Calf housing is perhaps the most difficult type to get right when it comes to livestock.

The goal should be to keep calves in a warm, dry environment – all the time reducing disease pressure, as calves grow and develop their immune systems.

The shed must also work well from a labour point of view, being easy to clean out, bed up and feed calves in.

To achieve these goals, certain design elements must be completed.

Flooring

The main priority in flooring is to extend the lifespan of the bedding material used through directing effluent from urine and dung away from dry areas and into wet areas, or channels. To do this, the slope of the floor needs to be cambered towards the channel. The Departmental recommendation is that floor be sloped at 1:20, in that for every 20cm, floor level drops by 1cm.

However, some farmers find this overkill, and it makes the bedded area difficult to clean out with a front-end loader or telehandler, while the uneven floor can make it difficult to hang internal gates. Reducing the slope down to 1:15 for non-grant spec builds will work fine in many cases.

In wet areas, there isn’t a specific need for overly gripped floor surfaces, such as would be seen in collecting yards or high-traffic cow areas.

A brush-style finish on the concrete, with the brush pulled parallel to the feed barrier/front gate will give ample grip. It’s important to remember to direct and grip/grooving to run the opposite way to the main path that stock will be moving.

Bedding

With the increased cost of straw in recent years, farmers are looking at more ways to reduce straw usage, which can be a double-edged sword, whereby a penny saved in straw can be a pound lost in antibiotics or mortality. Chopping straw will increase absorbability and reduce usage by 10-15%.

One of the simplest ways to reduce straw usage without impacting calf thrive or health is to have separate wet and dry areas for feeding and lying down, with the dry area towards the back wall of the shed and the wet area along the barrier. Many farmers have incorporated this design in to new calf houses, with a concrete plinth separating both areas. The plinth should be 150-200mm in height to prevent straw being dragged on to the wet area. To allow for drainage, sewer pipes can be cut in half, with the wide end facing down, before the plinth is installed.

Ventilation

Ventilation is possibly the trickiest, but most critical element of housing to get right. Too little and scours and pneumonia will tear through the shed, and too much ventilation will result in cold calves who fail to thrive.

Scottish expert Jamie Robertson spoke to the Irish Farmers Journal a number of months ago, and was of the firm opinion that a ventilation tube was required for all calf houses. Mechanical ventilation is generally only used in calf houses where natural ventilation is of sub-standard and not easily rectified, but due to their small size, the ‘stack effect’, whereby heat from animals’ bodies rises up and out a ridge, is not particularly effective for young calves in Robertson’s opinion, which is why he recommends mechanical ventilation.

Farmers opting to use natural ventilation should know exactly how much air inlet and outlet space they should have in their housing. The inlet size should be 0.08m/calf on sheltered sites and 0.05m2 on exposed sites. While Teagasc and Department specifications would dictate that the air outlet at the ridge be 50mm per 3m building width, Roberston again disagrees with this and would argue that the air outlet should be dictated by the stocking density of the shed. Using a stocking capacity of 80 calves in a shed, the air inlet should be 6.4m on normal sites, with an air outlet of 3.2m.

Doors should be closed, and any gaps underneath them effectively sealed to prevent low level draughts. The ideal form of air inlet spacing is Yorkshire boarding, with laths running both sides of the purlin on the side in a staggered manner. A gap at the eaves of the building also works well, provided there is an overhang to prevent rain entering.

Space

Calves require a pen space of 1.8m2 per calf. In a standard bay of 4.8m long and a pen depth of 6m, giving a gross floor area of 28.8m2, a pen should only be stocked at 16 calves. This includes the wet and dry areas, with a total floor space of 2.3 -2.5m2/calf floor area (including the feed passage).

Overstocking pens will increase the disease pressure on calves, especially in younger animals. Using an outdoor lounging area of a woodchip pad, or access to a paddock for older calves, will also help reduce disease pressure on pens. Passageways between pens should not be less than 1.2m to allow for servicing with milk carts, etc.

Ease of use

How easy a calf house is to clean out will often dictate how frequently a shed is cleaned out. Calf houses should be designed in a manner that calves do not have to be mixed or moved out of the shed to facilitate cleaning out. Using the wet and dry areas, as mentioned above, will allow for calves to be shut in to one area while the other is being cleaned out. Gates should be designed in such as way to facilitate this. To allow for access for mechanical cleaning out with a tractor or telehandler, each area should be a minimum 3m in width, and ideally wider, with a sliding or roller door servicing each. Passageways should also be accessible with a tractor to allow for pallets of milk replacer, meal or bedding to be dropped at the doorway. Beyond this area, passageways can be reduced back to the minimum width, as listed above.

In short

  • Floors should be sloped towards effluent channels at 1:20 or 1:15 of a slope to keep bedding dry.
  • Bedding needs to be frequently replenished to keep calves clean and dry. Don’t skrimp on straw.
  • Good ventilation without creating draughts is difficult to achieve but is critical for calf health.

    • An example of a timber board that slots in to the ground to separate wet and dry areas.

    Floors should be cambered towards effluent channels.

    Using sewer pipes cut and placed at the bottom of a concrete plinth, as above, will allow for effluent to move off the dry area and towards the wet area.