Influence of variety and growth period on the nutrient content and in vitro gas production characteristics of Stylosanthes

This experiment was conducted to investigate the influence of variety and growth period on the nutrient content of Stylosanthes guianensis cv. Reyan No. 2, S. guianensis cv. Reyan No. 20, and S. guianensis cv. Reyan No. 21, and the in vitro gas production characteristics. The results showed that S. guianensis cv. Reyan No. 2 had higher content of crude protein(CP)and crude fat(EE) than did S. guianensis cv. Reyan No. 20 and S. guianensis cv. Reyan No. 21 in terms of nutrients, but the in vitro gas production of the three varieties was similar, except for S. guianensis cv. Reyan No. 21, which had lower in vitro dry matter digestibility(IVDMD) and microbial protein content(MCP). Content of some nutrients in Stylosanthes, such as crude protein, acid detergent fiber(ADF), neutral detergent fiber(NDF), and relative feed value(RFV), presented obvious regularity following the growth periods. The content of CP initially increased, subsequently decreased, and reached a maximum in the initial flowering stage. The content of ADF and NDF increased with growth, and RFV gradually decreased. It was concluded that Stylosanthes have a high content of CP and low fibre content, and are high-quality forage for domestic animals. It was also concluded that the vegetative stage was the proper growth period for animal feed.