Changes in the Feed Composition Content of Short-Panicle Rice Varieties after Heading in the Western Region of Japan

: This study was conducted in the Western Region Agricultural Center (Fukuyama City, Hiroshima Prefecture) to elucidate the changes in feed composition and contents in rice after heading. In 2007, we cultivated a short panicle cultivar, “Tachi-Ayaka” using two different transplanting times. In 2018, we cultivated four short- panicle varieties with different heading dates: “Tsuki-Hayaka”, “Tsuki-Ayaka”, “Tsuki-Suzuka”, and “Tsuki-Kotoka”. We investigated their top dry weight and their feed composition and contents from heading date to about 70 days after heading. The feed composition and contents varied greatly up to 40 days after heading. Specifically, crude protein (CP) and acid detergent fiber (ADF) decreased, crude ash (CA) and hemicellulose hardly changed; and, non-fibrous carbohydrate (NFC) increased. Top dry weight peaked at 30-40 days after heading in all transplanting times and varieties. Increased in weight between heading and 40 days after heading of NFC, hemicellulose and CA accounted for 71%, 19% and 8%, respectively, of that of top dry weight. We conclude that wide variation in feed composition content up to 40 days after heading was mainly due to the increase in NFC dry weight. The feed composition content was stable from 30 days after heading because the variation in NFC dry weight was very small.