March 4, 2010 - While there are a number of grazing systems for livestock producers to choose from, a range specialist with Texas AgriLife Extension believes that the stocking rate is the most important decision a rancher can make related to the health of livestock and land.
"Your grazing system is not a magic bullet," noted Dr. Robert Lyons. "If the stock rate isn't right, the grazing system won't work."
Stocking rate, as defined by Lyons, is the amount of land allotted to each animal for the grazeable potion of the year. The size of the animal, stage of growth, the size of the pasture or ranch and the number of grazeable acres all should be taken into account when choosing a stocking rate. Once the rate has been selected, Lyons recommends being flexible as a way of reacting to changes in the weather and other factors.
Lyons recommends establishing a carrying capacity -- the maximum long-term stocking rate that can be sustained without harming the land -- but cautioned that the carrying capacity for any given pasture is not set in stone.
"In Lampasas County, where I was for a while, the average yearly rainfall was 28 inches," he said. "Now I'm in Uvalde, where the average rainfall is 22 inches. There is no way you can have the same stocking rate for the two areas. If the stocking rate is too high, the land resource and the animal will suffer. Having more animals than the land can support won't make you more money -- it will end up costing you money."
Lyons also remindeds tproducers that Texas has very few "average" years related to rainfall and the best strategy is to stock in preparation for one of those "extended dry spells" that the state suffers regularly. Otherwise, he said producers will find their pastures are overstocked at least half the time.
"If by the end of June, you haven't had your county's average rainfall for the year, it's time to do something if you're stocked on the basis of an 'average' year," he said. "We've had good rains this winter because of the El Nino effect, and the climatologists are telling us we should be able to expect that trend to continue until the early part of the summer. But. we will have another drought. You can be sure of that."
By stocking for the land's carrying capacity, producers are able to leave some grass in the pastures where it helps protect the pasture grass from freezing temperatures and erosion.
"Always leave something out there," he said. "You don't want your pasture grazed to the ground -- ever. Leaving some residue helps you keep what you have by not allowing it to run into a stream or gutter or into the Gulf of Mexico. If you leave some stubble, that protects the plant and keeps the root system strong."
Lyons pointed out that all ranges are not ecologically equal, either. In areas of West Texas and the Hill Country, a range might be large but that won't mean anything to the cows if they have a hard time accessing the land because of rocks and brush.
In a study that Lyons conducted in the Hill Country, cattle were equipped with a Global Positioning System (GPS) collar and their movements over a particular ranch were tracked. He noticed one area where the cattle never went and he wondered why. When Lyons checked out the site he found a trail leading into the section but also a lot of rocks and a wall of brush that discouraged the cattle from entering.
"Look at it like this," Lyons said. "If it's hard for you to walk over a piece of land, it's probably hard for the cattle to walk on it too, so they won't."
While the timing, intensity and frequency of grazing are important decisions, Lyons emphasized that choosing a sustainable stocking rate will always be the most important decision a rancher will make.
"Your stocking rate will go a long way toward determining how productive the animal will be and how much money you make," he said. "It's also a critical element in maintaining you range as a resource. In the end, it's going to affect just about every aspect of your operation, so make sure you get it right."
