Watching cattle or sheep in a field you might mistakenly think that grazing is a simple process; head down and off they go chomping through the pasture.

In reality, grazers can be just as choosy about what they eat as you or I.

Where possible animals prefer to choose what type of vegetation to focus on. While this may be an option for animals in large enclosures or on very varied vegetation, most farm animals are restricted to one pasture type by fencing. However, even in regular fields, grazers can still make choices as to which patches they focus on, and even which plants or plant parts they choose.

The National Wales: Mariecia Fraser is Professor of Upland Agroecology at Aberystwyth University and head of the University’s Pwllpeiran Upland Research CentreMariecia Fraser is Professor of Upland Agroecology at Aberystwyth University and head of the University’s Pwllpeiran Upland Research Centre

How selective their grazing becomes is largely dependent on how big they are. Larger animals such as cattle tend to prioritise quantity over quality of herbage consumed and will more quickly move onto less favoured vegetation. In contrast, smaller grazers such as sheep tend to be much more selective and will carry on picking out favoured plants despite these becoming scarce. This can lead to such plants becoming grazed out, and if the plants that are rejected are competitive these can take over and dominate the vegetation.

We see lots of examples of plants being grazed out on hill ground where more invasive species such as purple-moor grass or mat-grass have taken over. To be clear, this deterioration in habitat value is not the fault of any one kind of animal. Despite their bad press, sheep aren’t at the root of all biodiversity ills. The problem is that there is only one type of grazer grazing.

This is where the concept of ‘conservation grazing’ can come in handy.  This is defined as the targeted use of grazers to improve biodiversity and is a term that is most commonly used in relation to designated sites such as nature reserves. However, the approach can be used anywhere, and if adopted in a farming situation can lead to a double win of better biodiversity and improved use of pasture. Conservation grazing exploits the fact that all grazers are selective feeders.

READ MORE: The shepherd farming at one of Wales’ most popular tourist attractions

Within natural grazing systems different species of animal use the same area but target different vegetation resources within this. A simple farming equivalent is having cattle grazing with sheep, since these will quickly move on from selecting preferred but rare patches and plant species to graze vegetation rejected by sheep. This might be those invasive hill grasses, or it could be mature, stemmy material in a more typical field.

With the cattle and sheep grazing different elements, pasture is used more efficiently. The removal of rejected material also generates new, more nutritious, plant growth, which improves animal production. All this helps reduce the environmental footprint of livestock farming, while also increasing floristic diversity within native plant communities. Getting such habitats back into favourable condition in turn supports greater numbers and diversity of insects, birds and small mammals.

While research has shown all this is possible, large tracts of land across Wales require this type of intervention, and cattle numbers continue to decline. The restoration of diverse grassland habitats would be made quicker and more attainable if future support schemes prioritise the wider delivery of public goods, rather than primary production. Crucially this could allow the grazing outcomes of stock types other than sheep and cattle to be eligible.

Goats, alpacas and ponies will also readily consume stemmy material rejected by sheep and invasive hill grasses, as well as plants such as rushes that increasingly require controlling. Incorporating the keeping of these into farming systems could diversify income streams, and so help support rural livelihoods. Thus, mainstreaming conservation grazing offers a rare opportunity to simultaneously improve environmental, economic and social sustainability. By effectively making different kinds of animals eat at the same table, we could use their picky eating habits to strengthen our rural ecosystem.

Mariecia Fraser is Professor of Upland Agroecology at Aberystwyth University and head of the University’s Pwllpeiran Upland Research Centre.

If you value The National's journalism, help grow our team of reporters by becoming a subscriber.