Paddocks on most Irish dairy farms were designed 20 years ago and, as a result, they compromise on the cows’ performance from grass, according to Teagasc’s Patrick Gowing.

The Head of the Teagasc Dairy Expansion Service spoke at a Teagasc/Glanbia Monitor Farm Walk on Shane O’Loughlin’s farm in Monasterevin on Tuesday, which was attended by over 50 farmers.

Gowing said that dairy farmers have increased their cow numbers over the last number of years and priortised spending in the yard rather then in the fields. And, as a result, the paddock size on a number of farms are too small.

“Cow numbers have increased on dairy farms, but the paddock size has remained the same, which has a negative impact on cow performance during June and July,” he said.

Farmers should aim to have a paddock big enough to graze the cows for 36 hours or 1.5 grazings, he said.

Dairy farmers should aim for two good grazings followed by one tight grazing to ensure that the paddock is cleaned out.

“To get a good graze out you have to push your cows, but if you are pushing your cows everyday it will have a negative impact on production.

“Milk protein levels will drop in June and July if your paddocks are too small and you are pushing your cows tight at every grazing,” he said.

Farmers should aim for a milk protein content of 3.5% in May and instead of it falling during the months of June and July, the protein content of the milk should increase slightly, Gowing said.

Gowing also said that it doesn’t cost a lot for dairy farmers  to change the size of their paddocks.

“When you go back to 18 paddocks, the grazing management becomes easier and farmers should also see an improvement in cow performance,” he said.

Grazed paddock showing signs of recovery on Shane O'Loughlin's farm in Monasterevin.

Grazed paddock showing signs of recovery on Shane O’Loughlin’s farm in Monasterevin.

Calculating paddock size

Gowing also discussed how to calculate the paddock size dairy farmers need for their dairy herds.

The calculation involves the herd size, the daily grass allowance and the target number of grazings from each paddock along with the opening grazing cover.

Grass required = Number of cows x Daily Grass Allowance x Number of grazings

Example: 180-cow herd

Grass required = 180 cows x 18kg of grass x 1.5 grazings

Grass required = 4,860kg of grass

Once the amount of grass required is calculated, you then divide it by the targeted grazing cover less the residual. 1,400kg – 100kg residual = 1,300kg/ha

Paddock size = 4,860/1,300

Paddock size = 3.73 hectares.

Gowing also said the shape of the paddock has to be considered and in an ideal situation the paddocks should be as long as their are wide.

However, he said that twice as long also wide also works well, as it reduces the amount of walking the cows have to do to access grass in long narrow paddocks.

“In long paddocks, cow do to much walking to get to the back of the paddock, which could cause difficulty during difficult grazing conditions,” he said.

Grazed paddocks showing some signs of recovery

Cows grazing

Road ways

Gowing also spoke about the ideal roadway structure on farm. He said that the width of the roadway depends on the number of cows in the herd.

He also said that roadways should be widest at the parlour, to aid cow flow and all roadways should have a good surface to reduce the incidents of lameness within the herd.

The Teagasc representative said that 90 degree turns should be avoided on roadways as they can cause bottle necks, which slows down cow flow to the parlour and farmers should use sweeped bends where possible.

Roadway width:
  • Herd size <80 cows: 4-5m road width
  • Herd size <120 cows: 5m road width
  • Herd size of 120-250 cows: 5.5m road width
  • Herd size of >250 cows: 6m road width

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