by: Kim Mullenix, PhD
Extension Beef Cattle Specialist
The winter is typically a time that we count on for rainfall and cooler temperatures in the Southeast. By the time you read this article, significant rainfall may have fallen around the state already. However, this does not mean we are "out of the woods" on drought conditions. Many parts of the state are still well below the average annual rainfall for that area. Most of our perennial grass pasture systems were overgrazed last summer simply because we were trying to get as much forage into our cattle as possible during a time of low productivity. While the intentions of this approach were good from the standpoint of the animal, we may be facing a significant tradeoff and downfall for the plant side of the equation. As we move into the winter and spring, it is likely that our perennial grass pastures will start to show signs from continuous grazing pressure during periods of drought. In order to address the problem, we must first understand the mechanism for how plants respond under stressful conditions. So what happened to our perennial grass pastures this past year?
Forage Management is A Supply and Demand Process
Under drought conditions, animal demand continues while forage supplies may be slim to none!
• Limited due to dry conditions.
• Plant growth slows or stops due to lack of moisture.
• Root growth basically stops
•Forage dry matter intake continues regardless of if plants continue to grow.
• Animals will try to take more bites to compensate for lack of forage growth ... this means more walking around and grazing forage closely to the ground.
What You Can Do Right Now to Help Your Pastures Recover
*These recommendations are particularly timely for those with tall-fescue based pasture systems.
Rest - Green does not always mean go!
• While it may be tempting to turn cattle out into a pasture as the first break of green begins to pop through, this is an extremely critical time for the plant. Our first reaction in this case is often to "open the gates" or let cattle have access to multiple pastures. We are asking our forage crops to do a lot of things at this point in time. As tall fescue begins to recover, it will rely on root reserves to generate aboveground leaf area. This leaf area acts as the "solar panel" for the plant, and must be well-established to capture light, which promotes further growth and production. Plants recovering from periods of long-term stress, such as drought conditions, will likely have a slower recovery time. Grazing forage when it is short and barely emerging 1) reduces leaf area needed for regrowth and 2) causes the plant to rely on potentially depleted root reserves to generate regrowth. Basically the plant needs to work from the bottom up to start growing again. As the roots deplete their pantry of resources, there is nothing left for the plant to come back from. Ultimately, this may cause a further decrease in pasture persistence. Early winter green-up is simply a time when tall fescue is preparing for temperatures to moderate some in the spring and the plant is in more of a holding pattern. Significant dry matter accumulation will likely not occur until more mild temperatures begin to occur in the early spring. If we continually clip it back during this tender stage in early winter, this equals a limited root system = little regrowth = little forage for later!
Designate a sacrifice paddock and feed cattle only in that area.
• A sacrifice paddock is a designated area on the farm where cattle can be held and fed for a given period of time. This may consist of several paddocks in larger operations.
• The recommended minimum amount of space needed in a drylot situation is 500 to 800 square feet per cow-calf pair.
• Considerations - Level, well-drained area. This way when rains do come, you aren't completely mucked and mired in.
• Be sure cattle have adequate access to water and light.
Residual - Leave some for later.
• If and only if pastures have adequate, productive regrowth should grazing be considered. The target height range for the initiation of grazing is 4 to 8 inches for tall fescue. However, allowing forage to reach the taller end of this range will allow more time for rest and recovery before grazing. A good rule of thumb is to “taken half, leave half” once grazing begins. This recommendation is based on the need for a healthy root system and plenty of leaf area to capture light.
Not sure that your perennial grass pasture will recover from the drought?
The next article will focus on how to conduct a pasture assessment to determine the potential for pasture recovery following drought conditions.
Where can I find more information on drought management and other topics?
The Alabama Cooperative Extension System has created a Drought Response Taskforce that has compiled a central resource for drought management information for crops and livestock. The website is: www.alabamadrought.com
For livestock, this site contains:
• Alabama Commodity Feed List• Timely Information Sheets on - nitrate toxicity, forage testing, supplementation strategies, and grazing management during drought.
A list of available programs from the USDA Natural Resources Conservation Service Alabama can be found at: https://www.nrcs.usda.gov/wps/portal/nrcs/mainJal/ programs/
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