Livestock specialists at Iowa State University say lab tests show nearly 80% of the hay harvested in Iowa last summer could be energy-deficient. Denise Schwab, with I.S.U. Extension, says the tests involved more than 500 hay samples and the implications are especially critical for pregnant cows.

“We either need to supplement with better quality hay or with energy feed – such as corn, corn gluten or corn distillers grain – in order to provide enough energy for the cow to maintain herself, grow that fetus and be able to rebreed for the next year,” Schwab said. The nutrient-deficient hay is blamed on last summer’s heavy rains which prevented timely harvesting of the grasses. Schwab says the problem has been compounded by this winter’s cold temperatures.

“The harsher the winter, the more energy that’s needed just to maintain that cow – let alone provide for that fetus growing inside her,” Schwab explained, “so this winter, which was very cold through December and January, really made the problem that much worse.” Sheep are also affected and Schwab says many Iowa dairies are importing hay from outside the state.