Article: Southern Africa’s Experience with Intensive Short Duration Grazing
Authors: Skovlin, J.
Published: Rangelands 9(4), August 1987
This paper points to previous research by Tainton that highlights the tension between utilization and animal performance. In some cases where stocking rates are managed at very high levels for high utilization, animal performance is likely to suffer:
“On the animal side, one must compromise between high performance grazing (HPG – also called controlled selective grazing) to optimize livestock daily weight gain and high utilization grazing (HUG – also called nonselective grazing) to force use of less palatable plants.”
HUG can be a useful strategy when a manager is attempting to affect the trajectory of species succession. Less palatable and less nutritious plants are often consumed by cattle once the most palatable forage is gone. The removal of weedy and/or shrubby species through high utilization can change species composition and succession in ways that both managers and scientists cannot always predict. However, high utilization can also expose soil and deteriorate range quality, and should be approached with caution and careful consideration of the ecosystem in which it is being applied.
While cattle and other livestock can be used to control weeds in some situations, this approach requires careful attention to animal behavior and performance. Research by Dr. Fred Provenza has shown that animals with better nutritional status can better handle the toxicosis often associated with consuming unpalatable weed species. The provision of nutritional supplements can be a management intervention used to facilitate this process.
Another interesting aspect of this paper is research on the effect between grazing days and recovery periods. Intensive short duration grazing implies brief periods of grazing per paddock at high animal densities. A practical consequence of this requires greater investment in fencing and water points to sub-divide paddocks into ever smaller units, or greater investment in field labor to herd cattle and control their movement across the landscape.
Research conducted in southern Africa shows that a middle of the road approach might be more economically sound:
“Studies by Tainton et. al. (1977) compared variable days of grazing and rest (9 combinations) on grass yield for 6 years. In general, highest yields came from the lowest days of grazing and highest days rest. However, the 7 paddock rotation (10 days graze and 60 days rest) yields as well as the 21 (2 days graze and 40 days rest) and 31 (2 days graze and 60 days rest) paddock system. From results of this study more than 7 paddocks would be unjustified”.
When applying these research lessons to actual management scenarios, the manager should proceed with the holisticgoal as a key frame of reference. How many paddocks are installed on the landscape will a function of numerous factors, including availability of labor and capital, the description of the future resource base, market considerations, and the anticipated effect of animal impact and grazing on animal performance and range quality. Generally, the best approach is to make decisions in accord with these factors, and to proactively monitor one’s progress.