Dairy Event 2010: Sheep aid dairy grass growth
Tack sheep will improve spring grass quality on dairy farms that don’t turn out cows early, but if the flock stays beyond January grass yields can be compromised.
In Carmarthenshire, Lloyd Thomas runs a high-input, high-output dairying system and uses tack sheep to manage his spring grass quality.
With clay soil and a high rainfall average the farm isn’t suitable for grazing late into autumn. Additionally, the need for consistency in the diet of the high yielding Holstein Friesian cows means the herd is often housed completely by September.
In this situation the grass, if left unmanaged, would be stale and lack quality by the following spring. Mr Thomas says tack sheep are the ideal grass management tool, arriving in November and leaving by the end of January. “It gives us clean pastures and it improves grass tillering. When the grass is kept short the regrowth is thicker,” he says.
“The sheep nip any surplus growth or stale grass. A lot of farmers would call this next year’s growth, but for us the type of the farm we have doesn’t lend itself for early turnout. If we were in an early turnout area we wouldn’t have sheep in the winter.”
When the sheep, about 200 in number, arrive in the autumn they are allocated specific fields where grass is more abundant. In the four weeks before they depart they can roam the farm. “We like to manage the sheep during the short period they are here,” says Mr Thomas.
They are on the farm for up to 12 weeks. In previous years they remained until the beginning of March, but as cow numbers increased Mr Thomas could see they were robbing the herd of grass. “When the grass is growing in January we don’t want the sheep taking it,” he says. The tack sheep do generate an income, but this is seen as a bonus and not central to the reason for having them on the farm.
Plas Farm is a 101ha (250 acre) holding and Mr Thomas rents a further 80ha (200 acres). His all-year-round calving herd is milked three times a day and is averaging about 10,000 litres. Although TMR is integral to the system, Mr Thomas says grass is important, too. “We grow grass well from May to August and I like to graze cows for part of the year to take advantage of that,” he says.
If the spring is dry cows will go out to graze in May, but if it’s wet all the grass is cut as clamped silage. In this instance, the cows are housed until mid-June. But Mr Thomas doesn’t overlook the cost associated with cutting silage.
“It’s a matter of balancing the loss of production with what it is going to cost to make silage. Consistency is key in the cows’ diet, there can’t be too many variables otherwise we would see a dip in fertility and performance.”
During the grazing period they get a TMR ration of 26kg grass silage, 11kg whole-crop, 3kg bread waste, 6kg protein blend, 0.5kg straw, 0.5kg Megalac and 0.15kg minerals. The fresher cows are topped up to a maximum of 4kg of concentrates in the parlour.
When conditions permit, the cows graze for part of the day between May and August. They are turned out at 7am, after being milked, and come in again at 1pm. Mr Thomas is aiming for between 10 and 12 litres of milk from grass, but this does depend on dry matter. “When we get to the end of August there isn’t a great deal of value in the grass. We try to be as flexible as possible, but to keep milk in the tank we have to keep the cows happy,” he says.
He reseeds 8ha (20 acres) every year, but the tack sheep don’t have any impact on this. He says he reseeds to maintain grass quality. “Forage quality is most important, whether that’s in pasture or silage. The sheep are here during the winter period because the leys are relatively young and there is grass growth late in the season,” he says. “If left to their own devices the leys would have a lot of stale growth. We want it fresh and for it to have quality in it.”