不同牧草在肉羊瘤胃中的降解特性研究

Ruminal degradability characteristics of different forages in sheep

为研究不同牧草干物质(DM)及蛋白质(CP)在肉羊瘤胃中的降解规律,以3头安装有永久性瘤胃瘘管的杜×寒肉用绵公羊为试验动物,采用半体内法对13种牧草的DM和CP的降解率和降解参数进行测定。结果表明:苜蓿DM和CP在瘤胃内各个时间点的降解率最高(P<0.05);沙打旺、狗尾草、燕麦草、草地早熟禾72h降解率显著高于其他牧草(P<0.05)。13种牧草DM的可降解部分和有效降解率的高低顺序与DM在不同时间点的降解高低顺序类似。豆科苜蓿和沙打旺CP的有效降解率最高(P<0.05);禾本科燕麦草、象草、草地早熟禾和狗尾草CP的有效降解率显著高于其他禾本科牧草(P<0.05)。苜蓿慢速降解部分的降解速率显著高于其他牧草(P<0.05)。由此得出,豆科牧草苜蓿、沙打旺DM和CP的降解率高于禾本科牧草。燕麦草、草地早熟禾、象草、狗尾草的降解率较高;冷地早熟禾、多叶老芒麦、羊草、披碱草的降解率居中;芨芨草、中华羊茅和芦苇的降解率偏低。

In order to investigate dry matter （DM） and protein （CP） degradation rule of different forages, three Dorper× Han crossbred male sheep fitted with permanent rumen fistula were selected to estimate DM and CP ruminal degradability of 13 forages in situ. The results showed as follows, ruminal degradability at various time points of DM and CP of Medicago sativa were highest ; Astragalus adsurgens, Setaria viridis, Arrhe natherum elatius and Poa pratensis were significantly higher than others at 72 hours （P〈0.05）. For 13 forages, potential degradation part and effective degradability of DM showed the similar change law with degrad ability at various time points of DM. CP effective degradability of leguminosae M. sativa and A. adsurgens were highest; gramineae A. elatius, Penniseturn purpureum, P. pratensis and S. viridis were significantly higher than others （P〈0.05）. The rate constant for the slow degradation part of M. sativa was significantly higher than other forages （P〈0.05）. In conclusion, DM and CP ruminal degradability of leguminosae M. sati va and A. adsurgens were higher than gramineae pasture; gramineae A. elatius, P. pratensis, P. purpureum and S. viridis were higher than other 7 forages; Poa cryrnophila, Elymus sibiricus, Leymus chinensis and Elymus dahuricus were in the middle; Achnatherum splendens, Festuca sinensis and Phragrnites australis were low.