Mob grazing can improve pasture productivity
Mob grazing is a term used to described a system where stock are kept at far higher densities than normal but moved on more quickly – usually at intervals of anything from 12 hours up to a maximum of about a week, during periods of slow growth. It has been used very successfully with beef, sheep, goats, pigs and fowl, and in orchards as well as open pasture.
Though the size of the “mob” may not vary greatly from conventionally managed stock, the animals are put out on much smaller grazing areas – the overall effect mimicking the behaviour of wild herds under threat from predators. Where possible herds are combined, the resulting increase in the number of available paddocks facilitating the extension of rest periods for the pasture in each one.
Benefits of mob grazing
Plants respond to the stress of overgrazing with reduced root growth, eventually leading to a deterioration in soil health as well as productivity. Although one might be concerned about mob grazing increasing overgrazing, the reverse is in fact the case as the mob grazes more evenly and once only; there being insufficient time for short-term regrowth, the grazing of which is responsible for stunting root development and hence limiting long-term productivity.
Reduced time spent in each pasture also minimises damage due to trampling. Longer recovery enables more luscious interim growth, which in turn favours more diverse swards particularly including more forbs, as well as increasing.
Forbs tend to be far deeper rooting than grasses, which further supports healthy soil structures as well as improved mineral cycling. They also have different nutritional qualities, many of which are particularly supportive to animal health. Increased litter supports improved soil structure by providing more organic matter for incorporation into the soil.
The resulting improvement in soil structure and health, as well as health of the sward and increased litter, reduces erosion and improves water utilisation, drainage and storage; a healthier root structure improves drainage as well as aeration, and also leads to increases in soil organic matter.
Although this method does require more planning than conventional methods as well as the infrastructure to enable these regular moves, farmers around the world have found that the initial effort to establish the system has been rewarded with improved productivity as well as healthier stock which can be kept outdoors for much more of the winter; soil structure being better and sward being more stable also reduces the impact of trampling damage as well there being more fodder available during the lean times, providing sufficient planning has taken place.
There may be an initial decline in output, which could be considered a transition period, but thereafter, it is generally found that fewer supplements are required and much less additional forage, which in turn can free-up for grazing some of the paddocks previously used for hay/silage/arable. Machinery costs can decline, too; for instance one farmer who has been using this system in the north of England finds he only has use for one tractor where he previously used three, and with increasing oil prices this is particularly relevant to the bottom line.
Those already using the system have often revised their choice of breed to account for the increased walking involved and also wanting lighter beasts better suited to outwintering, but this is usually compensated for by increased numbers as well as improved condition, resulting in better prices at market/better meat – as well as the reduced costs.