April 5, 2005
At Iowa State University, a long-term project designed to improve the meat quality of beef cattle continues to produce results. At the same time, a new project studies ways to protect water quality in pastures where beef cattle graze.
The water-quality project is led by James Russell, animal science professor. "Some studies have shown that poorly managed grazing increases sediment and phosphorus loading in pasture streams," Russell said. "But no one has looked at the effect of well-managed grazing on streams."
The beef-breeding project began in 1997. Doyle Wilson and Gene Rouse, now emeritus professors in the ISU animal science department, initiated the selection project to investigate the genetic relationships between carcass traits such as marbling and yield. James Reecy, assistant professor in animal science, now supervises this project. Wilson continues to be involved.
The 2003 closing of ISU's Rhodes Research and Demonstration Farm required researchers in these and other beef projects to make adjustments. But the dust has settled, and work is moving forward with an emphasis on finding answers to the questions Iowa cattle producers face.
Maynard Hogberg, chair of the animal science department, said there are no plans to sell the Rhodes farm. "Two-thirds of the farm has been rented to a young, local farmer with cattle, with a bid process used to arrange the rental agreement," Hogberg said. "The remaining portion of the land will be used for the managed-grazing project. This arrangement allows the important research on how to minimize runoff from grazing lands to continue. There still is a real need to find solutions on how to manage grazing programs to reduce nutrient runoff into streams."
The purebred Angus cattle that had been housed at the Rhodes farm were moved to the McNay Research and Demonstration Farm near Chariton. Cattle previously used for research at McNay were sold to make room for the Rhodes herd.
"Most of those were crossbred cows, bred for spring calving," said Mark Honeyman, coordinator of ISU's research and demonstration farms. "We've replaced those with the purebred Angus cows from Rhodes. A number of research projects that had been conducted at Rhodes have moved to McNay."
Honeyman said money from the sale of cattle, plus rent from the Rhodes farm, is being used to pay employees on other research farms, pay off a deficit from the Rhodes farm and improve facilities at McNay.
The selective breeding project has yielded important information on genetic traits that lead to higher meat quality, especially more marbling. Some top cows from the project have been sold, and one outstanding bull has been sold to an international bovine genetics company.
"We said we wouldn't sell any of the breeding stock, unless we developed some elite animals from which the industry would benefit," Reecy said. "That has been the case."
Reecy also uses the Angus herd for research on the growth and development of skeletal muscles. "To improve livestock production in the future, we're working to identify DNA markers that are associated with traits of interest, such as marbling and meat tenderness," Reecy said.
The Angus herd at McNay includes about 400 purebred cows. While at Rhodes, all the cows calved in the spring. Now the herd is split, with two-thirds calving in the spring and one-third in the fall. The original McNay herd had been split the same way, spreading the workload and helping faculty and staff provide practical advice to producers on fall calving.
Some of the Angus cows will be moved back to the Rhodes farm for Russell's managed-grazing project. The project will use 180 acres divided into six, 30-acre pastures. Fifteen fall-calving cows will be placed in each pasture.
Willow Creek runs through the pastures. "We're going to evaluate three treatments, each replicated twice," Russell said. "The first treatment will involve continuous grazing, where the cows have full access to the stream. The second also will be continuous grazing, but access to the stream will be limited."
For this second treatment, the cows will be able to reach the stream only at locations where the bank has been stabilized with fabric and rock. The remainder of the stream will be fenced off as riparian buffers.
The third treatment will involve intensively managed, rotational grazing. "The cows will be fenced into smaller paddocks," Russell said. "They'll never graze in the riparian paddock longer than four days, and will be moved before they get the grass down to less than four inches." These cows won't be able to access the stream, unless they are grazing the riparian paddocks, so water will be piped into the other paddocks.
All the structural requirements for this project are in place, including fencing, alternative water sources, reinforced cattle crossings and riparian buffers. Cattle will be moved to the Rhodes farm about May 1 and graze there through mid-October.
The study will investigate ways to improve water quality by looking for solutions to stream bank erosion. Russell said global positioning system (GPS) equipment will be used to study cow behavior. "Where do they spend their time? We'll be considering whether we should provide mineral supplements or alternative water sources in areas away from the stream to reduce bank damage," he said.
Russell's project, which is scheduled to last three years, is funded by the Iowa Department of Natural Resources and the Leopold Center for Sustainable Agriculture.