Dry Matter Yield, Chemical Composition, and In situ Degradability of Extremely Late Maturing Guineagrass (Panicum maximum Jacq. cv. Umaku) with Different Growing Periods

Abstract

The aim of the present study was to evaluate the dry matter yield (DMY), chemical composition, and ruminal degradability of extremely late maturing guineagrass cultivar ‘Umaku’ with different growing periods in a warm temperate zone, compared with rhodesgrass. The ‘Umaku’ and rhodesgrass cultivar ‘Katambora’ were sown in late July in a farm field (Koshi, Kumamoto, Japan), and were harvested at 60, 75, and 90 days after seeding. The DMY of ‘Umaku’ increased concomitantly with longer growing periods and was always higher than that of ‘Katambora’. Longer growing periods correlated with lower crude protein and higher non-fibrous carbohydrate contents, but the neutral detergent fiber contents of the two grass species did not change. Ruminal degradability at the same growing period was identical in the two grasses, and decreased with longer growing periods. The DMY and ruminal degradability of ‘Umaku’ at 60 days were superior to those of ‘Katambora’ at 90 days. These findings indicate that the guineagrass cultivar ‘Umaku’ cultivated in a temperate zone has high potential as a nutritious feedstuff for cattle.