Effect of moisture level and bale size on alfalfa hay quality

Abstract

Third cutting alfalfa was baled in large I-ton rectangular bales and in small conventional bales at three moisture levels, low (10%), medium (16%), and high (22%). During 120 days of storage under a roof, the high-moisture, large bales heated the most, reaching 128 ̊ F by 2 days post baling in a first peak and 133 ̊F in a second peak by the 11 th day. Moderate heating occurred in the high-moisture, small bales (l08° F) and medium-moisture, large bales(103 ̊F). Only the high-moisture, small and large bales had significant loss of dry matter during storage. Also, heating decreased the water soluble carbohydrate and increased the concentration of cell wall contents by the 120th day of storage. A three-period collection and digestion trial with lambs showed higher voluntary intakes of small-bale hays than of large-bale hays and higher intakes of high-moisture hays than of low-moisture hays. Also, the dry matter and crude protein digestibilities were lowest for the high-moisture, large bale hay. These data indicate that baling alfalfa hay in large bales at 22% moisture results in extensive heating, which negatively affects storage loss, nutrient content, and digestibility.