3.1 Grassland-based Systems (LG)
The importance of the grassland-based system in different world regions is shown in Figure 4. Central and South America and the developed countries dominant the picture in terms of meat production, together accounting for more than three-quarters of the world's production.
3.1.1 Temperate Zones and Tropical Highlands (LGT)
Definition and geographical distribution
The grassland based system in temperate and tropical highlands is a grazing system constrained by low temperatures. In the temperate zones, there are one or two months of mean temperatures (corrected to sea level) below 5°C, whereas in the tropical highlands daily mean temperatures during the growing period are in the range of 5 – 20°C.
The cases located in tropical highlands comprise parts of the highlands of South America and eastern Africa. The cases in temperate zones include southern Australia, New Zealand, and parts of the United States, China and Mongolia.
Fig. 4: Importance of grassland-based systems in different world regions
(Total meat production as percent and in thousand tons)
Fig. 4
Typical cases are Mongolia's steppe system, New Zealand's dairy and sheep enterprises, dairy systems close to Bogota, Colombia, South American camelid and sheep grazing systems in the Altiplano of Peru and Bolivia. Extensive grazing systems are also found in parts of northwest Pakistan involving sheep for mutton and wool (Nawaz et al, 1986) and transhumant sheep on degrading high altitude pasture in Nepal (Pradham, 1987). Further cases are reported for Chinese Merino wool sheep on communal grazing in Jilin Province and sheep ranching at high animal productivity in Oregon, United States on grass-clover pastures (Nawaz and Meyer, 1992).
Resources and production
Temperate breeds perform well in tropical highlands situations, except at very high altitudes, only encountered in the Andes of South America. Local breeds play an important role where subsistence objectives are still important, cash income is limited and few purchased inputs are used. At the other end of the intensity scale, New Zealand systems use highly selected animals, artificial insemination (AI) with fresh semen, and a range of advanced technologies to maximize animal output from the pasture produced.
By definition, range is the primary feed resource of this system. Quality varies widely. Oceania's systems involve top-dressing with fertilizers, introduction of legumes, appropriate fencing to achieve highly productive legume-grass pastures. Relatively even rainfall distribution and seasonal mating allow for comparatively high productivity levels using a minimum of hay or silage. In the less intensive grazing systems of Africa and Asia, seasonal fluctuations in feed supply are mainly buffered by the loss of weight of the animals. This, however, limits their productivity.
The developments in New Zealand document the potential of appropriate intensification, which allows for a highly competitive dairy and sheep sector, producing and exporting from a very remote part of the world in spite of heavy subsidies being applied by some competitors. The country has developed labour-extensive, not very capital-intensive technologies to enhance the productivity of the basic resource, a productive rangeland.
In the tropical highlands, the LGT system is affected by seasonality of fodder supply which, in turn, largely depends on rainfall patterns. Extensive systems adapt by accepting weight losses and reductions in milk output. Where milk markets generate the appropriate incentives, dairy cows are either fed cut-and-carry forages or, as is the case in the dairy system of the highlands of Bogota, Colombia, pastures are irrigated.
Product use varies widely, ranging from very commercially export-oriented New Zealand farmers, to South American farmers mainly producing for the domestic market, to Asian and African small-holders catering for local markets and their own subsistence.
Issues and perspectives
The regions in which the LGT system predominates have a combined human population of 190 million which represents only 3.5 percent of the world total, and almost half of this population lives in Asia. In OECD member countries far fewer people (14 million or 1.7 percent) use the LGT system, but they control more land and cattle per inhabitant than in the other regions (Table 1).
The major interaction is through the market, where the same animal products are supplied by mixed and landless systems. Market forces and environmental concerns are putting a ceiling on the potential for intensification of this system. Thus, globally, their market share is declining vis-à-vis other production systems.
The major environmental concern in the temperate and tropical highland grazing system is the degradation of rangelands through inappropriate range management practices. These rangelands are frequently part of watersheds, in which range degradation causes problems of flooding, siltation of rivers, etc. Nevertheless, these issues are normally less serious than in mixed farming systems where crop production is practised. Rangeland management frequently involves controlling wildlife, which either compete for forage, transmit diseases or, in the case of predators, cause mortality of animals.
Since the LGT system is found mostly in marginal locations, its production potential in global terms is relatively low. In developing countries it tends to form a subsistence basis for certain groups of the population. Here, its future role is seen more in providing employment for these groups than in making a major contribution to output and economic development. In developed countries, frequently with production surpluses, the production from these systems is declining in relation to other values and uses assigned to these land resources, such as the recreational value, value as a wildlife and biodiversity reserve, and the contribution to water conservation. Therefore, the extensification of production linked with increasing farm sizes may lead to production systems which are both economically viable and environmentally acceptable to societies at large.