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- One of the most common misconceptions among grazing managers is that allowing animals to graze grass regrowth is harmful.
- Linked to this misconception is that ultra-high-density (UHD) grazing accurately mimics the natural behaviour of large wildlife herds.
- Wild herds constantly seek out immature, nutrient-rich grass. By delaying their return for months, they miss the most nutritious stage of the grazing cycle.
- Dr Fynn also advocates the split-ranch system.
- He explained that resting the veld for an entire year is crucial because soil microbes release nitrogen into the soil early in the growing season.
One of the most common misconceptions among grazing managers is that allowing animals to graze grass regrowth is harmful, says Richard Fynn, professor of Rangeland Science at the Okavango Research Institute, University of Botswana.
This approach suggests that animals should take only a single bite from each blade of grass before moving on. The belief is that a second bite will damage the grass and ultimately lead to veld degradation. Based on this view, animals should only return to a specific tuft after a long rest period.
Differences in grassland types
Speaking at the 2025 congress of the Grassland Society of Southern Africa, Dr Fynn noted that this perspective fails to account for differences in grassland types.
“In arid regions, where grasses grow slowly and mature grasses retain much of their nutritional value, restricting animals from grazing regrowth has a limited impact on animal production. However, in mesic areas with annual rainfall exceeding 600mm, grasses grow more rapidly, and quality declines significantly as they mature. Forcing animals to feed only on long-rested, mature grass in these areas can harm production,” he explained.
Ultra-high-density grazing
Linked to this misconception is the commonly held belief that ultra-high-density (UHD) grazing – with very short grazing periods and extremely long rest periods – accurately mimics the natural behaviour of large wildlife herds. “In reality, herds move into areas with young, green grass, such as recently burnt patches, a few weeks after good rains. They graze the area down and move on, returning after several weeks when the grass has regrown to provide fresh, highly nutritious regrowth.”
Extensive evidence from studies (e.g. in the Serengeti and elsewhere in Southern Africa) shows that herds frequently return to the same area throughout the wet season. Research on buffalo in the Kruger National Park indicates that they revisit specific sites approximately every ten days. This differs from the holistic approach.
Wild herds constantly seek out immature, nutrient-rich grass. By delaying their return for months, they miss the most nutritious stage of the grazing cycle. In nature, animals only consume mature grass if rainfall is insufficient. “Wild herds have a natural system that adapts to rainfall variability, and we can replicate this on our rangelands,” Dr Fynn explained.
Facilitating natural grazing
To mimic natural grazing on a cattle farm, management must account for three distinct grassland structural states under high-density grazing – a method he terms a facilitative recursive grazing strategy (Figure 1). “The first is the short grass area (priority paddocks), which cattle return to as soon as regrowth is adequate. The second comprises mature grass reserves, grazed only if rainfall is poor and priority paddocks haven’t recovered. The third includes areas rested for a full growing season, serving as grazing during the dry or winter season.” This approach better reflects how wildlife naturally moves across a landscape, compared to the holistic method.
Figure 1: A visual illustration of the facilitative recursive grazing strategy.
Dr Fynn also advocates the split-ranch system, where half the farm is rested for an entire growing season while the other half is grazed intensively. For instance, on a farm with 12 paddocks, six are grazed while six are rested, with the grazing/rest cycle running from August to August.
“The challenge with the holistic approach isn’t the long rest period itself, which is essential. The problem arises when animal performance is compromised because they are only offered mature, low-quality grazing during extended rest periods. This can be mitigated by altering the way cattle are moved,” he explained.
This strategy is built on three key pillars: non-selective, high-density grazing, a full season’s rest every second year, and the use of fire in high-rainfall areas during spring to encourage non-selective grazing.
In the taller grass scenario (photograph 1), Sam McNaughton found that protein content was 10,8%. After the grass was grazed down (photograph 2) and fresh regrowth was stimulated (a process known as facilitation), the new growth contained 15,7% protein. This explains why wildebeest and zebra often return to areas grazed a few weeks earlier, taking advantage of the nutrient-rich regrowth in what is called a recursive grazing strategy. (Photographs: T Michael Anderson)
Grazing cycle in practice
In practice, paddocks are burned shortly after the first rain. Grazing begins once the grass reaches the height of an upright beer can, using high-density stocking. When the grass is reduced to the length of a beer can lying on its side, the cattle are moved to the next paddock.
This rotation continues until the grass in the first paddock has regrown to the height of an upright beer, at which point grazing returns to that paddock and continues through the others, depending on regrowth and rainfall. Priority is always given to paddocks with the best regrowth but if regrowth is insufficient due to dry conditions, cattle are moved to reserve paddocks with mature grass.
In years of good rainfall, only some priority paddocks may be needed, allowing others to rest for more than a year. In dry years, all priority and reserve paddocks may be used. The system is flexible and adaptive.
As each new grazing cycle begins in August, cattle will probably be required to graze dry, mature grass until the rains arrive. If the veld has not been sufficiently trampled, priority paddocks are burned after the first rain to make previously unpalatable grasses suitable for grazing. High-density grazing then begins. By returning to paddocks only once they have adequately recovered, sufficient winter grazing can be preserved in unused camps, sustaining the herd until the next grazing cycle starts in August on the other half of the farm.
Importance of resting the veld
He explained that resting the veld for an entire year is crucial because soil microbes release nitrogen into the soil early in the growing season, right after the first rains. This means nitrogen is most available to plants during this period.
“By resting your veld over November and December, when nitrogen availability peaks, plants can replenish the nitrogen lost during the previous year’s grazing. However, for nitrogen to be stored in roots through the dry season, resting must continue into the early dry season to cover the period of maximum root growth at the end of the growing season. Grazing too early disrupts nutrient translocation to the roots, causing nitrogen that could have been stored there to be lost.
“When plants are allowed to complete their full growth cycle, which may extend to June or July, they emerge in the next season much more productive and resilient to drought.”
Adapting strategies
He recommended that producers in high-rainfall areas get all grasses in priority paddocks – both palatable and unpalatable – down to ground level at the start of grazing, which often requires fire. In semi-arid areas, high-density grazing combined with trampling between August and the first rains can level paddocks and create a protective litter layer on the soil.
Most grass species are relatively palatable when producing new shoots. By applying a sufficiently high grazing density, selective grazing can be largely avoided – this is a crucial point. If the grazing cycle does not commence when the grass is uniformly short and young, the less palatable grasses will gain an advantage, monopolising below-ground space with their roots. This is why selective grazing can be so harmful.
In contrast, non-selective grazing benefits the palatable grasses, which are better adapted to frequent grazing. Under these conditions, palatable grasses grow more quickly than unpalatable ones, gradually displacing them.
The conclusion is that this grazing management approach offers an effective balance between animal production and veld regeneration. – Izak Hofmeyr, Plaas Media
Send an email to Dr Richard Fynn at rfynn@ub.ac.bw for more information.
