A two-year AHDB-sponsored field lab on strip grazing in outdoor pig production systems is in the pipeline for Spring 2021. The group are looking for farmers interested in strip grazing and willing to host a trial on their farm, to analyse the effect of strip grazing on sow performance, health, grass coverage and biodiversity of plant species, nutrient content of the soil and nearby water sources.
Five or six additional farmers are also welcome to join the field lab group, and all will have the opportunity to contribute ideas around the trial design and closely follow progress at the host farm. If you are interested in being involved, please contact email@example.com
Why is the research needed?
Outdoor pig production systems are under pressure to reduce their impact on the environment. Current commercial set ups with high stocking densities lead to hotspots of nutrient deposition. The capacity of soils to store phosphorous and nitrogen in these hotspots is often exceeded and these nutrients enter surface water as runoff, causing eutrophication. Sows are often moved onto land where vegetation cover has little opportunity to establish and is difficult to maintain due to wallowing and rooting behaviours. This reduces the ability for plants to absorb and utilise these excess nutrients.
Strip grazing involves fencing off an area of the paddock and frequently moving the boundary to reveal a ‘strip’ of fresh grass. Most outdoor farms see a production boost when they move onto fresh sites, so strip grazing dry sow paddocks may mimic this process.
What are the benefits to the farm?
Strip grazing allows larger amounts of the paddock to recover from over-grazing and helps maintain grass coverage. Other potential benefits of strip grazing include:
- Reduced soil erosion
- Health benefits to the herd
- More even distribution of nutrients from faeces and urine - potential to reduce nutrient leaching to nearby water sources
How will it work?
With further input needed from the farmer(s), the group anticipate that at the host site, dry sows will be onto a land with a well-established herbal ley. A section of the site will be fenced off for use as the strip grazing paddock, whilst the rest of the site will be used as a control plot reflecting standard practice at the farm. A dry sow arc will be modified to have a skid frame, floor and feeding troughs mounted to the sides in order to enable the arc to be moved between sections of the strip grazing paddock.
Staff from Severn Trent Water, Kingsgate Nutrition and AHDB will support the host farmer throughout the stages of the trial. The group hope to apply to Innovative Farmers for funding to help cover the costs of constructing a bespoke arc for the trial.