|Jackson, Randall -|
Submitted to: Forage Focus
Publication Type: Popular Publication
Publication Acceptance Date: April 29, 2013
Publication Date: May 8, 2013
Citation: Brink, G.E., Jackson, R.D. 2013. Grazing management effects on pasture productivity – extent of grazing. Forage Focus. 8:15-16. Technical Abstract: How does grazing using the “take half – leave half” rule actually affect annual pasture productivity? Is residue height a concern when mature grasses are mob grazed, a management alternative to grazing at a vegetative stage? A range of grazing management systems was implemented at the U.S. Dairy Forage Research Center at Prairie du Sac, Wisconsin, on 1.0 acre paddocks of meadow fescue, orchardgrass, quackgrass, and reed canarygrass. Within each paddock, we determined how the extent of grazing (grazing 50, 75, or 100% of forage) affected growth of cool-season grasses grazed at either the vegetative or mature stage. In years with either below- or above-normal rainfall, orchardgrass and reed canarygrass had greater annual yield than meadow fescue or quackgrass. Grazing vegetative grasses to remove 100% of forage provided no more annual yield than grazing to remove 75%, but significantly increased the risk of reducing grass persistence and delayed growth the following spring, up to one week. Take half – leave half grazing management (50% removal) always reduced annual yield, but did shorten the rotation interval and resulted in earlier grazing the following spring. Forage quality was not affected by residue height. For grasses grazed at mature stage, there was no yield advantage in intentionally leaving any residue above that which is normally trampled by livestock, and no apparent effects of extent of grazing on persistence. Grasses grazed at mature stage only had about 10% more litter residue on the ground at the end of the season than those grazed at vegetative stage. Maintaining adequate residual sward height throughout the grazing season is important for sustained pasture productivity and persistence, and greater uniformity of yield distribution.