By Jessica A. Williamson
Although it is tempting to open the paddock gates and let livestock graze where and what they can find, maintaining a managed grazing system and keeping animals off scorched forages can be the key to healthy pastures in the fall and next spring.
Amidst one of the worst droughts parts of the northeast has seen in quite a while, it is tempting to throw managed grazing systems out the window, open the gates, and let animals pick and choose what and where they can forage within the paddocks on the farm. But it is especially important during drought that pasture rotations are maintained and animals are kept off pastures that do not have adequate regrowth.
In many cases in Pennsylvania, a grazing livestock farm's sole source of feed during the months of May through November is cool season perennial pastures. There are no warm season annual or perennial forages as a feed source, resulting in a shortage of feed during the summer months and especially this year, with the hot temperatures and dry conditions. Rotational grazing is always a good way to help stretch your forage availability, as rotational pastures have been shown to have greater carrying capacities and stocking rates, as well as reducing selective grazing resulting in more uniform and complete utilization of available forages compared to continuous pastures. However, when a drought like this comes around, even the best rotational systems are struggling with a forage shortage.
When pasture biomass is long gone and you are tempted to open the gates and let livestock graze freely around various paddocks, similar to a continuous system, you are causing more harm than good. Selective grazing ensues, and animals will graze portions of the pasture over and over again, depleting the nutrient stores and root system in the plant, causing an even greater stress on the forages during the drought. This depletion of nutrients will cause the plant to struggle to regrow when rain does come, and could cause the pasture to struggle over-wintering.
It is important to never graze cool season perennial pastures under a 3" residual height, and this especially rings true in a drought. When the rain begins again, and rest assured, it eventually will, a 3-4" stubble height in pastures will give the forages an opportunity to take off and grow again, causing a boost in productivity for fall grazing. Animals should not be turned into a cool season perennial pasture until forages reach heights between 6-8”.
When in a drought situation where forages in the pasture are very minimal, it is recommended to feed hay or supplementation in a sacrifice area, just like a winter feeding scenario, to keep the pasture damage confined to one small area where there is heavy hoof traffic, rather than spreading the damage across the whole farm from over-grazing. A sacrifice area allows animals to stay off scorched pastures until rainfall ensues, temperatures cool, and pastures begin to regrow. A cool, shady area with fresh water is best to feed livestock during this time of year.
Source:psu.edu