Posted 16 July 2007. Forage and Grazinglands.
Windrow Grazing Shows Promise in Northern Minnesota
University of Minnesota. www.cfans.umn.edu
St. Paul, Minnesota July 2, 2007--In the Northern Great Lakes Region, the forage growing season is short, lasting about 120 days. This means that beef producers are constantly looking for ways to reduce their winter feeding costs.
Windrow grazing, an alternative method for reducing winter feeding costs by extending the grazing season, is used extensively in the northwestern United States and Canada. This grazing system allows cattle to graze later into fall and early winter and reduces the cost of processing, hauling, and feeding hay. However, moisture concentrations in the northern United States and Canada are considerably lower than in the Upper Great Lakes Region.
Increases in moisture may have a negative effect on nutrient concentrations in windrows, particularly energy, over a period of time. However, preliminary University of Minnesota research data indicated that the concentration of nutrients (crude protein and total digestible nutrients) in forages left in windrows over time do not significantly decrease.
U of M research was conducted in 2006 at the North Central Research and Outreach Center in Grand Rapids, Minn., to determine if pregnant dry cow performance is affected by grazing windrows versus stored forage. Costs associated with both feeding systems were also compared. The study found that late fall grazing of windrows of both ryegrass and mixed grass pasture systems effectively reduced feed cost by extending the grazing season -- without negatively impacting cow performance.
In the 2006 study, pregnant dry beef cows were assigned to one of two treatment groups within two pasture types: cows fed baleage harvested from one-half of each pasture type, and cows grazing windrows on one-half of each pasture type. The two pasture types were annual ryegrass and a mixture of alfalfa, tall fescue and annual ryegrass. The pastures were seeded in early June, grazed or clipped in late July, and then cut or windrowed in early October. Cows were on treatments for approximately 30 days beginning in early November.
In the mixed grass pasture, the average daily gain was greater for the baleage-fed cows (3.7 pounds) than for cows grazing windrows (2.1 pounds). In the ryegrass pasture, average daily gains were similar (1.9 pounds) for both the baleage and windrow groups.
In the ryegrass pasture, forage loss was found to be greater with windrow grazing (14 percent loss) than with the baleage-fed group (4 percent loss). However, forage loss was similar for both windrow grazing and baleage-fed groups in the mixed grass pasture, at 7 and 5 percent, respectively. Over time, forage crude protein levels remained similar for both treatment groups; however, total digestible nutrients (TDN) declined slightly for the windrow versus baleage-fed group in both pasture types.
Feeding cost per head per day was greater for the baleage group for both the ryegrass ($1.26) and mixed grass ($0.99) pasture types, as compared to the windrow grazing group for both ryegrass ($0.35) and mixed grass ($0.54) pasture types.
Ryon Walker is an educator and beef cattle specialist with University of Minnesota Extension.