SUSTAINABLE NATURAL RESOURCE UTILISATION
Ruminant livestock production is largely based on natural resources (veld), which poses restrictions on the competitiveness of this large and important livestock sector. A full understanding of the dynamics of and interaction between rangeland (veld), pastures, climate and livestock is essential for sustainable livestock farming. Therefore, whether livestock production is based on rangeland in an ideal condition or a poor condition, it is dependent on net forage production.
Support services directed at sustainable rangeland utilisation and management are at present very fragmented. The research and development (R&D) functions and responsibilities are spread among the nine provincial departments of agriculture, the national department of agriculture, ARC, universities, the CSIR, SAEON, Conservation SA, and SANBI. It is clear that biomes and zones of homogenous agricultural potential are spread across provincial boundaries and for R&D to succeed and to eliminate duplication, it is essential that projects should be carried out across provincial boundaries.
Furthermore, there is inefficient communication between research and development organisations. Similarly, communication with the producers’ organisations, i.e. RPO, NWGA and SAMGA, is not effective. The present fragmentation within the research community weakens the effectiveness of research as well as extension and technology transfer efforts. Excellent infrastructure is available to serve the livestock producers within the different biomes, but what is lacking is a national focus across provincial boundaries.
The complexity of solving a comprehensive problem such as vegetation deterioration warrants the inputs of various researchers and expertise in all the relevant sub-disciplines of plant, animal and social sciences. The mere fact that rangeland degradation is still impeding sustainable livestock production, in spite of the number of investigations, indicates that research organisations within livestock do not take the problem seriously, or they are not prepared to or unable to put proper prioritisation mechanisms in place when they decide on priorities.
Assessing the condition of plant communities is a convenient way of comparison, which also provides a way to quantify and observe spatial and temporal changes within a particular community or vegetation type. While man has little control over the influence of climate and soils on the structure and composition of vegetation, defoliation because of fire and grazing/browsing will influence the dynamics of any plant community. Management of any plant community should be governed by knowledge of its present condition relative to its “ideal” condition in a given environment.
In the present context, the term “rangeland condition” is used to describe vegetation in relation to its long-term potential for livestock production. It is defined as the “state of health of the rangeland in terms of its ecological status, resistance to soil erosion and its potential for producing forage for sustained optimum livestock production”. Soil loss may be regarded as an absolute measure of “health” of grazing lands since it is irreversible – except over extremely long periods of time – and it causes reduced productivity and affects future land use options. Vegetation is used to quantify rangeland condition since it is a more sensitive indicator of ecosystem change and is easier to measure than soil. Describing the condition of a sample of rangeland is meaningful only if it is related to some known standard, or when monitored over time, but is complicated because vegetation varies greatly with environmental conditions. Analysing the variation in vegetation composition and rangeland condition across environmental gradients, can reveal important vegetation and environmental interactions.
The aim of rangeland and herd management is to ensure the optimum energy supply to the animal without degrading the ecosystem. However, in reality many rangelands have been degraded. This includes all biomes, which among others, have been seriously eroded by desertification, bush encroachment and the loss of acceptable plant species. The problem of degradation and the impact on present and future livestock production is by no means new and over the period, commencing with the investigation of the Drought Commission in 1923, much was said and written about rangeland deterioration. However, it is sad to note that many attempts to halt the deterioration have failed, which is of serious concern when considering a livestock strategy. Should this deterioration be allowed to continue, sustainable livestock production would be jeopardised.
Since 71% of the land available for agricultural is suitable only for animal husbandry activities, livestock production is primarily dependent on natural resources, which means that the livestock sector has a prime responsibility to use this valuable but vulnerable natural resource sustainably. History shows that the livestock sector, research institutions, policy makers, and livestock farmers in general have a poor understanding of this concept. Continuing deterioration of the natural vegetation is currently one of the most burning issues in southern Africa, having a negative impact on the competitiveness and efficiency of the livestock sector. It is therefore imperative that role players within the livestock sector (research institutions, national and provincial government departments, livestock farmers as well as the related secondary industries) must recognise that the natural resource is vital to sustain livestock production and that they commit themselves to implement the necessary proposed recommendations.
