Dairy: It's time to start catching up on the herd's grazing targets
Published 02/03/2016 | 02:30
The last time I wrote in this column four weeks ago, I spoke about getting cows and fertiliser out where possible. The reality is that this was just not possible, except for a small minority of farmers on extremely free draining soils. But now the clouds have finally lifted, we have some catching up to do.
Getting through the grass
Normally the target is to have a third of the farm grazed by March 1st, two thirds grazed by the middle of March and the first round finished in the first week of April. For most, we are definitely not going to get the third grazed by March 1st, the two thirds looks very challenging, but we may still be able to get the entire farm grazed by the first week of April.
If we take a farmer with 100 cows on 40ha who will on average have 80 cows calved in the month of March. These 80 cows will eat approximately 13kgs of grass dry matter (if conditions permit) along with 3kgs of concentrate.
If this farmer has an average farm cover of 1,000kgs dry matter per hectare on March 1 then it will take him 40 days to graze out this grass, which means finishing the first rotation on April 10.
This in essence means that if we have any chance of eating through the heavy covers on farms, then cows have to get two grazings per day.
This can be achieved by leaving cows out fully, if conditions permit, or by leaving them out fully by day and leaving them out for a further three hours after the evening milking.
Bring forward the evening milking to 4pm, leave the cows out straight after milking and bring them back in again at 8pm. Graze the third of the farm with the lowest covers first. At least then you will have one third of farm growing actively in time for the start of the second rotation.
Despite the good dry week we've had, heavy soils still have a bit of more soaking to do. In these situations, we have to target two sessions of grazing consisting of three hours each after both milkings, with minimal silage being fed at night.
Fertiliser spreading has increased significantly over the past week. The same targets apply, 70 units by April 1. If you have not already spread then you need to go with 40 units of urea straight away. This needs to be followed up with approximately 30 units four weeks later, ideally in the form of 1.5 bags/ac of 18.6.12, where Nitrates Regulations permit.
Farmers on heavier soils could delay these targets by two weeks. Not getting the 70 units out will lead to many farmers hitting a wall in mid April with regard to growth rates. Farmers who get the 70 units out will grow double the grass in April than those who don't.
Replacement heifers intended to calve down next spring, need to be greater than 330kgs at breeding. For many, the breeding of these heifers starts around April 20. This leaves 50 days for heifers to hit their target weight. Heifers at grass should easily gain 1kg liveweight per day. Any heifers under 280kgs need to get to grass straight away.
Lighter heifers (250-260kgs) still have a chance of being bred this May. They need to get to grass straight way, and will also need to be supplemented with 2kgs of a high energy ration for the next 60 days.
Breeding start date may need to be delayed by three weeks to give them sufficient time to hit the targets, but still allowing for them to calve in February 2017. Weigh your heifers and get them to grass as soon as possible.
Joe Kelleher is a Teagasc dairy advisor based in Newcastle West, Co Limerick