Reducing grazing pressure on native rangelands and keeping herds of cattle adequately nourished can be compatible goals, according to Agricultural Research Service scientists. It just takes the right grazing strategy.
Marshall Haferkamp, a rangeland scientist at the agency's Fort Keogh Livestock and Range Research Laboratory in Miles City, Mont., has found that using pastures seeded to certain cool-season perennial grasses can provide animals with ample nutrition, especially during the months when lush, green forage is hard to come by.
In addition, ranchers can use these seeded pastures to shift grazing pressure away from native rangelands in the spring and autumn, allowing possibly fragile or recuperating sites to recover.
In the semiarid regions of eastern Montana - where the Miles City laboratory is located - ranching on native rangelands means relying to a large degree on Mother Nature. According to Haferkamp, the rains that come in April, May and June usually determine how much forage is available in a given year for grazing cattle.
This unpredictability is one of the reasons Haferkamp wanted to explore selected cool-season grasses - for grazing in the spring and autumn - as potential forages for rounding out a herd's yearly nutritional needs.
Not only would the grasses need to take well to the Northern Great Plains environment, they would also need to be digestible and nutritious for cattle.
Working in collaboration with ARS animal nutritionist Elaine Grings and ARS geneticist Michael MacNeil, Haferkamp found that cattle gained more weight in the spring and autumn while grazing on seeded pastures than on native rangelands.
The most promising cultivars included spring cultivar "Hycrest" crested wheatgrass and autumn cultivar "Prairieland" Altai wildrye. "Hycrest" was developed by plant breeders at ARS' Forage and Range Research Laboratory in Logan, Utah.