RANGELAND AND HERD MANAGEMENT
Many of the important management decisions a livestock farmer makes relate to the management of the forage resources of the land unit. Both biological and economic efficiency is influenced by a farmer’s ability to match animal type and their nutritional requirements to availability and quality of forage on a year-round basis. Animal type as defined primarily through species and breed differences has a considerable influence on the nutritional requirements of animals. Therefore, the type of animal can have an impact on its level of performance and on economic returns of a grazing system, for different rangeland types/forages. The grazing/browsing system affects the intake and quality of forage, and therefore influences the nutritional status of feed available to animals. Intake decreases when rangeland is grazed too short. Regrowth of the vegetation is slower because the leaf area for photosynthesis is decreased and the quality of the forage is lower.
Management choices about forage and grazing systems should consider farmer decisions, such as timing of parturition to match the lactation curve of females to the forage production curve or choosing to graze castrates (steers or withers) rather than breeding females and their offspring. The nutritional requirements of the grazing animals also determine the choices of forage, and should be considered over a period of 365 days when determining the percentage of forage (fodder-flow) used in the grazing system. Grazing different species at appropriate ratios together can increase efficiency of forage utilisation because of differences in behaviour and forage/browse preferences.
A further aim of rangeland and livestock management is to ensure the optimum quantity and quality forage per mm rainfall, which would contribute to optimum livestock production without degrading the ecosystem. Rangelands have deteriorated considerably, as mentioned above, but the challenge is to reverse the situation and to ensure that rangelands improve through sound rangeland and livestock management systems. Evidence indicates that it is possible to implement a rangeland improvement scheme that will ensure long-term economic stability for the pastoralist. The challenge is to change the mind-set of the pastoralist, researchers within the domain of livestock research, and extension advisors and policy makers. They have to accept and give recognition to the importance of the natural resource (vegetation) as the driving force of sustainable and economic livestock production systems.
In the context of the aforementioned, efficient livestock production depend on:
- The absorption and photosynthetic conversion of sun (solar) energy to chemical energy (organic compounds) by plants (the better the condition of the vegetation the more efficient the process and therefore the more sustainable and economically viable livestock systems will be); and
- The efficient absorption of chemical energy (organic compounds) by the livestock (influenced by the health, type and genotype of the animal for a specific area) from the plants and the conversion to meat, milk or fibre.
The grassland ecosystem in a rapidly changing environment, as well as global change towards a generally hotter, drier, more variable and risk-prone environment in South Africa, is a scenario that must be taken seriously in the application of grassland management principles, to ensure long-term productivity and profitability of production systems at the lowest risk. The ecologically sensitive arid and semi-arid regions require specialised expertise in effective rainfall utilisation.
To attain this, the following should be defined for the different ecological regions:
- The amount of fodder produced per mm rainfall under different rangeland conditions
- The nutritional value of the fodder produced under different rangeland conditions and seasonal variability
- The availability of the fodder produced to the grazing/browsing animal under various management regimes and how it fluctuates
- The biological impact of animal type, numbers and distribution on the functioning of ecosystems under different degrees of degradation
MATCHING SPECIES, BREEDS AND COMBINATIONS WITH THE PRODUCTION ENVIRONMENT
Unsatisfactory attention has been given to the factors that influence the regionalisation of livestock and livestock production in South Africa, despite a detailed study which was carried out in the 1950’s and the information being available at the department of agriculture. Matching livestock to both the environment and the production system is a key challenge in sustainable livestock agriculture, and by integrating information on the production environment with information on species and breeds, livestock farmers will be able to make a more informed choice as to the breed and combination best suited to individual production inputs.
