If you control weeds in your pasture, the cows will thank you for it. Dr. Kevin Bradley, University of Missouri professor and researcher in the Department of Plant Science, told Ozarks Farm & Neighbor their studies have found if half a field is treated with herbicide, that’s where the cows will congregate. “The cows preferred to stay on a herbicide treated portion of a pasture anywhere from 1.5 to 5 times more than they stayed on the portion of the pasture that was not treated,” he said. The researchers ran their test at three Missouri sites, monitoring the animals with GPS tracking collars. “That’s a first step for us in being able to say you can show a lot of things on paper,” said Bradley.
Bradley said there isn’t objective data on when grassland is so weedy that it needs to be treated. “Everybody has their own trigger on what they think will justify weed removal,” he said. “There’s just not a whole lot of research data out there that say, ‘If there’s this many, then you should remove them.’ It’s something that’s desperately needed.” He’s also studied the nutritional value of weeds. “Common Ragweed, when it’s less than knee high and in that vegetative state of growth, has a protein content that would rival Alfalfa in a lot of years,” he said. The nutritive value becomes very poor when the plant matures, and in any event the plant is of no benefit if the animal refuses it. “Our next step in all of that research has been to try to show whether cattle will eat it or not,” Bradley said. “I’m not arguing the fact that there’s certainly situations where cattle will eat Common Ragweed, but… the cattle will prefer that weed-free grass, in my opinion, day in and day out.”
There are other weeds the cattle won’t take at all, noted Dr. John Jennings, University of Arkansas professor of animal science and Extension forage specialist. “Buttercup might be one; the cattle might eat those when they’re small, but when they get large and start to bloom cattle refuse them, and they produce a huge amount of shade that can reduce the growth of the pasture,” he told OFN. Woolly Croton causes similar problems; the weed appeared after some Arkansas fields got a flush of rain last August. “In a lot of areas the Bermudagrass was able to respond to the rain and grew well, but where the Woolly Croton came up it shaded the Bermuda and got virtually no growth underneath it,” Jennings said.
While the weeds are still small and relatively easy to control, Jennings said 2, 4-D (2, 4-Dichlorophenoxuacetic) will do a good and inexpensive job on common spring weeds like Buttercup and Chickweed. “In Bermudagrass pastures that are still dormant, a good application of glyphosate herbicide across those will clean up weedy grasses and broadleaves,” he said.
