Putting a roof over your hay can significantly increase its quality, according to new research from Louisiana State University.

But if you can't afford a shed, tarping is the next best thing to increase both quality and intake, says David Sanson, cattle nutritionist at the university's Rosepine research station.

Hay stored in a barn retained 25% more TDN and crude protein compared to hay stored outside. Hay stored under tarps retained 10% more nutrients.

The losses will mount when the hay is fed, says Sanson. An earlier Louisiana study revealed that as much as 50% of hay is wasted when outside storage losses are combined with increased wastage by livestock.

“As forage quality increases, the amount of forage an animal will consume increases,” Sanson points out.

His studies involved round bales of ryegrass hay grown for cow-calf and stocker cattle programs. Even though its overall quality was lower than that of high-quality alfalfa, he feels the quality-loss comparisons would be comparable for all types of hay.

The study gauged the amount of TDN, crude protein and dry matter lost from hay stored for six months. Hay stored in a barn lost only 1.9% of its harvested TDN, compared to 10.5% lost from the tarp-covered hay stacked outdoors in a pyramid manner. Uncovered hay had a 26.7% loss in TDN.

Crude protein losses were 25.6% for uncovered hay, 10.8% for tarped hay and only 3.1% for barn-stored forage.

The amount of harvested forage weight lost for the tarped hay was nearly 14%. That compared to just over 4% weight lost for barn-stored hay.

At the start of the study, Sanson determined that each bale contained enough TDN to meet the energy requirement of a 1,000-lb gestating cow for 58 days and enough crude protein to meet a cow's requirement for 98 days.

“Loss of TDN from hay stored in the barn equaled this cow's requirement for one day,” he reports. “But for hay stored beneath tarps, the amount of TDN lost equaled the cow's energy requirement for six days. It equaled 16 days for uncovered hay.”

“Depending on the price of hay, the difference in losses will exceed nearly $2/bale on hay costing $20/bale to much more than that on high-quality hay,” says Sanson.

“Within five or 10 years, savings should easily pay for a 40 × 112' barn needed to store about 300 round bales.

“I would recommend a barn if that is financially possible, but a tarp is a cheap alternative and much better than storing the hay outside. The cost of the tarp could be recovered in less than two years.”