19 August 1997

Profits lifted from autumn grazed grass

How are farmers in Ireland and England managing grass to lift profits? Sue Rider reports from last weeks FW/BGS grazing conference

THE BIG lie in English dairying is that autumn grass is a low value feed, claims Irish dairy farmer Michael Murphy, who milks 1200 cows and makes 16-17p/litre profits.

"When well managed it is a better quality feed than the best quality silage," he told the conference, held at JG Quicke and Partners, Newton St Cyres, Devon. Grass samples from his farm taken last November by Moorepark, Irelands dairy research centre, averaged over 12 ME, or 80 D value.

"We regularly expect herd performance of 28 litres – cows and heifers – from autumn grass plus 4kg of concentrates," said Mr Murphy. That was a bulk tank average over two to three months.

But to achieve such performance off grass from autumn calved cows, management was critical.

He feeds no silage until Nov 20; until then cows are on 4kg of concentrate – fed as two feeds – and go into paddocks with grass covers of about 3500-3700kg/ha DM. Swards are no longer than that, otherwise quality would fall, he said, and grass is also likely to be leafy as a result of consistent grazing pressure on the previous rotations. If cows graze down to 1500-1600kg, there is no winter kill once the paddock is closed, he said.

Grazing is managed as 12-hour blocks rather than strips. Paddocks should be as square as possible. "Cows do more poaching on a racecourse type block than a square one," he said. Even in good conditions block grazing increases grass production by 27% compared with strip grazing.

"After grazing, the ryegrass quickly puts up a new shoot to regrow. When that is grazed off early on root reserves are depleted and the grass will then sit there for months on end doing nothing."

There should be good farm roads – well crowned to allow run off – with access to all paddocks and two or more entrances to most paddocks. Entrances must be well grassed to prevent mud being pulled into the field, he said.

Go hungry

If it is wet he suggested allowing the cows out for only two to three hours grazing. "Ensure cows go out hungry. Only give them enough concentrates and silage so they have finished feeding by midnight."

Cows also do less damage if they graze the backs of paddocks first. "This ensures they have a raft of grass underneath them to keep them up and reduce poaching." On day one, for example, he would walk cows to block one over block two (see diagram). He then puts up a back fence, so when cows graze block two they cant go into block one. To access block three, cows walk over block four.

The key is to be flexible and adjust grazing times to grass conditions, he said.n