Drimoleague in west Cork was the venue for one of the Grass 10 spring farm walks on Tuesday. The host was Jerome O’Mahony, who along with Paul Forbes are milking 162 cows on a 40ha milking platform.

Despite heavy rain and very blustery conditions, the cows were out grazing on the day of the walk.

Jerome says there are three ways of classifying grazing conditions.

“The first is when things are hunky dory, the weather is good and cows are out day and night – it’s easy to manage that.

"The next is what I classify as intermediate or wet. Let’s say cows are on 4kg of meal per day, we’ll feed them 1kg at the morning milking and let them out to grass.

Jerome O'Mahony's farm in Drimoleage has a farm cover of 1,280kg/ha.

"They’ll graze away for a few hours and then they’ll lie down. We’ll go out then at 2 or 3pm and give them another fresh break of grass, this time around three-quarters of their night time allocation.

“They’ll come in for milking at around 5.30pm and get 3kg of meal in the parlour and then back out to another fresh break, but this time they’ll only get the remaining one-quarter of their night time allocation.

“We find that after an hour or so they’ll be so full up they’ll lie down and won’t do any more damage.

"If there’s real downpours of rain we’ll go on/off grazing but the cows stay out full time as best we can. The stress levels go down when the cows are out.”

The system of giving three allocations of grass was a new one for me, but it seems to work well.

While there’s a bit of extra work involved in moving another wire, Jerome says it’s quicker than cleaning cubicles or feeding out silage. No silage is fed to milking cows when there is sufficient grass on the farm, so the spring diet is grass and meal.

I did a grass course a few years ago and it was only then that I realised the issue was we weren’t getting enough ground grazed in February

They back-fence religiously so cows never go back over areas that have been grazed.

“We never really had a problem here with getting grass into cows during the first rotation. Historically, we would have been very tight in the second rotation and would typically have been feeding 5 or 6kg of meal per cow in April because we hadn’t enough grass.

“I did a grass course a few years ago and it was only then that I realised the issue was we weren’t getting enough ground grazed in February.

"I was giving them small bits of areas and thinking I was doing a good job because I was saving grass but I was actually doing the wrong thing.

Paul with Jerome O'Mahony.

"We need to get 30% of the farm grazed in February to make sure we have a good cover of grass back on that land for the start of the second rotation,” Jerome said.

At the moment, the area that should be grazed is below what it should be. Jerome is supposed to have 15ac grazed, but only has 2ac grazed at present.

The planned start of calving was 8 February, but Jerome has 20% calved already. To get the area grazed they are going to have to continue grazing light covers.

At the moment, he has four paddocks with covers less than 1,000kg/ha and six paddocks between 1,000 and 1,200kg/ha.

He also has high covers, with five paddocks that have covers greater than 1,600kg/ha.

Jerome says these will be left until early March and he has no problem grazing strong covers then. His attitude is that bad grass is still a better feed than good silage.

His average farm cover is currently 1,280kg/ha. The farm had a closing cover of 810kg/ha on 1 December so average growth over the winter was a massive 11kg/day. Soil temperatures are measured locally and they didn’t drop below 10°C all winter.

Land type

The O’Mahony farm at Drimoleague is typical west Cork ground. Jerome says you could have four soil types in one field.

The land is hilly and generally free-draining but there are some wet paddocks.

Grazing infrastructure is good, with a new underground slurry tank providing stone for the construction of extra roads last winter.

The stocking rate on the farm is high at 4.1 cows/ha on the milking platform and 3.67 cows/ha overall.

The heifers are contract-reared, some silage is bought and some cows are wintered off-farm.

There’s no tractor on the farm; contractors do most of the machinery work

When the bull calves are sold and the heifer calves go to the contract-rearers there will only be one group of animals on the farm.

There’s no tractor on the farm; contractors do most of the machinery work including spreading fertiliser. The only thing done in-house is feed cows with a loader.

Last year, the herd produced 493kg of milk solids per cow but meal feeding was 1.2t/cow higher than the previous year when stocking rate was lower and the weather was better.

Jerome said that milk solids per cow increased by 80kg/cow in 2018 which paid for the extra meal fed, but that it was more or less breakeven.

When it comes to grass varieties, Jerome has moved away from monocultures and is sowing mixtures of tetraploid and diploids now

About 85% of the farm has been reseeded since 2011. Prior to that, Jerome says growing more grass wasn’t on the radar as the output was limited by milk quotas.

When it comes to grass varieties, Jerome has moved away from monocultures and is sowing mixtures of tetraploid and diploids now.

He says he has been using the Drinagh Co-Op D74 mixture which is made up of Aberchoice, Abergain and Drumbo.

Fertiliser was spread on 13 January at a rate of 25kgN/ha or 20 units/acre of urea.

The next fertiliser application will be 250kg/ha (two bags/acre) of 18:6:12 later this month.

Jerome O'Mahony's farm in Drimoleage has a farm cover of 1,280kg/ha.

However, if the ground is wet and the weather is bad Jerome says he will go with urea instead, as this is more stable in the soil than compounds.

If the 18:6:12 is spread in February then he will go with more urea in late March.

Fertiliser

A few people in the crowd were asking if fertiliser was spread on the high covers and if 18:6:12 will be spread on them too.

Jerome says that he will blanket-spread the whole farm with fertiliser regardless of the cover, saying the fertiliser is for the regrowth more so than the grass that’s there now.

He says there’s no lag time between grazing and re-growing when there’s enough fertiliser out.

Another question referred to what happens if magic day is later than normal, like it was in 2018.

Jerome answered by saying if he needs to wait until early April to know that magic day is late he won’t have done his job properly as measuring grass regularly will tell him what is happening on the farm well in advance.

  • Grass10 farm walk in Drimoleague, west Cork on Jerome O’Mahony’s 40-hectare farm.
  • Jerome is milking 160 cows and should have enough grass to keep cows out grazing full-time.
  • His aim is to get 30% of the farm grazed in February using on/off grazing and feeding as little silage as possible.