For sustainable grassland management, farmers need to know whether they are farming with sweet or sour veld, and adapt their livestock management practices accordingly. Glenneis Kriel reports.
Rangeland management is one of the most limiting factors when it comes to extensive livestock production in terms of production per hectare and, in effect, per farm, resulting in poor fertility, calving and growth.
A study by the Agricultural Research Council (ARC) University of the Free State, for instance, found that calving percentages achieved in the South Africa is relatively low, averaging around 62% on commercial farms, 48% on emerging farms and 35% in communal areas.
“Improved and sustainable veld management could go a long way in increasing average calving percentages, which will improve farm margins, alleviate poverty and make South Africa less reliant on beef imports,” says Dr Mias van der Westhuizen, rangeland specialist of the Free State Department of Agriculture and Rural Development.
A livestock farmer’s first objective, therefore, should be to look after his veld and protect it against degradation, which will repay the service by looking after the livestock and the farmer. To start off the farmer needs to know what type of veld he is farming with.
Types of Veld
In the grassland biome, mainly found on the central plateau, include the Free State, and inland areas of KwaZulu-Natal and the Eastern Cape, differentiation is made between sweetveld, sourveld and mixed veld, based on the palatability of the veld. Palatability, in turn, is determined by climatic factors and soil quality.
Sourveld generally occurs in areas with poor acidic soils, rainfall above 650 mm and cold winters, such as the Highveld and high altitude areas of the Eastern Cape and KwaZulu-Natal.
“The high rainfall in these areas leaches away the minerals of the soil, leaving it with little nutrients to feed plants. Farmers with sourveld, in effect, may have high volumes of grass, but with poor palatability and nutritional value,” explains Van der Westhuizen.
Sweetveld occurs in areas with lower rainfall and milder winters, such as the central and western parts of the biome. The soils have a higher mineral status thanks to the lower rainfall, resulting in plants and grasses with a higher nutritional value and that are much more palatable than those found in the sourveld.
Mixed veld primarily occurs in areas of transition, where rainfall varies between 500 mm to 600 mm, with the sourveld growing in areas with acidic soils and the sweetveld on more alkaline soils.
Veld Management
The idea behind veld management is to create a sustainable grazing ecosystem, whereby veld is managed in a way that unlocks animal’s full production potential without this resulting in degradation or erosion.
Sourveld grazing is limited to its growth period in spring and summer, which depending on environmental factors can range from 5 to 7 months. With good management, sweetveld, in contrast, can be grazed throughout the year, without resulting in a drop in animal condition over winter.
Kirkman says that a lot of research has been done up until now to determine whether the use of fertiliser can help to improve the nutritional value and availability of sourveld, but no viable solution has been found up until now.
“Using fertilisers to try and manipulate sourveld is not only economically unfeasible, but trials so far have shown that the addition of certain chemicals, such as nitrogen, might actually disrupt the ecosystem, resulting in unpalatable species becoming more dominant.”
Managing sourveld, nevertheless, is relatively easy. Firstly, because it is less vulnerable to drought because of the high moisture content of the soil, and secondly because the chances of overgrazing are so low. As a matter of fact, chances are greater that sourveld might be under-grazed, which will result in the grasses becoming even more unpalatable.
“As a rule of thumb, if you use a beer can to measure it, the grass should never be higher than the can when it is placed upright on the ground, or lower than the can when it is placed on its side,” Kirkman says.
But what can be done if the grass has been left to grow too long? Dr Josef van Wyngaard, technical manager of Voermol Feeds, advises that farmers can regain control of this veld by putting high densities of cattle on it: “Sheep won’t work as they are selective eaters with a grazing height range of only 2 to 30 cm.”
Care should then be taken to address nutritional deficiencies that might emerge from the poorer quality of the veld, by supplying these cattle with additional protein licks. The palatability of the grass may also be increased by spraying it with molasses solution containing traces of urea and minerals, according to Van Wyngaard.
The management of sweetveld is trickier, as it is much more vulnerable to drought because of the variability in rainfall. Van der Westhuizen points out that dry matter production on sweetveld varies between 200 kg/ha during dry years and up to 1 600 kg/ha in around Boshof and Petrusburg, in the Sandveld parts of the Western Free State.
The carrying capacity is also lower, ranging between 6 ha/LSU to 30 ha/LSU in comparison with 4 ha/LSU to 6 ha/LSU on sourveld, according to Van der Westhuizen.
