This week’s Buildings Focus took Agriland to Co. Fermanagh to see a mono-pitched designed calf shed on the farm of Aidan McManus.

The Fermanagh native farms alongside his father Kevin, which sees them milk 200 cows all year round indoors, with the help of three robots.

Over the past decade, since returning to dairy farming having previously kept sucklers for a number of years, the father-and-son team had focused their attentions on the cows and getting the right infrastructure in place.

This included getting three milking robots up and running and getting two cubicle sheds built during this time.

So when the time came that Aidan and his father were happy with how the cows side of the farm was the way they wanted, they looked next at improving their calf-rearing facilities.

The journey to what they have today has been in the works for the last two years, but gathered momentum in the middle of last year before being completed in December gone by.

Aidan McManus inside his new calf shed

Speaking to Agriland inside the new calf shed, Aidan said: “We have been thinking about building a new calf shed for a while, but we wanted to get the cow side of the farm in order before focussing on the calf accommodation – which some might say is the wrong way around but it’s what we did.

“It was last year when we said to ourselves that we we’re happy with how the cow side of the farm is in terms of infrastructure, and said it was time to look at improving our calf-rearing facilties.

“Our original rearing facilities were outdated and not fit for purpose and we were using more than one shed to house our calves, so we wanted one shed where we could keep all our calves and basically streamline this side of the farm.”

The mono-pitch design: Optimising animal welfare and performance

The concept of the mono-pitch design or ‘calf mono’ was developed by Jaimie Robertson. In England and Scotland, this type of calf shed design is more commonly found but not to any major extent yet, whereas here in Ireland it is a new concept really.

The key features of the design of such a shed revolves around ventilation, both natural and mechanical – but with the idea of optimising natural ventilation and this is the idea of having a big slope at the back and a small one at the front of the building – drainage and ease of cleaning out.

All these features together are to achieve the end goal of optimising animal welfare and performance.

Going with the mono-pitch design

Aidan said himself that he didn’t know exactly what sort of a calf shed he wanted at first and he flirted with the idea of calf hutches/igloos. But, from talking to Teemore Engineering, he was sold on the mono-pitch concept and liked the idea of his calves being housed in such a facility.

Looking at the design Aidan landed on, it’s a four bay shed with a passageway to the front of the shed and a narrow and shallow slurry tank running the breath of the shed just inside the front of each pen.

The building measures 19.2m long and 9.9 wide. Each bay is 4.8m wide.

The key features of the shed

First off, before even looking inside the shed, it catches your eye straight away looking at it from the outside with it’s long-sloping back and narrow front.

Looking at the front of the unit, it consists of four sheeted doors and above each door is a windbreaker, which each have a cord that allows for it either to be pulled down to the top of the gate or back up to just below the eves.

The idea of the windbreaker is in the name, but the fact it can fold up and down with the ease of the cord just makes life for the operator. For instance, if Aidan wanted to clean out the shed and drive in with the teleporter on say, warmer days, he could fold up the windbreakers to let more air into the shed.

Despite each door leading into each of the four spans being covered in sheeting, they are still quite light in weight.

Moving inside the shed, a passageway the length of the shed was incorporated and acts basically as a work area and a way to be able to go between pens without having to exit the shed and go in through one of the other doors.

In this passageway, a second-hand Lely automatic calf feeder can be found, which serves two pens. Also found along the passageway, attached to two of the girders, are water taps.

At one end of the passageway, a fifth sheeted gate can be found – which again just offers another access point into the shed.

Moving deeper into the shed, specifically into the four pens, Aidan said that 20 calves could fit in each pen comfortably.

At the front of each pen are feed barriers which you would find commonly in sheep sheds but do as good a job for calves. Built into each feed barrier is a small access gate which allows for quick entry in and out of the pen without having to open out the whole feed barrier completely.

There is an adjustable rail on the feeding barrier which allows Aidan to adjust the height of it to suit the calves feeding out from it.

Just inside each feed barrier is a narrow slat – which runs through the entire breadth of the shed – that is connected up to a slurry tower beside the calf shed.

The narrow tank is a mere 2ft deep and serves to keep each of the pens dry – by taking away any moisture from the bedding at the back of the pen.

To aid with the draining, a 1:20 slope is incorporated from the back of the shed, running down to where the tank is at the front of the pen. Also towards the front of each pen is a small JFC water drinker.

Again, the water trough is positioned where it is in case a leak was ever to occur so that it wouldn’t dampen the bedding calves would be lying on and any water could drain quickly down into the tank.

In time, the plan is to put a plank of timber between the slat and the bare concrete at the back of the pen to stop straw from being dragged to the front of the pen and blocking up the slat.

Another feature of the shed which grabs your attention straight away is the polypropylene walls.

The idea behind the installation of such material – which is generally found in pig units – is for ease of cleaning when washing down pen(s) after use.

These polypropylene walls are also fitted along both sides and at the back of the shed.

These polypropylene walls are fitted into channelled precast walls (as can be seen in the pictures below).

The idea behind the polypropylene walls fitted into channels rather than just being rested and fitted on top of concrete is that when you would be washing down the pen, the channels in the walls prevent water and any possible diseases from entering the adjoining pen.

Going around the sides and back of the shed is Yorkshire Boarding. The Yorkshire boarding allows air to come in but no rain blowing into the shed.

An important aspect of this design of shed is where the shed is facing. The back of the shed should be faced towards the prevailing wind. This is to maximise natural ventilation in the shed – which is the overall goal of a shed like this.

Another interesting feature of the shed is that at the back of it, there is a single sheet of galvanise going the entire length of the shed directly below the roof of the shed itself.

The idea behind this single sheet of galvanise is that when air comes in it travels up the building. So, if the calves are lying at the back of the shed, the air is not coming in and hitting the first timber purlin – because if it did it would drop and fall down on the calves and as such, create a cold environment for calves.

The idea of the sheeting at the back of the shed is basically to drive the air up above the level of the calves and create a draught-free environment and yet still have air still constantly changing in the shed.

Airflow in and out of the shed is further enhanced by a ridge at the apex of the shed.

Looking up at the ceiling of the shed, you will see a VentTube Cool system installed. The function of this system is to circulate air in the shed but the idea is that you shouldn’t feel the air from the system 1.2m above floor level so as to avoid blowing cold air on the calves.

Aidan said that on calm days when there is no real wind and on the days when the shed could get stuffy, this system will really come in use to help keep air moving in and out of the shed. This system costs £1/day to run.

Other features in the shed include a single skylight sheet in each bay and a fixed light in the pen for when Aidan might be in the shed working after daylight hours. Fibre cement sheeting is also on the roof.


The cost of the shed came to £50,000, excluding VAT. This cost also excludes the second-hand automatic calf feeder that was installed.

The fact that Aidan and his father were able to do all of the building work themselves – with the wiring of the shed the only part contracted out – it has saved them £10,000.

The entire shed – with the exception of the wall channels and tank – were supplied by Teemore Engineering. B. McCaffreys supplied the wall channels and tank.

Speaking about his decision to build the shed, Aidan said: “Look, it was a case that we needed to build new calf housing.

“We only got into the new shed just after the Christmas but so far, I have been happy with it.

“There’s a pen of calves on the point of weaning there that have been housed since they were born and they have done a good thrive and so far, thankfully, we have had no health issues with any of the calves.

“The ease of which the pens can be cleaned out is also a huge plus. Before, you’d spend ages cleaning out the old sheds.

“Whereas now, all you have to do is open up two gates and straight in with the teleporter to clean it out and bed it again in minutes,” Aidan concluded.