Mob grazing

Christine Page

There’s an old saying, “Never leave the sheep in the same field long enough to hear the church bell ring twice”. In other words, move them every week. 

Mob grazing is a modern version of this successful traditional farming practice and is one of the numerous sustainable farming methods we've introduced at Smiling Tree.

Using grazing animals to manage and encourage grass growth was common practice until the post-war industrialisation of agriculture saw thousands of miles of hedgerows removed and fields made bigger. It was replaced with artificial growth stimulants in the form of chemical fertilizers and ‘set stocking’, where a ‘set’ number of animals is left in a field for a long period of time, sometimes all year. To appreciate the significant consequences of set stocking and the use of chemical fertilisers you need to know a little about soil science.

Domesticated cattle and sheep still retain the instincts of prey animals, which in the wild would move regularly as a bunched group to find fresh grazing and keep predators at a distance. ‘Mob grazing’ replicates this natural behaviour by grazing animals in relatively small areas for short periods. Moved to fresh pasture every day or so, they don’t return to the same grazing area for weeks or even months. Grazing grass in this way, as the old farmers knew, benefits not only the animals but also the health of the land, the wildlife and the wider ecosystem.  

Benefits of mob grazing

  • Mob grazing paddocks typically grow tall plants due to the long rest periods between grazing. Moved on after a short period, cattle (or sheep) leave behind between a third and half the forage*, so the pasture is never grazed hard enough to lead to the issues associated with set stocking and, left with a large surface area of ‘solar panels’, the plants are able to re-grow more quickly.
  • When grazing animals are moved as a group (a mob) to a relatively small paddock of fresh pasture they instinctively become competitive for the available forage. They eagerly put their heads down and chomp whatever is in front of them, moving slowly and rhythmically across the paddock. They graze more evenly and less selectively and because the pasture has not been over grazed it retains diversity and interest for the animals. 
  • Mob grazing encourages beneficial trampling that doesn’t take place for long enough to lead to compaction. Where trampled and put in contact with the soil, the forage covers the soil surface, protecting it from erosion and dehydration. It also protects the soil from being cut up by the feet of stock, even during heavy rain. As broken stems decompose, they feed the soil microbiology, increasing soil health by creating organic matter, building top soil and enhancing water retention, which also helps to alleviate flooding.
  • Drought tolerance - the amount of cover left on the surface not only protects the soil from drying out but because the plants have experienced less severe grazing it allows them to grow deeper roots so they can draw moisture up from much deeper down, making them far more drought tolerant too. 
  • Even manure distribution – as the animals graze their way across the paddock they distribute their manure evenly, compared to a set-stocked field where animals often return to a preferred ‘campsite’ to sleep and dung.
  • Less compaction – animals do not have to walk far to search out their next juicy bite, so there is far less compaction from their feet. Also, as mob grazing areas are much smaller than those used for set stocking, their management need not involve driving and risking compaction from farm vehicles.
  • Plant resilience & season extension – areas of pasture used for mob grazing grow more robust plants due to the longer recovery periods during which they are not grazed. This leads to increased plant density and deeper more resilient root systems, which enable them to find water during the summer dry periods, and cope with ’flash’ grazing early and late in the season, all of which extends the period for which they can be grazed.
  • The faster recovery and greater density of plants means the land is more productive also and is able to support more animals leadings to increased stocking capacity.  
  • Increased animal performance – a healthy soil with good biology makes more nutrients available to the plants. The plants have a higher nutritional content that helps animals to grow better. Taller grass also provides more fibre for the animal, which slows the transit and enables better utilisation of nutrients.
  • Mob grazing is beneficial to the wild flora and fauna too: grazing animals in a ‘mob’ means all the plants get nibbled and this leads to greater diversity in the plant species. At any one time less than 5% of the land is being grazed, which means 95% is left undisturbed for many weeks and sometimes months, giving the grasses and wildflowers a chance to flower and set seed; ground nesting birds to raise their broods; nectar to be produced for bees; habitat development for bugs, beetles and voles; and ideal hunting for owls. 
  • More time with the animals & better animal welfare – as you manage a mob grazing system, you see the animals up close every day without having to drive around a large field trying to find them. As they walk directly past to their new grazing area, you can watch them move and have a much better chance of spotting any that don’t look happy. Of course, they are nearly always very happy to see you because, more often than not, you are about to open the gate to let them through to their next delicious salad bar banquet!

Disadvantages of mob grazing

  • Considerable time to plan is needed or the land can be overgrazed and damaged if move periods or stocking density are not right – the importance of this planning stage should not be underestimated.
  • Time and cost of initial set up of paddocks. This can be done fairly quickly and cheaply using temporary electric fencing, or it can be extensive with replanting of old hedge lines and installing permanent fencing and drinking water
  • Mob grazing may give the impression that forage is wasted by being trampled or left until tall to graze. Getting over this conventional view can be quite challenging, although if you get the first point right, you'll soon see the benefits.
  • Modern animals may not be best suited to mob grazing. You may need to change your breeding programme to Traditional breeds that are deeper bodied cattle. Those that are two-thirds body and one-third leg have deep bodies and plenty of rumen space to better utilise the taller forage.

We run courses on how to successfully implement mob grazing, improve pasture productivity and sequester carbon. Find out more on our courses page

 

Note: * Forage refers to food for grazing animals that they typically forage for themselves in fields or hedgerows, such as grasses, clovers, wild flowers, herbs and so on. Fodder, on the other hand, is typically what animals are fed during the winter months that has more than likely been conserved from the summer, such as hay or straw.