Combining livestock species can allow more complete use of the resources available on a holding. Cattle, sheep and goats do not graze in the same way or select vegetation with the same precision. The LIFE ScrubsNet protocol recommends taking these differences into account when organising mixed grazing, whether animals graze together or successively.
A dehesa contains food resources at different heights and in different forms: tall and short herbaceous pasture, tender shoots, woody plants, shrubs and fruit.
Likewise, each livestock species uses these resources differently. The LIFE ScrubsNet document explains that herbivore species graze in different ways and can consequently favour different plant communities and help shape the landscape.
These differences form the basis of mixed grazing.
What is mixed grazing?
The protocol defines mixed grazing as the simultaneous or successive combination of different livestock species, and even breeds, in order to make fuller use of pasture resources.
Rather than expecting a single species to use all vegetation uniformly, mixed grazing takes advantage of the different feeding preferences and abilities of each animal.
The document notes that grazing different species together can be particularly useful on large holdings or paddocks with abundant shrub vegetation.
Cattle: generally less selective
Cattle generally have a low selective and browsing capacity and tend to make greater use of taller herbaceous vegetation.
The protocol explains that cattle are generally less inclined to browse because their mouths are not particularly adapted to this feeding behaviour. At low stocking rates, cattle grazing may therefore allow woody plants to develop.
There are important breed differences, however. Native breeds such as Pajuna and Berrenda can be much better adapted to rough terrain dominated by shrub vegetation.
Sheep: greater selection
Sheep have an intermediate capacity for selective grazing and browsing and are able to use shorter vegetation than cattle.
Breed also matters. The protocol notes that Merino sheep and related breeds are generally less inclined to browse, whereas breeds such as Segureña may behave as effective browsers.
Management and the animals’ previous grazing experience therefore also influence how vegetation is used.
Goats: specialised browsers
Goats are particularly important where shrub vegetation forms part of the available forage.
The document describes goats as the browsing species par excellence, especially some native meat breeds.
Their high selective capacity allows them to choose shoots, leaves and other parts of shrubs very precisely.
This can be useful where scrub is intended to provide forage, but grazing intensity needs careful control where young trees or regeneration areas must be protected.
Using the right sequence
When livestock species graze successively, their order can influence how efficiently vegetation is used.
The protocol explains that cattle are generally less selective and cut grass at a certain height, whereas sheep and goats can take small bites close to ground level and select small shrub shoots.
For this reason, it recommends as one option allowing cattle to graze first, followed by sheep and/or goats.
Different species can therefore use different layers and components of the vegetation in sequence.
What about Iberian pigs?
Iberian pigs have yet another feeding pattern.
During the montanera, the protocol notes that they concentrate on acorns and grass, giving them a different role from ruminants such as cattle, sheep and goats.
Combining species can therefore help distribute grazing pressure across different resources and periods of the year.
There is no universal combination
Mixed grazing is not simply a matter of placing several livestock species in the same paddock.
Behaviour varies according to species, breed, previous experience and herd management. The protocol emphasises that these factors ultimately influence whether livestock favour the development of woody vegetation or use it as a forage resource.
The appropriate combination must therefore reflect vegetation, livestock breeds, shrub cover, regeneration status, season, stocking rate and management objectives.
Different animals, different functions
The LIFE ScrubsNet message is clear: livestock diversity can itself become a management tool.
Cattle can make use of taller pasture first. Sheep can graze shorter vegetation with greater precision. Goats can make more intensive use of shrub shoots and leaves.
When properly combined, these different behaviours can make use of a wider range of available resources.
Mixed grazing does not mean that every animal eats the same thing. Its value lies precisely in the fact that they do not.
The LIFE ScrubsNet project is co-funded by the European Union through the LIFE programme, LIFE20 NAT/ES/000978.