26 February 1999


Is there a right way to manage high genetic merit cows? That is what a session at the British

Cattle Breeders Club aimed to find out. Jessica Buss reports on the two options considered

EXPLOITING grass and breeding cows with high genetic merit has allowed one Irish producer to increase production to 8400kg from just over a tonne of concentrate.

Donal Cashman told the conference that his top 10 spring calvers achieved yields of 9750kg from just 700kg of concentrate.

All spring calvers are flat-rate fed concentrates until mid-June and average 8863kg of milk. Autumn calving cows are flat-rate fed 1.5t of concentrate and average 8352kg.

He said many Irish milk producers calved only in spring, but as his farm was near Cork city he supplied liquid milk and hence calves 60% of his cows in autumn.

Quota is linked to land in Ireland and there is a heavy clawback on any sales, making increasing quota inflexible and difficult. Mr Cashman, therefore, has to produce within his quota of 1,061,658 litres.

His 100ha (250-acre) Coole Farm, is in a high rainfall area, with an average of 1050mm (42in) a year, so grass is used heavily.

Adequate grazing

The farm is divided into 38 paddocks, each with two entry points from the farm roadway and with access to the next paddock at the bottom, making it easier to ensure adequate grazing is supplied for each feed.

"Normally, cows go out by day in early March and night and day in late March. They are housed by night in late October and full time by mid-December. They spend 30 weeks full time on grass and only 12 weeks fully housed."

Rotation length is maintained at 23-27 days during the main grazing season, with cows following calves and older heifers following cows from May to October.

To ensure high-quality grazing and silage, paddocks are cut every other year and all silage ground is grazed in spring before closing for silage. One-third of the first cut is taken in early May with the rest in late May to spread the supply of high quality aftermath grazing.

"Cows do not lose a lot of body condition providing they get sufficient dry matter intakes. On very wet days we do not hesitate to bring cows indoors."

He says it is important to ensure cows have enough grass in front of them. If, when checked in the evening, they are running short of grass the fence is moved to offer more grass.

Breeding has focused on using high production bulls giving daughters with depth of body, good feet and well attached udders. He has bred high genetic merit cows, to take advantage of grass and so that when quotas go he is ready to step up production to maintain income.

Milk production a cow has almost doubled since 1983, and hence herd size has fallen from 310 cows to 144 cows. Replacements born in 1994 had PIN values of 37, increasing to £59 PIN for animals born in 1997.


&#8226 High yields from grass.

&#8226 Genetic merit benefits yields.

&#8226 High grass intakes vital.

Conference question time

What would you do when managing each others farms?

Donal Cashman said that with low rainfall in Leics the farm would not grow grass as well. "At home we can graze cows comfortably, but in Leicestershire they would starve. You must choose a system that suits your area and your farm."

Wil Armitage added that, in southern Ireland, he would consider running a herd of organic Jersey cows. "Grass is vital in our rations in Leicestershire, but there are only a few days when it is the quality we want to feed high yielders."

What do you think about extended lactations?

Mr Armitage is happy to accept a 14-month calving interval. That is not an excuse for poor fertility, he stresses.

"Fertility declines once a cow is four to six months calved. But its pointless serving a 60-65kg cow at peak yield when she will still produce 35-40kg at the end of lactation.

"A 14-month interval will reduce the stress she suffers around calving, producing a longer milking life and higher lifetime yield."

Mr Cashman needs a short calving interval to ensure cows calve in tight spring and autumn blocks for easier management at grass.

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