J.P. Ames, M.A. Neres, D.D. Castagnara, L.M. Mufatto, C. Ducati, C.C. Jobim, and T.T. Tres. 2014. Dry matter production, chemical composition, dry matter digestibility and occurrence of fungi in Bermuda grass hay (Cynodon dactylon) under different fertilization systems or associated with pea plantings in winter. Cien. Inv. Agr. 41(2): 163-174. This study aimed to evaluate the structural characteristics, dehydration curve, DM production, chemical composition, in vitro dry matter digestibility and occurrence of fungi in Bermuda grass hay (Cynodon dactylon cv. 'Bermuda grass', Tifton 85) produced in winter under different forms of fertilization or in association with a winter annual legume. The experimental design used was a randomized block with split plots in time and with four treatments: Bermuda grass without fertilization or intercropping, Bermuda grass with nitrogen (N) chemical fertilizer (100 kg N ha-'year-1), Bermuda grass oversown with forage pea (Pisum arvense cv. 'Iapar 83'), and Bermuda grass with the addition of 70 m³ ha-1 swine slurry. Three evaluation periods (cutting, baling and 30 days of storage) and five replicates were used. The DM yield of Bermuda grass without N was 2607 kg ha-1. The use of swine slurry increased the DM yield of Bermuda grass more than the use of the N chemical fertilizer (4864 and 3551 kg ha-1, respectively). In association with forage pea, a high total DM yield was obtained: 4261 kg ha-1 of pea and 2171 kg ha-1 of Bermuda grass. The dehydration time and final crude protein content of the Bermuda grass were higher in association with the legume. The levels of acid detergent-insoluble protein increased with storage. The in vitro DM digestibility reduced the cut to 30 days of storage in treatments with Bermuda grass without association with the legume. A higher occurrence of fungi occurred after 30 days of storage, with Penicillium generally predominant; however, Phoma was predominant in the hay produced from Bermuda grass grown with no N supplementation.