Hay preparation

Rye hay was made in triplicate after harvesting on April 30 (early boot), May 9 (heading), and May 15 (blooming). The cut down rye was tedded twice each day to shorten the drying process. During the drying process, DM content was checked and recorded twice each day (9:00 and 17:00). After DM content increased more than 80%, the hay was packed into a nylon-net bag (40 × 80 cm, ~2 kg, Doo-il Chemical, Incheon, Korea) and preserved at ambient temperature for 70 days. During storage, variations in the rye hay and air temperatures were recorded at 17:00 every five days using a dial probe thermometer (Daewon Instrument, Seoul, Korea) with a 50-mm diameter dial and 300-mm length stainless probe. After storage, DM loss was calculated.