Wet conditions call for careful hay management
Wet conditions call for careful management to preserve hay quality, a South Dakota State University dairy specialist said.
SDSU Extension Dairy Specialist Alvaro Garcia said current high moisture conditions due to rain in parts of South Dakota can hamper forage harvest and storage and result in losses through heating and/or mold growth.
Baling hay into large round bales is a common harvesting method in South Dakota, both for labor efficiency and ease of handling. Quality hay is one of the key components of a highly palatable and digestible diet for ruminants. But improper handling can result in storage and feeding losses that reduce quality and result in costly waste.
Garcia said the “right time” for cutting hay is determined not only by the maturity of the forage, but most importantly by a reasonable prediction of weather conditions in the next few days.
Rain that penetrates uncovered bales left in the field leads to substantial deterioration and loss of feed value. Storage losses can represent easily 15 percent or more of the dry matter when bales are left uncovered and exposed to rain, Garcia said.
Added feeding losses can compound the problem and result in an additional 25 percent of the feed being wasted. Research has shown that differences between covered and uncovered large round bales can be almost 30 percentage points with total losses (storage plus feeding) of uncovered bales being close to 45 percent of the dry matter.
“The monetary value of these losses can be sizeable for average dairy producers, who may harvest enough hay to feed 1,500 pounds daily for every 100 cows,” Garcia said.
Garcia noted that in these calculations, only hay dry matter losses are factored in and not losses in milk production. Dry matter losses are usually those of the most digestible nutrients in the forage, for example, easily digestible carbohydrates and bound proteins.
“For hay worth $100 per ton, if producers are able to reduce storage losses by 10 percent by covering round bales stored outside, this represents $7.50 of savings per day for every 100 cows fed or roughly $2,700 per year,” Garcia said.
If covering hay with tarps pencils out as costly, Garcia suggests producers think about options such as building a gravel-floored storage shed.
“An 18-feet high pole construction shed measuring roughly 20 by 60 feet can accommodate 100 large round bales and can reduce losses by a total of roughly 10 tons of hay annually, or $1,000,” he said. “These savings would have to be compared with the cost of building the shed and the years it will take for it to be paid for with these kind of savings.”