Sustainable free range poultry systems pave way for integration with agro forestry

Free-range layer flocks are often stand-alone enterprises but integration with agro-forestry can develop sustainable farming systems, according to new ADAS research.

Rising feed costs and concern over environmental risks posed by farm waste, including manure, has led to sustainability becoming a buzz word. Profit is paramount, but can layer hens be incorporated into farm woodland systems helping increase income while making good use of waste such as used litter?

That question posed at the recent DEFRA-funded workshop, Coventry, saw the release of new ADAS paper-based research collated between 2006-2008. Against a backdrop of increasing world population to nine billion by 2025 and the increase in demand for both food and fuel, sustainable systems of production are being sought.

Various arguments support integrating free-range layer flocks from stand-alone enterprises into farm woodland crops such as coppice biomass and orchards despite there being as many pitfalls as gains.

It is not necessarily a new idea, explains ADAS’s Arnold Elson. “Between 1918 and 1953 outdoor hen systems were expanding rapidly and were commonplace.


“But it’s not that straight forward. It can be problematic not only on a practical standpoint of placing, moving and servicing mobile housing in woodland systems, but also the bigger concern of predation from foxes and carrion.

“Only a small amount of research has been carried out in the past at ADAS Gleadthorpe, who are looking at incorporating free-range systems into commercial crop rotations,” explains Mr Elson.

Little information from commercial units is known on the ins and outs of integrating free-range hens into crop rotations. But it is information that the industry needs as the sector grows. “One factor that is apparent is the increase in the proportion of free-range eggs in today’s market. This has doubled from 16.4% in 1999 to 34.2% in 2007, largely at the expense of caged systems.”

Several potential options for integrating free-range hens into commercial crop rotations were evaluated in the latest study, says ADAS researcher Heleen van de Weerd.

Organic free-range systems offered one route forward. This encourages birds to supplement diet from the range reducing the amount of feed brought on to a unit. Danish studies suggest nutrient deprived hens consume 20-40g/head/day of forage compared to 10-30g/head/day for those offered a high nutrient diet. However, the level of nutrition gained varies seasonally and is almost unquantifiable.

One fact beyond repute is the increased demand for feed for organic systems. This reliance on bought-in feed remained a concern not only on environmental but also economic grounds, she added.

Nutrition also had an effect on the incidence of feather pecking and/or cannibalism. Access to ranges can cut this problem ten-fold to just 5% but research suggests the type of cover on a range is more important than the area. On welfare grounds, access to outside areas allowed hens to demonstrate normal behaviour particularly in dry, dusty areas – one of the five freedoms that embodies animal welfare codes within the UK, she said.


Integration into agro-forestry such as coppice, biomass or orchards had its supporters but experience was sparse, says Dr van de Weerd. Woodland owners are often looking for means by which income from tree-based products can be supplemented and, indeed, a small but significant number (134) had begun to market woodland eggs under a niche brand identity in the UK.

“It has been shown that feral chickens in woodland areas help increase biodiversity at all levels. However, modern commercial woodland sees some use of herbicides that may not be compatible (for integrating free-range systems). Also, the need to use machinery to move hen houses may incur damage to trees,” explains Dr van de Weerd.

The threat of predation remained high and while good electric fences would reduce the impact of ground-based animals such as foxes, the threat from carrion remained unresolved.

Integration within orchards also had limitations. Modern orchards see trees closely spaced and more varieties are bush rather than tree in stature adding to practical limitations.

Likewise, coppice stands tend to be deciduous reducing cover in winter months. While owners looking at 25-year pay-backs would welcome income from eggs, this had to be balanced against risks of hens de-budding trees, explains Dr van de Weerd.

The need to import feed for poultry crops is almost unavoidable. ADAS studies highlighted the potential risk bought-in feed posed to the deposition of nitrogen from faeces and leaching of nutrients.

Based on an 8000-bird free-range unit managed as part of a 100ha (247-acre) arable unit, researcher Anne Bhogel calculated nitrogen production was lower at 126kg/ha against 357kg/ha for a similar sized independent poultry enterprise. “The key is how to best make use of surplus nitrogen as this can lead to nutrient accumulation and eventual leaching.”

As part of an arable rotation, poultry waste had potential to be a valuable manure for following crops. However, producers had to think carefully about cropping as high nitrogen levels can lead to skin damage on potatoes, for example, and may not be fully utilised by other crops such as fruit trees.


ADAS’s John King highlighted other practical implications, namely the demand and supply for clean drinking water in addition to that needed for washing out hen housing. A free-range system of 8000 birds stocked at nine birds/sq m (0.8/sq ft) in the house and 1000 birds/ha (405/acre) on the range required 648cu m (about 142,000gal) annually for drinking and a further 5.28cu m (1161gal) for washing out.

While some producers considered rainwater captured off hen house roofs to be a solution, it had problems in both seasonal supply, storage and hygiene. “In essence it’s only a tenth of the amount [for a 8ha (3.2-acre) orchard supporting 8000 free-range hens] needed and so an abstraction source will be required.”

There are extra practical demands on water resources from incorporating poultry and agro-forestry systems. “Free-range birds will consume 10% more water that caged birds.

“The problem is many believe water is plentiful and, therefore, not a problem. However, whether it comes from a bore hole or mains supply, it is still a cost to be borne.”

For many producers it will be the financial statistics that will influence the decision on integration of egg production with commercial agro-forestry. ADAS’s John Newton’s costings suggest an additional £480/ha (£194/acre) could be generated from this approach where producers were able to secure a 2p/doz premium for “woodland” eggs from either ash woodland, short term coppice or cider apple crops.

The calculation is based on an individual layer producing 285 eggs per year, achieving a sale price of 87p per dozen with feed costing £157/t and each bird consuming 52kg.

“It is always very difficult to compare diverse systems however it does give a feel for what could be achieved,” he said.