Main Article Content
In this study, 14 kinds of different forage sweet sorghum varieties were used as materials to study the effects of different cutting times on the biological yield and nutrient components of Sweet Sorghum, including the determination of plant height, leaf length, leaf width and other agronomic shapes of different varieties and the nutrients of the whole plant. The results showed that the differences of plant height, leaf length and leaf width were significant (p<0.05) at the same cutting stage, and the water content of each variety was the highest at jointing stage. There was no significant difference between the varieties at booting stage and maturity stage (p>0.05). In booting stage, the content of coarse ash of various varieties changed little, and the content of coarse ash of sweet sorghum decreased in different cutting period. The content of crude fat and carbohydrate was the highest in booting stage, and protein content in each variety increased and then decreased with the extension of growth stage. The content of calcium and phosphorus in each variety was significantly higher than that in booting stage and maturity stage (p<0.05), and the acid detergent fiber and neutral detergent fiber increased with the extension of growth period. In this study, the tannin content of all varieties of sweet sorghum in different cutting periods was low, which would not affect the feed intake of beef cattle. The content of cyanide decreased significantly with the growth of plants (p<0.05), and reached at the highest content in jointing stage. Each variety showed the advantages of good quality and rich nutrition. In production practice, the cutting period can be determined according to the varieties planted.