The challenge is not to change the vegetation to suit a specific animal type or production system, but to use the animal type and production systems as determined by the environment. Given the large variation in rainfall and the consequent impact on grazing capacity, the challenge is to exploit this variability and to develop sustainable livestock production systems for the different ecological regions. If the environment (especially rainfall) is analysed, some current livestock production systems within specific regions remains questionable. This relates especially to commercial livestock farming in areas that are not according to recommendations and the requirements of the vegetation.
The pastoralist can employ livestock types or a particular mix of species to achieve specific objectives, e.g. goats to control bush encroachment. Management tools (e.g. fire) can also be employed to manipulate the vegetation to make their structure more suitable for particular livestock.
THE POTENTIAL ROLE OF PASTURES IN DIFFERENT TYPES OF RANGELAND
The major role of cultivated pastures in farming systems is to satisfy the nutritional requirements of livestock during periods when the quantity and/or quality of forage produced by rangelands are inadequate. Their primary role should be to provide forage during the periods of food shortage in the fodder flow programme; and increase the total amount of forage and digestible nutrients produced on the property.
The role of cultivated pastures will depend on the nature of the livestock production system and the quality and quantity of forage that is available. The role, therefore, will be a function of the rangeland type.
In sour veld, cultivated pastures can:
- Increase the length of the growing season, particularly in the spring and autumn periods
- Increase the total amount and quality of forage produced on a property
- Provide high-quality green forage during the winter months (particularly for the dairy industry, using irrigated temperature pastures)
- Provide high-quality forage for carry-over into the winter in the form of forage, hay or silage
- Increase the level of animal production per unit area of land
In sweet veld, on the other hand, the major role of cultivated pastures is likely to be one of the following:
- To provide forage for summer use when rangeland needs to be rested
- To provide hay for drought periods
- To increase the total amount of forage available for animal feeding
- To increase the level of livestock production per unit area of land
In mixed veld, the major role of cultivated pasture is likely to be as follows:
- To provide forage in early summer, when it is often in short supply
- To provide fodder during the summer in order to rest the rangeland
- To provide high-quality forage during the winter months
- To increase the level of livestock production per unit area of land
FORAGE PRODUCTION PLANNING AND LIVESTOCK PRODUCTION SYSTEMS
The efficiency of any pastoral system primarily depends on the following factors:
- The amount, quality and seasonal distribution of forage production, which is a function of soil type, the amount and seasonal distribution of rainfall and the availability of irrigation
- The proportion of the feed consumed by the animal
- The efficiency with which the animal uses the food consumed
The objective should be to match feed demand with forage supply. Whereas the general principle of forage production planning applies to all pastoral livestock enterprises, each has distinctive characteristics that merit special attention. These specific requirements are a function of the system being adopted within each enterprise, and for the system to operate effectively, a particular set of conditions needs to prevail irrespective of where in the country that system is used.
ALTERNATIVE FEED CROPS
Given the current state and limited potential of some vegetation resources over much of South Africa, and the low productivity of the national livestock herd, alternative feed crops should be established as a priority. It is important to realise that rangeland and cultivated pastures can play complementary roles in providing quality feed to livestock and markedly increase forage production. There is undoubtedly considerable untapped potential for cultivated pastures in many parts of the country. A strategy to develop this potential would make it possible to increase forage production and improve productivity and efficiency of livestock to such levels, that South Africa can become self-sufficient in livestock products and also compete in the international arena.
South Africa is impacted by the following global factors, which inform and justify an initiative to promote the utilisation of alternative feed crops, namely:
- The growing negative effects of global warming are a reality.
- The growing demand for water is exceeding the scarce and limited water resources.
- The competition for limited water resources is favouring human consumption (total use).
- The effects of recurring and increasingly persistent droughts or feed shortages for animals.
- The dense and often impenetrable, infestations of alien invader plant species on several hundred thousand ha of natural pasture (veld).
- High levels of unemployment and the lack of viable opportunities to support livelihoods.
Cactus pears is one such an alternative fodder crop. it ideally adapted to drier conditions in large parts of South Africa, yielding large volumes of cladodes and fruit. They are efficient users of water and versatile multi-use crops with a range of proven applications for humans and animals.