关键词: 饲用谷子, 产量, 粗蛋白, 饲料相对值, 饲料分级指数

Abstract: This study was designed to provide relevant information for the development of high-quality forage millet germplasm resources, and support informed breeding developments and guide feed formulation. The agronomic trait analysis included 17 summer-sown varieties of forage millet with measurement of fresh and hay yield, plant height, and stem:leaf ratio, among others. To assess nutritive value, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined for the same 17 varieties. Three evaluation indexes were three used: the classification criterion of legume and gramineous forages in America, the relative feed value (RFV) and the grading index (GI), were also calculated, and the varieties ranked according to these criteria. It was found that: 1) The varieties S2014794, S20151375 and S2014742 had higher fresh and hay yield compared to others (the highest values of fresh and hay yield, respectively, were 37.26 and 18.92 t·ha^-1); hence these varieties could be used as high-yield forage resources. The grain yields of varieties Hudewei 2, Zheng 10 and Z281 were high compared to other varieties, relatively higher, and the fresh and hay yield for these ranked medium to high among the tested cultivars of which were also in the middle and upper level; hence these varieties could be used dual purpose grain and forage production varieties. The varieties S2014907, S20151375, K2908 and K1955 had low stem:leaf ratios; while conversely Heng HN201026 and Hudewei 2 had high stem:leaf ratios, so these traits might indicate special uses for these varieties. Stem:leaf ratio also increased with crop maturity, through heading, grain filling, and seed maturation stages of crop development; Heng HN201026 and Hudewei 2 can be used as high-stalk resources. 2) The CP contents of varieties S2014907 and S2014742 (11.81% and 11.63%, respectively), which were higher (P<0.01) than other varieties. The contents of NDF in Zheng 10 and Jinlügu were 39.95% and 40.06% respectively, which were extremely significantly (P<0.01) lower than other varieties. The content of ADF in Sicao 4 was 14.73%, extremely significantly (P<0.01) lower than other varieties. There were different results by three grading methods of forage, but the general trend were same. By the classification criterion of legume and gramineous forages in America, the feeding value of forage millet is middle and upper level, and it is a better forage variety. The GI forage grading values were generally one unit lower than the corresponding RFV values. Based on the three grading methods, the feeding value of Zheng 10, K3970, Jinlügu, Sicao 4, K359, K2908, YC264 and Jicaogu 1 were superior to others, so these varieties could be used as high-nutritive-value resources.

Key words: forage millet, yield, crude protein, relative feed value, grading index