Animal welfare and extensive farming in the dehesa

The dehesa is not a forest. It is a landscape people have maintained for centuries so that animals can live under oak trees. It is credited with a great many virtues, some of which do not survive checking. Here is what can be said about it with sources, and what cannot.

Where this information comes from

The surface areas and the definition of the dehesa come from the Libro Verde de la Dehesa, the Spanish scientific consensus document, and from the Portuguese national forest inventory. The stocking densities come from European directive 2008/120/EC and from Real Decreto 4/2014. The protection status comes from the Habitats Directive and from the UNESCO MAB programme records.

We sell ham that comes from this dehesa, so we have every interest in speaking well of it. That is exactly why we checked each claim before writing it, and why we removed several.

What a dehesa is

The reference definition is precise: a farming system in which at least half the surface is pasture, under a canopy of scattered mature acorn-bearing trees, that canopy covering between 5 and 60 % of the ground. In other words, neither forest nor meadow, but a maintained middle ground.

Around 3.5 million hectares in Spain, across 1,300 municipalities. Extremadura holds 35 % and Andalusia 27 %, but Castilla-La Mancha holds 21 % and Castilla y León 13 %. It is in the latter that the province of Salamanca sits, where our pieces come from. In Portugal, the montado adds close to another million hectares.

On its age, some caution is due. The word dehesa appears in medieval texts, but it then meant enclosed private pasture, with no reference to a type of vegetation. The open wooded parkland we know today took hold in the nineteenth and twentieth centuries. You will often read “two thousand years”: the standard historical research does not say that.

The space, in figures and on the ground

This is the most telling figure, and it needs no commentary. Every value here is set by regulation.

Minimum space per animal. During the montanera, stocking is capped at 0.25 to 1.25 pigs per hectare depending on tree density, which gives the areas shown.

The gap runs from one to several tens of thousands. This is not a judgement on indoor farming, which feeds most of the population and follows demanding rules. It is simply a different order of magnitude, and it explains a good part of the price of an acorn-fed ham. What the animal eats in that space is covered in our article on what the Iberian pig eats.

That space is not only a matter of comfort. The pig has no functional sweat glands for evaporative cooling: it regulates its temperature through behaviour, seeking shade and wallowing in mud. Under the oaks it can do so. That is a physiological constraint, not a preference.

Those figures are the law’s. These are the ones from the farm our pieces come from, in the Salamanca dehesa, where we go in every season.

There, the montanera runs at roughly one hectare per animal, ten thousand square metres each. Set that against the table above.

The plots mix holm oaks and cork oaks. The tree cover is not uniform: it changes from one plot to the next, and the landscape changes again with the seasons. That is precisely why the standard works in a range rather than a single figure.

There is a large watering point and natural shelter, and the farm is properly equipped: it is a complete operation, which makes its own feed mix for use outside the montanera. It is not certified organic, and we will not present it as such.

We will not say more about it, and that is deliberate: it is not our farm, it is that of a producer we work with.

The five freedoms, and what they are worth

They get quoted the moment animal welfare comes up. They were formalised in 1979 by the British Farm Animal Welfare Council, following on from the 1965 Brambell report: freedom from hunger and thirst, freedom from discomfort, freedom from pain, injury and disease, freedom to express normal behaviour, and freedom from fear and distress.

Two points almost nobody makes. This framework has no binding force in the European Union: the legal obligations are set by directive 98/58/EC, which does not mention the five freedoms. And the council that formulated them was renamed the Animal Welfare Committee in 2019.

None of that takes away their usefulness as a framework. It simply means that announcing “we respect the five freedoms” is not a certification. It is a statement.

What the dehesa does to the landscape

On biodiversity, the credible figures are more modest than the ones in circulation, and telling enough. The Andalusian administration counts around sixty breeding bird species in its dehesa formations, more than twenty mammal species, and as many reptiles and amphibians. Among the birds, the Spanish imperial eagle, in danger of extinction, and the black stork.

The dehesa’s annual pastures are among the richest in the world in herbaceous plants: the Libro Verde speaks of more than seventy species per square metre. That is a density, not a total, and it is what makes it remarkable.

On wildfire, the mechanism is recognised by the public authorities. Since 2005 the regional government of Andalusia has run a network of firebreaks maintained by livestock: by grazing, the animals reduce the fuel load and create discontinuities that slow the spread of fire. The scheme covers wooded areas well beyond the dehesa alone, but the principle is the same.

One last point, since you often read that the dehesa’s oaks are thousands of years old: the cork oak lives around a hundred and seventy years, and can be stripped some fifteen times in its life. That is already long on the scale of a farm.

Its real protection status

The dehesa is a habitat of Community interest under the Habitats Directive, code 6310, "dehesas with evergreen Quercus". Spain holds more than three quarters of it, Portugal a sixth. That is European protection, binding on member states.

It is also at the heart of three biosphere reserves under the UNESCO MAB programme: Dehesas de Sierra Morena, designated in 2002 over 424,400 hectares and the largest reserve in Spain, Monfragüe in 2003, and La Siberia in 2019.

One thing the official reports mention less readily should be added: the conservation status of this habitat is assessed as unfavourable and deteriorating in the Mediterranean region. The ageing of the trees, the lack of regeneration and the disease pressure on the oaks are all documented. An acorn-fed ham depends on an environment that is faring worse than the story suggests.