This week, I feature a large dairy cubicle house in Connacht built by a farmer who is firmly focused on producing milk at a low cost.

Cost per cow place here is about €900 – probably lower than some winter sheds now being built in parts of New Zealand.

The list of machinery on this one-block farm is short: a rotary parlour, passage scrapers and one tractor for feeding silage.

This is a new milking set-up. A 40-unit rotary parlour was built two years ago. Now, a silage slab, open lagoon and the cubicle house have been added.

The farm extends to 320 acres and the herd is currently 300 cows. There is room for more cows and cubicles in the shed.

Picture one

The cubicle house is 12 bays long, totalling 58m, and the roof spans 42m. That gives it a floor area of 2,440m2.

The farmer’s underlying plan was to build an open lagoon for low-cost slurry storage at the bottom of a slope, to build everything else above it and let gravity do the work. So there are no tanks – slurry is scraped directly into the lagoon.

Only in the central pit of the rotary parlour, lower than the lagoon, is there a small pump to send off washings. There are no walls on any side of the silage slab. It is positioned very close to the cubicle house for efficient feeding out.

Picture two

The shed has no internal feed passage – all the roof area is used to cover cubicles, calving pens, etc. Instead, there is an external feed passage at each side of the shed.

There is no canopy over the feed passages. The aim is to have cows housed for just three months, January to the end of March, and while in the shed, they are fed on silage only, so rain isn’t an issue.

The concrete feed passage is about 5m wide – just enough to feed out silage. If the farmer wants larger concrete aprons he will build them later.

Locating the feed passages at the sides means that the shed has no side walls and no cladding is used. Neither is there sheeting nor end walls at the gables.

Picture three

The shed has 330 cubicles, arranged as five rows of doubles.

With just two feed rails, there is feeding space for 200 cows at any one time. To deal with this, the farmer keeps silage ahead of the cows at all times.

To keep baled silage out of the scrapers and lagoon, he opted for diagonal feed rails.

These cost about €250 per bay, whereas a single feed rail would have cost about €25 per bay.

But the diagonal barriers are effective at keeping out silage.

The cows have a wide step to stand on when feeding, keeping them away from the scrapers.

Pictures four and five

Passages are scraped with Alfco automatic scrapers, which push the slurry directly into the open lagoon.

Picture six

There are no cubicles in the three end bays – calving and calf-rearing pens will be built here.

Picture seven

The design of the shed is a straightforward back-to-back lean-to. There are a whopping 90 pillars under the roof. Steelwork is painted, not galvanised. The sheeting on the roof is spaced. There are no clear sheet roof lights. This and the fact that the spacing gap is relatively narrow means that not a lot of light gets in from above. Spacing of up to 25mm is used for cubicle houses in dry areas – here, it is about half that.

The farmer is conscious that if he sheets down a gable end, he will reduce the amount of light coming in. One option for him would be to use clear sheeting on the gable end.

Concrete work was carried out by Gabriel Flynn Buildings and Irish Concrete Floors. The steelwork was supplied and erected by Co Galway-firm Lyons.

Costs

The shed has cost approximately €300,000 to date, with some work on calving pens still to be done.

The lagoon and fencing cost approximately €50,000. The farmer has analysed all costs.

Construction of the lagoon required quite a number of loads of fine blinding under the liner and this drove up costs, he said.

An open concrete tank wouldn’t cost any more and, with straight sides, would catch less rainfall, he noted.

He told me that he had to buy in more stone than he expected to raise the end of the shed where ground was falling towards the lagoon.