The rising cost of straw in recent years is increasing the cost of wintering ewes for many farmers. This is especially true of farmers outside of tillage areas, with transport costs a significant component of the overall cost of straw.

While rising costs are a concern, of equal worry for some farmers is the ability to source the volume of straw they require regardless of cost. This is leading to some farmers reviewing housing arrangements and an increasing number are undertaking new builds or carrying out remedial works to winter accommodation, opting for slatted floors.

The situation is similar for farmers across Ireland and the UK. An on-farm study took place in recent months in Wales under the Farming Connect programme to assess floor type and bedding options for wintering sheep. The initial findings were presented in an insightful webinar chaired by Elan Davies, red meat technical officer for Southeast Wales.

Elan said the price of straw is at an all-time high in Wales and the study was carried out to evaluate if slatted floors could be a viable alternative.

The study was carried out on Hendre Ifan Goch Farm, operated by Rhys Edwards and his father Russell. The farm is a participant in Ram Compare and Grass Check projects as well as being a Farming Connect demo farm. It had already been experimenting with alternative floor options.

Rhys said there were three reasons for their investigations. Firstly, the farm has been finding it increasingly difficult and costly to source straw. Last year he only managed to source 20 big square bales when normally they would have purchased anywhere from 140 to 160 bales.

Labour was also a big component, not so much on a daily basis, but cleaning out penning once a month was a big job.

He was also having significant issues with lameness and wanted to see if a move to slatted floors would help keep issues at bay.

Initial experiments

The farm was initially reluctant to install slatted tanks and experimented with a number of lower-cost options that involved positioning the slats above ground level. The first experiment was with expanded metal and security fencing raised on top of pallets but Rhys said the 10mm gaps were not wide enough and the fleece of sheep became excessively soiled.

Another option explored was chicken slats elevated above ground level. However, the 25mm holes were too big for some breeds and resulted in some animals catching their feet. Pig slats with a 10mm opening were also deemed too narrow to keep the slats clean, while an option that appeared to be working well was plastic pallets imported from China with a 14mm gap. The cleanliness of sheep was good on these, as was the comfort, but the downfall was they were not strong enough and cracks started to appear after four weeks.

These options were experimented with in small sections of the shed as lower-cost alternatives to installing plastic slats. Rhys knew plastic slats worked well after visiting a number of farms to assess different ways in which the slats and feeding passages could be easily raised.

However, they would be costly and labour was still going to be significant. All slats would need to be lifted for cleaning the area with a bobcat at least once and possibly two or three times depending on the length of the indoor feeding period. This would leave the farm no better off in terms of labour input so the decision was taken to install underground tanks.

Tank installation

A shed with a portal frame allowed the easier installation of two 4ft deep tanks, leaving room for a centre passage. The shed was also extended on both sides by 7ft to allow feeding on both sides, with the gable walls easily removed and the height at the eaves allowing the roof span to continue. Vented sheeting was installed on the gable ends as the shed is in an elevated and exposed area. Sliding doors at both ends improve the air inlet capacity if required on calm days.

A feeding space allocation of 8in to 9in is sufficient to house 540 ewes while there is enough slurry storage for this number of ewes for a 100-day winter. The investment also opens up the opportunity to finish store lambs indoors if required.

Extra housing

In addition to the slatted shed, there is extra housing on the farm. This allowed for the investigation of four bedding options in addition to plastic slats – wheaten straw which was typically used on the farm, barley straw, sawdust and Envirobed, which is a waste paper-type product.

The trial was designed by independent sheep consultant Dr Liz Genever. Five areas were evaluated, including the volume of bedding required, ewe cleanliness, cost, labour required and incidence of lameness. The trial ran for six weeks, with time measurements on aspects such as labour input collected by Rhys and Russell.

Ewes were stocked at a low stocking rate (2.1m2/ewe), with the volume of bedding also kept in line with levels recommended. The ewes on slats were stocked at 0.8m2/ewe. This was higher relative to the bedding options but was needed to keep faeces pushed down through the slats. Wheat and barley straw cost £100/t (€117/t) delivered, EnviroBed cost £186/t (€219/t) delivered and sawdust cost £20/t (€23.50/t) ex farm.