For optimal management, farmers need to know and understand the composition of species that grow under their production conditions and the way in which these are influenced by grazing and climatic conditions.
“You need to create a plan now, if you have not already done so, as good veld management can significantly lower your vulnerability to droughts and also accelerate the time it takes for veld to recover following a drought,” Van der Westhuizen says.
The plan should also be adapted continuously in accordance with veld and climatic conditions, to allow the recovery of areas where deterioration or degradation is observed.
A lot of research has been done on the composition of species in different areas. The goal with veld management would be to keep the climax species dominant.
“You know you have veld problems when climax species, such as red grass, finger grass and wool grass are replaced by less palatable grasses, such as wire grass, or grasses that are less productive, such ass as Lehmann’s love grass and curly leaf,” Van der Westhuizen says.
Further deterioration will result if these plants are taken over by pioneer species, such as stick grass and coach grass. When this happens, the grazing capacity of the veld will decline tremendously, while the risks of droughts will increase and the advantage of high quality sweetveld will be lost. This, in turn, will result in higher input costs, and livestock would have to be supplied with more additional feed to prevent nutritional imbalances, according to Van der Westhuizen.
From a management perspective, the biggest causes of problems are overgrazing and the veld not getting enough time to rest. Continuous use of the same camp for calving or lambing each year should also be avoided. “It is understandable that farmers might want to single out certain camps for specific reasons, but the ideal is for camps to be rotated and used during different climatic seasons,” Van der Westhuizen says.
There is a lot of talk about the benefits of ultra-high density grazing, where high numbers of stock are left to graze the veld over very short periods.
But, Van der Westhuizen says that scientific data is currently still insufficient to proof that ultra-high density grazing is more advantageous for veld in the long run, than well-managed veld rotation system.
“Current research on well-managed veld rotation systems proof these systems result in improved veld conditions, decreased risks of droughts and increases livestock production, increasing the profitability of farming units. These long-term trials are executed on different sweet veld vegetation types, ranging from the Kalahari dune veld in the west to the red grass veld of the central Free State,” says Van der Westhuizen.
For example, the results of one of these trials on the Glen research farm, showed a significant improvement in calving percentages and weaning weight, increasing farm income per cow from R1498, with no veld management interventions, to R5472 in just four years following the introduction of a well-managed rotation system.
Calving percentages of up to 92% were achieved, without receiving any production or protein licks, only salt supplements. Heifers were mated as early as fourteen to sixteen months, and production was significantly better during times of drought with an effective veld rotation system, than in the absence of a rotation system during normal seasons.
Farm planning is also important and depending on the vegetation type and topography camp sizes of less than 100 ha is usually manageable if it doesn’t include different veld types. In the trial at Glen research farm, nine camps were allocated per herd and camp sizes varied from 20 ha to 96 ha.
“The good news is that farmers don’t have to divide their camps to sizes of 5 to 10 ha to be sustainable,” Van der Westhuizen says.
Feed Supplements
Protein supplements are non-negotiable on sourveld for six to 7 months of the year, as the veld from Autumn to Spring generally does not contain enough nutrients to maintain body condition in livestock. In some conditions, sourveld only supply enough nutrients for three months of the year.
“The situation is so dire that you need to use urea, which is a synthetic source of nitrogen, in combination with natural sources of protein, such as oilcake, since urea can only be utilised by the microbes in the rumen. These microbes become a source of protein for the animal, but is not sufficient on its own to adhere to the animal’s protein requirement during maintenance on sourveld during winter, hence the additional natural protein requirement” Van Wyngaard says.
Phosphate supplements are also important, but even more so in some sweetveld regions. “While soil quality is generally better on sweetveld than sourveld, some are depleted of phosphates that then has to be supplemented to the animals to avoid reproduction and growth failure,” Van Wyngaard says.
Supplement intake need to be managed carefully with cattle on both sweet- and sourveld. “On sourveld, the cattle tend to eat too much supplement because of the poor palatability of the veld. This is addressed by raising the salt percentage of the supplement to roughly 40 percent,” Van Wyngaard says.
Cattle on sweetveld, however, might not eat enough supplement. The salt content of their licks should, therefore, range between 10% to 25%.
