11 February 2000

Right stocking for top yield

Principles of successful New

Zealand dairy management

and applying them for profit

were key topics for west

Wales Grazing Dragons on a

Welsh Development Agency-

funded trip to a conference

and farms in Ireland.

Jessica Buss reports

PRODUCING top yields from each hectare of grazed grass requires a high stocking rate and the right type of cow.

On a visit to his farm at Rath-peacon, Co Cork, milk producer Michael Murphy told the Welsh Development Agency-funded Grazing Dragons that he stocked his 170 cows at 3.35LU/ha (1.36/acre).

He believes this is the best way to maintain a tight grazing policy, with cows going out to graze day and night from calving in spring.

Concentrate use is budgeted at just 70kg a cow a year, but more is fed in a dry summer – last year it totalled 275kg a cow.

"We plan to feed 3kg of meal in spring until our grass budget balances, usually in mid to late March."

But the stocking rate is lower than in 1995 when cows were stocked at 3.6/ha (1.46/acre), before the herd was culled due to Brucellosis. Between 1980 and 1995 the herd produced 19,500 litres/ha (7890 litres/acre). But since replacing the herd, production has not risen to the same level a hectare and that has cut profits, he said. Last year cows averaged 4900 litres, producing 15,200 litres/ha (6150 litres/acre)

"With the old herd, we only lost 2-3% cows which were empty a year, had a 90% submission rate and 60% conception rate. On our other farms we still aim to calve half the herd in 10-11 days. But when the herd was replaced the type of cows we wanted were not available. We now have high index Holstein Friesians that are being New Zealandised. But we had 13% empty in the first year and 9% last year, we also have 20 cows calving in April, which is too late.

"Half the herd are bigger and less suited to a hard grazing system. They are slower to get in calf and we have to watch their condition score."

He believes that fertility will improve over the next few years as the type of cow becomes more uniform. But he also plans to continue using high survivability NZ bulls with reasonable genetics whose progeny will get back in calf. His aim is for medium sized cows with reasonable capacity and good fertility.

Besides the right cow type, another key factor in maintaining a high stocking rate is managing condition score. Cows due to start calving in early February have been fed silage since housing on Dec 8 and average condition score three.

"Heifers have had concentrate until recently and if dry cows are thin we will feed them meal. Thin cows and heifers are also dried off early so they have 11-12 weeks dry in order to improve body condition."

But he believes it is possible to keep cows in adequate condition at such a high stocking rate on a rotational grazing system, without relying on bought in forage. "We rarely have to buy silage for winter – possibly one year in five."

But high stocking rates make it vital to monitor grass available, by measuring grass DM, and predicting growth through experience and soil temperature testing. In March he measures grass and soil temperature every five days and adjusts his grazing plan accordingly.

"When cover falls under target at a high stocking rate it is difficult to get it up again. We also have to be more disciplined about building cover in spring because demand is low initially. In autumn, when grass cover gets down to a certain level cows come in."

Producing high yields of milk a hectare requires a high stocking rate, says Michael Murphy (inset). Cows will go out day and night after calving.

HIGH STOCKING RATE

&#8226 Requires fertile cows.

&#8226 Measure grass frequently.

&#8226 Plan grazing.