Grass-based farmers should aim to breed a dairy cow to have her calving as close as possible to the expected turnout date, according to Teagasc’s Seamus Nolan.

The Teagasc Dairy Advisor said that the key to a profitable grass-based spring-calving dairy cow herd is to produce as much milk as possible from grass.

“The longer the lactation of a dairy cow the more profitable she is going to be.

“Most spring milk producers have their cows dry by December, so a cow that calves during February will have a longer lactation than a cow that calves in March or April.

Generally later calving cows produce three weeks less milk.

Nolan, who contributed to the Aurivo and Teagasc Dairy Handbook, said that to achieve this target, dairy farmers should start to carry out heat detection three-to-four weeks before the breeding season.

“This will allow farmers to pick up the problem cows that have calved more than 40 days,” he said.

Nolan also said that farmers can scan or metricheck their cows prior to breeding, to identify cows that may be suffering from an infection, which may stop the cow from cycling normally.

About five-to-10 cows in a 100 cow herd may be suffering from infections, if the problem is not picked up on prior to breeding, the cow could end up going from an early calver to a late calver.

This is important as Teagasc research shows that each 1% improvement in six-week calving rate will lead to an €8/cow increase in profit.

It also shows that increasing the national average six-week calving rate of 57% to 90% would be worth an additional €20,000 to the average Irish dairy farmer.

Heat detection

Nolan also said that at the very least dairy farmers should use tail paint to detect their cows coming in heat.

Teagasc research shows that each missed heat costs dairy farmers €250/cow, mainly due to a reduction in milk production.

Nolan also said that farmers may consider using hormone treatments for the later calving cows in their herd, as this will tighten up the calving pattern for the next year.

Teagasc shows that the most profitable dairy farmers achieve a six-week calving rate of 90% and a submission rate of over 90% in the first three weeks of the breeding season.

Tips on heat detection:
  • Use a heat detection aid such as tail paint, scratch cards or teaser bull
  • Tail paint cows in April
  • Record heats but do not commence breeding until May 1
  • Examine non-cycling cows and these cows may need veterinary intervention
  • Begin AI from May 1
  • Record insemination date
  • Observe cows in the paddock three times per day, before morning milking, evening milking and again late in the evening
  • Top up tail paint regularly, so cows without paint can be quickly identified and mated using AI
  • Breed cows with AI for the first eight weeks of the breeding season; breed remaining cows with a bull for a further five weeks
  • Heifers can be synchronised (AI for six days, inject day seven) with bulls let out after two weeks