Molasses is generally used as an energy source, but also helps to improve the palatability of the supplements. It also contains high levels of potassium, which is important for both cattle on sour and sweetveld.
“Protein deficiencies will manifest in the form of clumpy, hard and dry manure. Potassium works like a light laxative, helping to keep the digestive system moving which ensures a rumen environment for optimal microbial fibre digestion” Van Wyngaard says.
The quality and type of veld will also influence the feed composition and regime, which can be divided into four phases: Summer supplementation, which starts after the first rain, from November to February; Transition supplementation, when the veld starts to deteriorate from February up unto April; Winter supplementation, following the first frost in April up until August; and supplements for the calving season, August/September to October.
Van Wyngaard identifies phosphates and trace elements as the major nutritional priorities in summer: Cattle need a minimum of 6g of phosphates per day during these times, depending on veld conditions.
Vitamin A supplements are also important, since dry grass does not contain any vitamin A. “Vitamin A is important for healthy mucous membranes, immune function, fertility and deficiencies may lead to increased risk for infectious diseases and reproductive failure,” says Van Wyngaard.
During the transition period, cattle generally need a protein phosphate combination, requiring roughly 50g to 80g of protein and 6g to 9g of phosphates per day depending on veld conditions.
The protein demand will increase to between 180g to 240g on sourveld, when this veld goes dormant from April to August, whereas the phosphate demand will fluctuate between 2 to 6g. Trace elements and minerals will also be important during this stage to prevent nutritional deficiencies.
During the calving season, supplements should become more energy focussed to ensure the cows have enough energy for uncomplicated birth, milk production to sustain optimal growth of their calves, and fertility for the following calving cycle.
Supplemental intake is at its highest at this point of the production cycle, ranging between 1 kg to 1,5 kg per day compared to 400 to 600 g for a protein lick, 200 g to 300 g for a transition lick, and 100 to 200g for a mineral lick, according to Van Wyngaard.
Creating a feeding regime is nevertheless easier said than done. Van Wyngaard says that the best is to get the advice of a feed consultant, to help you develop supplement rations based on the nutritional value of your veld and the nutritional demands of your cattle during different stages of production.
An example of a sustainable camp rotation system with huge benefits
The inclusion of a complete rest season for at least one out of three or four growing seasons is essential for sweetveld types, according to Dr Mias van der Westhuizen.
He uses the following example of a 3-block system that was specifically developed for beef cattle in red grass sweet vegetation types, but can also be used in the mixed, sourgrass, sweetgrass as well as the False Karoo: All camps on a farm are divided into three basic units of the same potential or veld preference communities (A, B and C; see Figure 2).
One unit is then grazed in rotation with all livestock on the farm within the months specified. The overall aim of the system is to apply a long seasonal rest immediately after non selective grazing (high intensity grazing where palatable and even unpalatable species are grazed) followed by a controlled selective grazing (palatable species not overgrazed), followed by a light controlled selective grazing after which the system repeats itself.
The first group of camps is used at high density for seven months in June to December, and then left to recover for thirteen months.
The second group is strategically reserved for low intensity grazing around January, to improve livestock productivity during the mating and calving season.
“This group, which was the normal intensity grazing group from the previous year, is considered a grazing reserve that will only be grazed lightly, unless there is a very poor growth rate that year drought, in which case it is an indispensable fodder reserve. Animals can be moved to this group as early as November to alleviate pressure on other camps during times of drought,” Van der Westhuizen says.
The third group of camps is grazed at a lower intensity. Cattle are moved to this group during the mating season in February to ensure high performance and remains there until May.
The system is rotated, resulting in the high intensity or first group being used as the third group after a recovery period of 13 months, and the third group, after resting for 6 months, taking the place of the second group, for strategic low intensity grazing. The second group of camps then replace the high density grazing camps. (See diagram for more information.)
“Grazing intensity and the recovery period is varied to get the maximum veld improvement,” Van der Westhuizen says.
Different grazing programmes would be required for sheep and cattle in Savannah and Karroid vegetation types, different grazing systems would be recommended.
Diagram1: The rotation system at the Glen research farm.
Camps are divided into three groups (A,B and C), with grazing then rotated on then over the year.
| Year | Jun, Jul, Aug, Sep, Oct, Nov, Dec | Jan | Feb, Mrt, Apr, May |
| 1 | AB | B | C |
| 2 | BC | C | A |
| 3 | CA | A | B |
