Changes in Nutritive Value of Bermudagrass Hay during Storage

Relatively little is known about storage of wet (>200 g kg −1 moisture) bermudagrass [ Cynodon dactylon (L.) Pers.] hay. Our objective was to assess the changes in nutritive value of bermudagrass hay as a function of hay moisture, storage time, and spontaneous heating. ‘Greenfield’ bermudagrass was grown on a Pickwick silt loam soil (fine‐silty, mixed, semiactive, thermic Typic Paleudult) and packaged in conventional rectangular bales at 219, 265, and 302 g kg −1 moisture [low‐moisture (LM), medium‐moisture (MM), and high‐moisture (HM) bales, respectively]. Concentrations of most fiber and fiber‐associated N components increased ( P < 0.05) during storage, but these changes occurred primarily during the first 12 d. A nonlinear model Y = α − β e − kt 2was used to describe the changes in neutral detergent fiber (NDF), acid detergent fiber, lignin, neutral detergent–insoluble N, and acid detergent–insoluble N (ADIN) during storage. The total changes (β) in NDF were 93.1, 69.5, and 67.8 g kg −1 for HM, MM, and LM bales, respectively. Respective asymptotic maxima for NDF (α) in these treatments were 777, 757, and 739 g kg −1 . For ADIN, respective asymptotic maxima (α) reached 3.17, 1.83, and 1.71 g kg −1 for HM, MM, and LM bales, respectively. On Day 65, ADIN exceeded 10% of the entire N pool in both HM and MM bales. The nutritive value of bermudagrass hay baled and stored at >200 g kg −1 moisture deteriorates during storage, and the greatest deterioration occurs during the first 12 d after baling.