Third cutting alfalfa was baled in large rectangular bales (1,400 to 1,800 lb)
and in small conventional bales (70 to 90 lb) at three moisture levels: low 00%),
medium (16%), and high (22%). During 120 days of storage under a roof, the high
moisture, large bales heated the most, reaching 1280 F by 2 days post-baling in a
first peak and 133 ̊F in a second peak by the 11th day. Moderate heating occurred
in the high moisture, small bales (l08° F) and medium moisture, large bales (103 ̊F).
Only the high moisture bales, either small or large, had significant dry matter loss
during storage. Also, heating decreased water soluble carbohydrates and increased
the concentration of cell wall contents by the end 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 bales. Storing alfalfa hay in large bales at 22%
moisture resulted in extensive heating, which increased storage loss and decreased
nutrient content and digestibility.
