Our familiar rural landscape has not occurred by accident. It has evolved over thousands of years of management by farmers and land managers. Grazing is a natural process of exchange.

The animals live and feed on the land, the flora and fauna dependent on grassland are maintained and we feed and clothe ourselves with the products.

Due to a range of pressures on the land through economic development and increased food production, the traditional landscape, with its attendant ‘natural’ grassland habitats and species has been lost from large parts of the country.

In the Mendip Hills, the remaining rare species-rich grasslands need to be managed appropriately to ensure their survival. Along with scrub clearance and control of invasive plants, grazing is the main method of achieving this goal. An efficient grazing regime is based on a complex combination of four factors:

• Timing - time of year and frequency of grazing
• Intensity - stocking rates
• Targeting - which areas to graze
• Stock - type of animal used

Cattle prefer to eat longer grasses and use their tongue to pull and tear the vegetation, grazing to a minimum height of 5-6 cm. Cattle are generally better than sheep at creating and maintaining structurally diverse grassland:

• their large size and heavy weight breaks up the ground
• they avoid grazing around dung pats which creates patches of longer vegetation important for insect communities. These in turn are eaten by birds and bats
• cattle are particularly good at knocking down and creating gaps in tall, coarse vegetation such as bracken and scrub

Different cattle breeds have differing effects on rough grassland. Traditional breeds are more adapt at eating rough grassland and putting on weight and condition for production compared to commercial breeds. Cattle need more water than sheep and their grazing coverage can be influenced by the number and location of water troughs.

Mineral licks can draw cattle into poorly grazed areas. Poaching - the excessive trampling of areas by cattle, particularly when wet - adversely affects pasture and can lead to a hard impenetrable surface when dry, where plants can’t germinate.

It is a particular problem that can occur when cattle are over-wintered outside and around water troughs and feeders.

Sheep have thin, mobile lips and move slowly over the sward nibbling the grass. They eat selectively when circumstances allow, biting off single leaves or shoots down to a height of 3cm. It is notable that sheep only develop a full set of adult teeth after 3-4 years and then steadily lose them as they age, therefore young and old sheep may not graze as efficiently as middle-aged sheep.

As well as grasses and herbs, sheep will also eat low scrub, especially hardy breeds such as Soay and Hebridean, and can completely remove leaf material from selected bushes.

The benefits of grazing with sheep are:

• they are light and more agile than cattle and are more suited to steeply sloping land
• on heavy, wet soils sheep will cause beneficial trampling and poaching, but are not as impactful as heavier grazers
• their dung is deposited randomly and they will graze next to it and so will graze swards to a uniformly low height

Sheep will not tackle long grass or scrub, but are less susceptible to the toxins in ragwort. They can be used to spring graze ragwort in its rosette stage to prevent flowering and setting seed.

However, sheep are not immune to its toxins so require plenty of other vegetation to eat along with it. Extensive bramble can cause difficulties for sheep as their fleece may get caught.

Sheep are prone to foot rot so may not be best suited to predominately wet sites. Sheep require more secure fencing than cattle which can be costly.

Horses and ponies have forward pointing teeth and can graze extremely close to the ground - as close as rabbits. The benefits of grazing with horses and ponies are:

• they preferentially select grass, but also eat a variety of sedges and rushes
• they tend not to select flowers, as sheep do, and avoid buttercup, knapweed and ragwort, but readily graze tor grass, a species that can take over limestone grasslands
• these ‘fussy’ diets are ideal for maintaining the mosaic habitat needed by many insects.

As with sheep and cattle, there are behavioural and grazing differences between horse breeds. Native breeds such as Exmoor, Dartmoor and New Forest ponies are regarded as more suitable for rough grassland.

Problems can arise in smaller areas, as horses create latrines which can cause localised high nutrient levels and encourage the spread of thistles, nettles and docks.

Regular collection of dung will alleviate this problem. In an ideal world, a combination of all 3 species will produce a perfectly managed site.

All grazing animals need:

• water – via a trough, man made channel or naturally occurring
• shelter – against the worst winter weather or shade in the summer
• fencing – appropriate and well maintained
• attention – daily checking
• care – on site or off site visits by a vet may be necessary.