Raising the cutterbar to increase alfalfa quality may not be a paying proposition for dairy farmers, according to early findings at the W.H. Miner Ag Research Institute, Chazy, NY.
The institute is evaluating the yield and quality of alfalfa and an alfalfa-grass mix cut at the currently recommended height of 2” vs. a 4” height common on many farms. The results from this year’s first cutting appear to support the shorter cutting height, says Everett Thomas, vice president of agricultural programs.
“Yields were significantly higher at 2 tons vs. 1.7 tons per acre of dry matter, with only a modest effect on predicted milk production per ton of alfalfa,” says Thomas. “Milk per ton was 3% higher for the 4” cutting height, but milk produced per acre of forages was 12% lower. While it’s too soon to make a conclusion, the small increase in quality from the 4” cutting height wouldn’t seem to be worth the much larger decrease in yield.”
An alfalfa-reed canarygrass mixture is being field- and hand-harvested at both cutting heights. The researchers analyzed the first-cut alfalfa and grass separately, and found very little difference in fiber digestibility.
“Based on the first harvest of this trial and a 2005 trial, I see no reason to mow higher than normal other than to avoid stones and field scalping,” says Thomas.