Farm roads are an under-appreciated asset on dairy farms, with them being the literal link road between cheap, high-energy grass that our dairy system is renowned for, and the parlour.
As herd size increased post quota, extra units were added to parlours and additional slurry and cubicle accommodation were built to over winter these cows.
While additional land was taken on, in some cases, and roadways built to access paddocks, the widening and repairs of existing roads seems to have fallen by the wayside which is significantly affecting cow flow on these farms, according to Teagasc and MTU research.
Fifty-five farms were selected for the study, with herd size varying from 30 to 760 cows.
Roads were measured regarding width, surface condition score (ranging from one to five, with a score of one indicating inadequate for animal movement and five indicating optimal). The presence of crossing points was also noted, with an assessment on cow-flow dependent on the above variables analysed using cows per minute (CPM) as a metric.
A total of 893 distinct sections of roadways were analysed on the 55 farms.
The analysis found that many roadways on farms were ‘sub optimal’ for both condition and width, both of which were found to be significant factors in cow flow (cows per minute).
Just 4% of roads were found to be the optimal width or greater. The recommendation for dairy farms is to have a farm roadway width of 3.5m for up to 50 cows, with each additional 50 cows requiring an increase of 0.5m in width.
On average, roadways were found to only be 70% of the optimal width based on herd size. The above recommendations are for farmers milking in conventional parlours or rotaries, and not an apt parameter for those milking with robots which can work off narrower widths.
Regarding surface condition, the study found that only 14.2% of farm roadways were classed as optimal, with 24.4% classed as “totally inadequate”.
A public road crossing was also found to significantly affect CPM, reducing it by 32.7% on average. The study suggested that farm roadway infrastructure has not adapted to the growing herd size for commercial dairy herds, and that farmers should ensure that roadways are an optimal size for their herd to improve overall cow flow.
How to improve road condition
Correcting road width is a relatively straightforward task, but as the study results in Table 1 prove, improved road width without addressing surface condition will still lead to poor cow flow.
Crossfalls and surface material
Roadways should be cambered to remove water off the roadway quickly, which will reduce the cost of maintenance mainly through removing the likelihood of potholes developing.
To remove water quickly from roadways, they should slope to one or both sides, with a slope of 1:25/2.3° recommended.
A roadway that slopes to one side is easier to construct. However, livestock flow is generally better on roads that have a gentle camber from the centre to each side.
Where roadways run alongside a watercourse, the camber should be constructed so that soiled water is directed towards the field and not the watercourse.
The finished level of the road should be above the field level to allow water to drain off the road.
Crossfalls should be put in place with the fill material (200mm to 300mm installed) to allow even distribution of the surface layer. A fine surface layer (eg quarry dust) should be evenly applied and compact rolled using a vibrating roller.