This article was originally in the October issue of Drovers CattleNetwork.

The way you harvest and store hay actually determines wintering successes and costs for cattle.

Hay is often fed to fill a cow’s rumen without any concerns over the amount of nutrients contributed to her diet, but you can fill a cow’s rumen on low-quality hay without fulfilling her nutrient requirements.

If her nutrition is inadequate, performance such as weight gain, growth, lactation and calving will suffer. It is usually cheaper to preserve nutrient content of forages during harvest and storage than to purchase additional energy and protein.

Avoid harvest losses

“Stage of maturity at cutting and moisture content at baling are two of the most important factors affecting forage quality,” says Jimmy Henning, University of Kentucky. “Most forage will have a 20 percent loss in total digestible nutrients (TDN) and a 40 percent loss in protein by a delay of only 10 days past the most desirable stage of harvest.” 

High-quality hay harvest must start at an early growth stage, such as late boot to very early head in grasses and late bud to early bloom in legumes. When hay is baled, moisture content should not be higher than 18 to 20 percent. At higher moisture levels, bales lose large amounts of dry matter caused by excessive heating and molding.

“Start mowing after the dew has dried,” says Ed Rayburn, University of West Virginia. “When the weather is warm, early cut hay will dry to a point that reduces nighttime respiratory loss of total nonstructural carbohydrates. Set the mower to make as wide a swath as possible. This exposes more of the forage to the drying effects of the sun and wind.”

“Value in tedding is to turn the swath and allow forage that was on the bottom or in clumps to come to the top and dry better, resulting in more uniform drying and reducing wet spots in the hay,” Rayburn says. “In most cases, hay should be tedded once in the morning after mowing and after the dew has dried, while the hay is tough. This timing reduces leaf and nutrient loss. If the mower cannot be set to get an open swath, tedding the morning of mowing may be warranted.”

Stop storage losses

If hay is baled with 20 to 22 percent moisture content and stored inside, it should not lose more than 5 percent of its original dry matter during the first year of storage. The hay will lose very little of its digestible nutrients during that time or in succeeding years. An exception is some loss of carotene after the first year. Carotene is the precursor of vitamin A.

“Large bales stored outside will suffer variable losses, depending upon a combination of factors,” Henning says. “These factors are hay moisture at baling, amount of rain and snow during the storage period, internal drainage of the soil on which bales are stored, amount of space between bales, type of hay (grass or grass-legume) and skill of the person operating the baler.”          

When nutrient quality of hay is not preserved, deficits in nutrition need to be filled with higher-priced protein supplements, or corn if TDN (energy) is lacking. Otherwise animal performance will suffer.

Fears is a freelance writer from Georgetown, Texas.