8 August 1997

HITTING HIGH MILK YIELDS WITH ROTATIONAL GRAZING

ROTATIONAL New Zealand-style grazing helps one Wilts producer achieve 5000 litres from forage, with 75% of this coming from grazed grass.

Jonathan Rider, Horton Farm, Devizes, speaking at the Genus Conference, explained that the 5900-litre herd was managed to make the most from grazed grass at a stocking rate of 2.5 cows/ha (1 cow/acre). The 400 cows had calved from January to March for cows to be freshly calved at turn-out, but Mr Rider plans to move calving a month later next year to increase grazed grass to over 80% of the cows total forage needs.

Every % increase in grazed grass could increase profit by 0.2p/litre, so a 15% increase could save 3p/litre, he claims.

Mr Rider estimates that moving the calving period would reduce concentrate use by 150kg/cow down to 500kg/cow and cut silage needed below the current 1.25t of dry matter a cow.

Silage is three times more expensive than grazed grass, claims Mr Rider who only cuts when there is a surplus of grass, usually in late May.

"This spring was ideal, and we made considerable savings by getting cows out early. Our winter ration of silage and concentrates cost £2 a cow, but from Mar 10 cows were out day and night reducing feed costs to 90p a cow. In late March, and early April, 75% of the cows ration is from grazed grass costing 55p a cow. At each of these stages milk increased by one litre a cow."

Paddocks have a cover of 2500kg DM/ha in spring and are grazed down to 1400kg DM/ha. The grazing rounds are typically 21 to 25 days – tending to be longer in spring and autumn.

Grass shortages in summer almost double our concentrate needs, he claims. To overcome this, he was considering increasing the irrigated area from 40ha (100 acres) to 80ha (200 acres) this summer. Irrigated pasture produces an extra 3300kg DM/ha of grass, he adds.

Well managed grass is extremely nutritious and is conducive to good cow health, improving fertility and reducing lameness and cell counts. It is also less complicated and more relaxed for all those involved with the cows, he says.

Forage turnips, lucerne and maize are also grown to supplement grass and grass silage. &#42

MAXIMUM GRAZING

&#8226 Calve early February.

&#8226 Turn out cows early.

&#8226 Keep concentrate use low.

&#8226 Measure grass available.

Good access and rotational grazing ensure maximum use of grass at Horton House Dairy, says Jonathan Rider.