Sawdust required the highest volume of bedding, with 900kg used. EnviroBed was not far behind with in excess of 800kg used over five weeks (the final week using EnviroBed was suspended due to the fleece of ewes becoming excessively soiled). There was about 350kg of wheaten straw used and 300kg barley straw.

Figure 1 details the direct cost of bedding, the labour cost attributed to each system at a cost of £12/hr (€14/hr) and the cost of these two factors combined.

EnviroBed was by far the most costly at about 30p/day. There was a high volume of sawdust used, which increased the labour cost, but the lower direct cost compensated for this, leading to an overall cost of about 11.5p/day. There was little difference between this and the two straw products, with wheat straw at 12p/day and barley straw at 11p/day.

Liz said the cost attributed to the slatted floor option was calculated to take account of depreciation, as is standard in such investments. The total cost of constructing the two 90ft long tanks and slats for the 22ft wide span was £18,000 (€21,175). This excludes the cost of machinery and labour carried out by the farmers, as well as work to the structure of the shed.

The slats, which were made in Germany, have a 10-year guarantee and it is assumed the investment will still possess a residual value of £5,000 (€5,882) after 10 years have passed. The depreciation value was therefore taken as £1,300 per year.

When spread across 500 ewes housed for 100 days, this equates to 3p/ewe per day. There will likely be an interest cost if borrowing is required but this will depend on each individual situation. Also, it is worth noting the cost would be higher if contracting someone in to complete the entire job. However, in this case it represented a very attractive investment and provides a good template for farmers to review their own situation and costs.

Rhys says he may have saved £2,000 to £3,000 on the slats if he did not opt for the MIK Stepper Sheep Slats (800mm x 600mm in size).

However, in doing so he says he would have had to accept a much shorter guarantee, or in cases no guarantee at all. While he highlighted the MIK Stepper slats have a greater load bearing capacity of 200kg per section and require fewer support bars across the tank.

Ewe cleanliness

Ewe cleanliness was assessed on a weekly basis and was viewed as an key component of the trial given the knock-on consequences for the health of ewes and lambs at lambing. The slats came out on top in terms of keeping ewes cleaner, followed by barley and wheat straw.

The EnviroBed material kept ewes relatively clean but Rhys says it required such a high level of topping up that it became unsuitable and was discontinued after five weeks.

The sawdust kept ewes clean for four weeks but then deteriorated quickly as a layer of material accumulated under ewes. Rhys says that for sawdust to be a runner it would probably have to be cleaned out every four weeks while he sees some potential in starting with a base layer of sawdust and applying straw with a straw blower on top of this to reduce overall straw usage.

Other things to consider for slatted floors

When assessing the potential of slatted floors there are also other management factors that need to be taken into account.

  • Ewes can be lambed on slats but lambs need to be promptly removed as there is a greater risk of body heat being lost due to the poorer thermal conductivity. This differs across slatted floor types, with plastic slats preferred by many farmers over concrete, mesh and timber slats for lambing. In the Edwards case, ewes were being moved to straw bedding in advance of lambing as there are no lambing facilities present in that yard and sufficient space is available elsewhere.
  • Some farmers have found slatted floors can provide less comfort for aged ewes in high-prolificacy flocks but this varies between floor types and aspects such as the length of time that ewes are housed.
  • There can be issues with slats clogging where silage is being pulled into pens. Rhys says this was an issue in another concrete-floored shed where ewes were pulling in silage under the barrier. He thinks they have overcome this in the slatted shed by providing ewes with more feeding space, which he says reduces the pressure on ewes.
  • Rhys said there was a concern at the outset that ammonia being released from the slatted tanks could be an issue along with draughts circulating under sheep. Inserting 1ft to 18in of water in the tank at the outset has prevented any issues, with no smell in the shed.