30 November 2001

Reseeding leys prolongs grass season

RESEEDING of grazing and silage leys with new grass/clover varieties has allowed three college dairy farms to cut silage costs and extend the grazing season.

Results from several Practice into Profit demonstration farms – Gelli Aur, Duchy College and Newton-Rigg – were presented at the conference. These colleges are developing their use of grassland to improve farm profitability.

Some silage fields were reseeded, at a rate of 16.5kg/ha, with a mixture of 70% new hybrid ryegrass, 25% intermediate perennial ryegrass and 5% white clover.

Over a three-year period, the average dry matter yield of new leys showed a 41% improvement on overall farm silage yields – 6.17t DM/ha compared with 4.37t DM/ha.

"Part of this increase in yield resulted from the hybrid ryegrass exceptional early growth and high yields," said Gwyn Moseley, leader of the Practice into Profit project.

The new ley yields easily met Gelli Aurs silage requirements of 566t/year, with two rather than three cuts, reducing overall silage costs from about £82/t to £60/t, he added.

And reseeding of some grazing leys resulted in an average 32% improvement in grass production during the main growing season – Apr 1 to Oct 31. The seed mixture used was 30% hybrid ryegrass, 30% intermediate perennial ryegrass, 30% later perennial ryegrass and 10% large and medium leaf white clover.

New leys produced about 13.8t DM/ha a year compared with 10.5t/DM/ha for old leys. "The new leys, combined with careful grazing, gave a more even spread of growth throughout the season. This increased the number of part and full days extra spring grazing, with southern farms turning out up to two months early," explained Mr Moseley.

Gelli Aurs extra 62 spring grazing days improved profits by 56p/cow a day because of reduced silage intake and housing costs and in early season, a small increase in milk yield.

The inclusion of clover in the grazing sward also increased profitability, he added. "Clover bulked out mid-season grazing, reducing the need for buffer feeding and concentrates.

"Compared with grass-only pasture, the clover/grass mix yielded 13.5% higher growth rates during the drier, summer months. For a 100-cow herd, savings in supplementary feeds amounted to £51.30/day, or £4720 over three summer months." &#42

New silage leys can yield up to 41% more dry matter yield than old leys, said Gwyn Moseley.