per day.
The plan is to keep the buffer in the diet for now, to help build grass covers.
Measure grass
According to Dairylink CAFRE adviser Kathryn George, the decision to either reduce the buffer feed, or take it out entirely, will ultimately depend on how much grass is being grown, and how much is available to the cows.
“You need to measure grass to see what is in front of them. It is pure guesswork if you don’t. To build covers in August you need growth to be about 15kg DM/ha ahead of demand,” she said.
Kathryn estimates that cows will eat approximately 14kg to 15kg grass DM per day if grassland management is good. At best, that intake would be capable of sustaining maintenance plus 16l. In other situations, maintenance plus 12l to 13l might be more realistic.
Ultimately, final feed setting will depend on grass availability and grazing conditions on the farm
As we move on into August, Kathryn advises that anyone working at maintenance plus 16l should reduce this by at least 2l per cow per day.
Feed settings for first lactation animals should be set at a maximum of 13l, reducing to maintenance plus 10l to 11l as we move through the month.
“Ultimately, final feed setting will depend on grass availability and grazing conditions on the farm,” said Kathryn.
Cows being dried off ahead of autumn calving
With autumn calving due to begin at the end of September, a total of 28 cows have been dried off by James over July, with a further 10 dried off in the first week of August.
The herd is split autumn and winter calving, so there will still be milking cows to graze on the farm well into October if conditions allow.
The dry cows have been moved to an out-farm and are currently grazing what is effectively a crop of standing hay
The aim at drying off is to have cows in a condition score of 3, and give cows an eight-week dry period.
They were dosed for fluke and worms, received a mineral bolus and were treated for flies.
The dry cows have been moved to an out-farm and are currently grazing what is effectively a crop of standing hay.
They will be housed around three weeks pre-calving and move on to a transition diet.
The silage in the diet was specifically grown for dry cows to be low in potash (K). It received no slurry or compound fertiliser.
Once calved, cows will be kept inside and move over to a milking cow diet.
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