Ranchers almost always welcome a good rain and optimistically hope timely precipitation continues through the growing season. But as realists, they know that today’s rain just might be the last of the summer.
Land that looks, in June, like it could provide almost unlimited forage might become brown and sparse by August, leaving it susceptible to overgrazing.
Vigilance, coupled with flexibility in a grazing plan, is critical for making the most of available forage while preventing long-term damage to the resource.
“The key word is ‘watch’,” says University of Nebraska agronomist Bruce Anderson, PhD. Producers need to closely observe their forage and how it responds to the weather and grazing, and base decisions on those observations. Recognize how rapidly or slowly forage plants are accumulating and make decisions early enough in advance to make a difference.
A common mistake, Anderson says, is that managers do not recognize a trend, such as declining forage growth, in time.
He recommends that producers sit down on a regular basis — about once every week during the growing season — to estimate how much total grazing is available in terms of cow days, pounds of animal per acre or whatever measuring units they prefer. Estimate forage production, based on current soil moisture and plant growth, if no more rain falls during the growing season. Also estimate production for other scenarios such as “normal” or higher-than-average rainfall.
Texas Agrilife Extension range specialist Charles Hart reminds ranchers that a good assessment of native range conditions does not begin during the growing season. Conditions going into the previous fall, and winter moisture, play key roles in forage growth.
Following a dry fall and winter, spring rains will green things up, but forage productivity could be significantly limited, he says. Cool-season grasses and some broadleaf forage plants begin growing and storing carbohydrates in their roots in the fall and into winter. Given good conditions, they’re just waiting for warmer spring temperatures to grow vigorously. But if moisture is limited during fall and winter, good conditions in the spring might not be enough.
Hart says he and his Extension team encourage producers to go out and look at grazed pastures and take stock of how much forage is grazed and how much is left. Sometimes during the growing season it can be difficult to assess the positive or negative impacts of grazing. A simple 6-by-6-foot enclosure using fence posts and wire panels in a pasture can provide an excellent visual reference for assessing how much forage is taken off during grazing and how well plants recover during rest periods.
A variation of this idea is to look at protected areas where cattle don’t graze — brushy patches or places infested with thorny plants such as prickly pear. If forage plants look significantly stronger in the protected areas than on grazed land, it could suggest declining range conditions.
Hart says he also trains ranchers to pay attention to the makeup of their forage base, which species are there and how cattle use them. If the makeup of desirable and undesirable species is changing, it could be a sign of overgrazing or, in some cases, under-grazing.
Longer-term changes such as significant erosion or increasing bare ground might be relatively easy to see. But spotting changes during the growing season that might suggest immediate changes in grazing plans takes careful vigilance.
Photographic reference points can be useful for season-to-season comparisons, but Hart advises caution, saying you need to account for differences in weather conditions. Forage in the photo point might look sparse in a dry year and green the next, but the true indication of the pasture’s health is the types of plants that emerge when moisture returns — diverse, desirable forages or weeds. Just because a pasture is greener doesn’t mean it’s headed in the right direction.
Most producers are well familiar with the environmental conditions on their ranches, Anderson says. They can use that experience and knowledge to periodically estimate forage conditions and production, and project the effects of drought or other changes.
The key is in knowing how to adjust management to use available forage efficiently while protecting the resource from long-term damage.
Anderson says a common mistake he sees in rotational-grazing systems is that producers leave cattle in paddocks too long. They graze the grass too short, causing a reduction in photosynthesis, depletion of root reserves and slower re-growth. “If you leave some forage behind,” he says, “you don’t really leave it behind. It helps make more forage available later.”
Anderson also stresses the importance of adjusting grazing practices depending on the season and growth patterns of forage plants. At this time of year, he says, cool-season grasses in many areas will start producing seed heads, which reduces forage production. He recommends speeding up rotations, moving cattle through as many paddocks or pasture areas as possible so grazing activity can prevent heading.
If you can’t keep up with grazing, cutting some pastures for hay prior to heading can be a good option. You’ll have hay available for feeding as needed and can return cattle to those pastures for grazing later in the summer. As grasses start to elongate, Anderson says, begin slowing the rotation to ration remaining grass and to guarantee that paddocks get enough rest for re-growth.
Keep stocking rates flexible
Hart encourages ranchers to stay as flexible as possible in their stocking and grazing decisions, especially in areas most susceptible to drought. He recommends keeping breeding herds at 50 to 70 percent of the land’s carrying capacity in normal years. Having the ability to reduce cow numbers during drought years or expand numbers with stocker cattle in years of excess forage can be a great benefit.
Charlie Christensen, who raises cattle in several counties west of San Angelo, Texas, uses that approach. “We stay adequately stocked — or I should say adequately under-stocked — and rotate our cattle to different pastures all the time, depending on conditions,” he says.
“In this region it’s not economical to feed hay to cattle so we only provide protein cubes to supplement,” he says. “But we stay as lightly stocked as possible and spread as many cattle as possible over as much land as possible. That way, if it doesn’t rain for three months or so, we don’t have to go into panic mode. We can wait and sell our cattle at the right time.”
Earlier this spring, Christensen said his pastures were providing more than adequate forage material for the numbers of cattle on them, but added that if dry conditions continue, he’ll plan to feed supplements and possibly reduce numbers.
Some, such as purebred producers, Hart notes, have less flexibility in cattle numbers. Ideally they can compensate with their land base. By stocking at well below carrying capacity for normal years, they probably can maintain numbers through a drought and could bring in stocker cattle during high-production years.
Anderson and Hart both advise looking for the uniformity of grazing to optimize forage use. If cattle are over-using some areas and under-using others, adjust accordingly.
Herding cattle to new grazing areas can be a good option, provided a water source is available. Water often is the limiting factor in rotational-grazing systems, along with the logistics of fencing off multiple paddocks. If cattle are overgrazing an area around a favorite water source, Anderson says, you might need to use temporary fencing to restrict access or turn off the water pump to encourage them to graze elsewhere.
Getting cattle to graze under-used areas might mean setting up a temporary water source and hauling water for a short time. An above-ground pipeline also could serve as an option for delivering water to temporary grazing areas, he says. If cattle use the area only during the grazing season, you might not need to bury the line.
Supplements such as mineral tubs or blocks also can help attract cattle to under-used grazing areas. Once cattle know where they are, the supplement can draw them some distance from water, but if the distance is too great, you need to provide a water source along with the supplement.
Forcing cattle to graze in under-utilized areas provides double benefits, Anderson says. First, you use that additional forage, and grazing probably improves the health of the ecosystem in these areas. Secondly, you provide a longer rest period for other grazing areas, making them more productive.
Hart adds that for ranchers who have them, these under-used areas can serve as an insurance policy for drought years. They offer emergency forage when it’s needed, although with some extra labor for herding cattle, providing a temporary water source and hauling supplements.
High feed prices and tight margins make it more important than ever that ranchers refine their grazing strategies for efficient and sustainable use of their forage resources.
Impact of overgrazing
Texas Agrilife Extension range specialist Charles Hart reminds producers that leaving cattle in a pasture too long without adequate forage can severely reduce long-term carrying capacity. Ecological damage could include:
Reduction of plant and litter cover, allowing more runoff and less moisture reaching the root zone.
Increased erosion, removing topsoil needed for plant production.
Decrease in organic matter in the soil.
Depletion of plant roots, reducing the plant’s ability to recover after grazing or extreme environmental conditions.
Invasion of undesirable plant species.