21 July 1995

Cows know what they like

Allowing cows to choose which grass varieties they prefer ensures an annual 4000 litres a cow from grazed grass alone for one Wilts dairy farmer

CHESHIRE-based co-op Deeside Dairy Farmers puts together grass seed mixes to meet the specific needs of its 30 farmer members.

Its four basic seed mixtures are updated every two years and clover content can be varied in three of them.

Before new varieties are included in either the short-term cutting or long-term grazing mixtures, they are tested on farms to see how well cows like them. "My cows will let me know which varieties they prefer," says Wiltshire dairy farmer Jerry Rider, who designs the co-ops grass mixtures. For someone who seeks 4000 litres a cow a year from grazed grass alone, sward palatability is vital.

"The late-heading perennial Profit is said to be highly palatable in mid-season but that has not been the case on our farm," says Mr Rider. He favours the tetraploid Condesa for its good mid- and late-season production. "It is one of the grasses most liked by the cows on the farm."

Mr Rider is convinced dairy producers dismiss the potential of grass because they fail to manage it properly. "It is the cheapest feed available for cows, and those seeking efficient milk production must learn how to manage it."

Good grass management starts with choosing the right grass varieties. Those in the short-term DDF number one mixture boast high levels of soluble carbohydrate for silage production. The high D-value Italian ryegrass Tribune offers high yields, despite suspect winter hardiness. But Trajan is a high yielding Italian with good disease resistance. The perennial ryegrasses that complete the mixture offer similar heading dates for an early bite or cut, and give a balance of winter hardiness and disease resistance, says Mr Rider.

He advises an August or September establishment to give the Italians in the mix a good start. Or, by sowing grass in early October after maize it would be possible to take a grazing between maize crops. Better still would be to graze and silage for a year before sowing maize the following April.

DDF number two is a three- to four-year, mainly cutting ley that can also be grazed. It comprises the New Zealand early perennial Yatsyn 1 for its high yields and early spring growth, although it does have low mid-season digestibility.

Other early perennial ryegrasses in the mixture are Moy, said to give high yields, spring growth, and ground cover, and Bastion for its winter hardiness and disease resistance. Tetraploids Rosalin and Merlinda offer palatability, but their high water content makes them trickier to silage. Merlinda also has low mid-season D value.

The medium-leaved clover Donna, which boasts high yields and good spring growth, can be sown alongside these perennial grasses.

Most popular DDF mixture is the long-term number three, updated with newer varieties to give good early mid-season growth. It includes Condesa for its high yields, good mid- and late season growth and winter hardiness; Tivoli for its yield, good mid-season digestibility and disease resistance; and Rosalin and Merlinda. Portstewart gives high yields and good mid-season digestibility as does Gilford which also offers good ground cover and early spring growth. Menna white clover is included for its resistance under hard grazing.

DDF number four is a new mix designed for mid-season and late production, and with extra clover would suit a no nitrogen regime, says Mr Rider.

The aggressive Merlinda has been dropped for fear it could shade out clover. The ley includes Condesa, Portstewart and Tivoli, as with number three, but adds Jumbo, for its good late production and disease resistance, and Fennema for its high mid-season D-value. White clover varieties are Menna and Donna to boost intake.

After variety, establishment is vital to give the ley a fighting chance in its seeding year, says Mr Rider. A firm seed-bed is essential. He believes the Moore Uni-drill guarantees better establishment than broadcasting.

After drilling it is important to roll well to get a firm consolidation. Once the crop is well established he lets the cows in to graze it. &#42

Picking their way… Cows graze this short-term DDF number one Italian ryegrass mix for the second time. They also had one silage cut.

Nice deep growth after a second grazing from this March-sown DDF number four mixture. The first grazing was six weeks after sowing to encourage tillering.