Summary
Climatic variability is the single largest cause of poverty in pastoral societies, resulting in increased livestock mortality and low productivity. Browse can be a major constituent of livestock diets throughout the year, but is especially important during the dry season, during droughts, and under most communal grazing conditions. However, little was known about what constrains its productive potential. The project sought to develop techniques for assessing the productive capacity of rangeland in relation to climatic and other environmental variability; to identify production constraints and analyse management strategies which address the temporal and spatial variation in the productivity of rangeland systems; to develop a decision-support system to assist policy scenario analysis.
|
|
| Primary Relevance |
Low - High |
| Feeding and Nutrition |
 |
| Animal Health |
|
| Commodities and Markets |
|
| Other Husbandry |
|
| Policy Relevance |
 |
|
Flexible stocking strategies alone are not likely to be successful in coping with droughts. For subsistence pastoralists, the traditional policies of maintaining the maximum number of breeding stock, and of hoping that most of them will survive drought, may be as close as 'opportunistic' management can get to dealing with climatic variability. We also showed that, in seasonally variable environments, the supply of dry-season forage determines the numbers of livestock that can be carried. Wet season resources may be important for production, but maintaining livestock numbers depends on dry-season nutrition. Browse could make a significant contribution here.
Browse is a dependable forage that is available over a longer growing season than grass. Its production may equal or exceed that of grass, and it may be the only forage available in heavily-utilised areas. Assessment of browse biomass is quite easy and methods of estimation we developed could be used as a rapid means of field assessment of range capacity. In an investigation into ways to manage browse resources, we showed that lopping branches in the late dry season can provide valuable forage, particularly as a source of N, at a critical time of year. Lopping stimulates re-growth and appears not to affect the survival of tree.
Cattle and goats use different forms of browse, with cattle selecting predominately the large-leaved species, while goats can make efficient use of the small leaved species as well. There is little competition between the two livestock species. Mixed grazing and matching the ratio of animal species with forage resources would, therefore, be advantageous for livestock keepers in semi-arid regions where grass biomass has been depleted by high stocking rates.
The objectives were to:
- develop techniques for assessing the productive capacity of rangeland in relation to climatic and other environmental variability;
- to identify production constraints and analyse management strategies which address the temporal and spatial variation in the productivity of rangeland systems;
- to develop a decision-support system.
|
