Effect of Moisture Content at Baling on Nutritive Value of Alfalfa Orchardgrass Hay in Conventional and Large Round Bales

Abstract

Alfalfa-orchargrass herbage was harvested for hay at 23, 18, and 13% moisture and stored in conventional and large round hay bales. After 5 mo of storage indoors, hay was higher in acid detergent insoluble nitrogen if baled at 23 than at 18% moisture. This was due to increased internal temperature of the bales, which reached a peak of 90°C at the center of large bales stored at 23% moisture. Acid detergent fiber and acid insoluble lignin increased in hay at the center of round bales compared with the outer layer or shell or that in conventional bales. In vivo digestibilities of dry matter, protein, and acid detergent fiber were significantly reduced in the inside core and outside shell of large round bales stored at 23% moisture compared with conventional bales of equal moisture content. Protein digestibility was depressed only slightly in the core of hay stored in large round bales at 18% moisture. These data show that round bales are more susceptible to heat damage than conventional bales made at the same moisture content.