Uncovered hay is vulnerable to spoilage, toxic mold growth, and loss of valuable feed..Without proper cover, hay is exposed to moisture from rain, snow, and high humidity, which can cause it to become damp and promote mold growth.
This not only reduces the hay's nutritional value but may make it unsafe for livestock consumption. Since moldy hay must be disposed of and replaced with high quality hay, this can increase feed costs significantly. In addition, uncovered hay exposed to sunlight often losts essential nutrients and becomes unpalatable to livestock.