体外产气法评价榆树叶在反刍动物日粮的应用

Evaluation of utilization of elm leaves in ruminant diet by in vitro gas production method

利用体外产气法探讨不同精粗比下榆树叶与苜蓿、精料间不同配比对饲粮组合效应(Associative effects,AE)的影响。28个饲粮组合培养0、2、4、6、9、12、24、36、48、72 h时记录产气量(Gas production,GP),计算GP72h的AE。72 h后收集上清液及残渣用以测定pH、挥发性脂肪酸(Volatile fatty acids,VFA)、氨态氮(NH3-N)、干物质降解率(Dry matter digestibility,DMD)和有机物降解率(Organic matter digestibility,OMD),计算单项AE指数、综合AE指数。结果表明,80.20.0、60.40.0、60.10.30、50.20.30、50.10.40、40.40.20、40.30.30、30.55.15、30.40.30、20.20.60组GP72h、DMD、OMD、NH3-N含量以及GP、DMD、OMD、TVFA、NH3-N AE值显著或极显著高于同精粗比下其他各组(P<0.05或P<0.01),30.55.15组AE最优。30.55.15、40.40.20、50.20.30、20.20.60、60.10.30、80.20.0组的单项AE指数、综合AE指数最大,组合效果最佳,可按此配比将榆树叶应用于反刍动物饲粮。

This study aimed to determine the associative effects(AE) of 28 feed combinations of concentrate: elm leaves: alfalfa under different concentrate-roughage ratio(C:R) by in vitro gas production method. The 28 feed combinations were incubated. The GP at 0, 2, 4, 6, 9, 12, 24, 36, 48,72 h were recorded and the AE were calculated by GP72h. After 72 h incubation, the incubation fluid and residues were determined pH, volatile fatty acids(VFA) and ammonia nitrogen(NH3-N), dry matter digestibility(DMD), organic matter digestibility(OMD). The single-factor AE index(SFAEI) and multiplefactor AE index(MFAEI) were computed. The results showed that groups 80:20:0, 60:40:0, 60:10:30, 50:20:30, 50:10:40, 40:40:20, 40:30:30, 30:55:15, 30:40:30, 20:20:60 had higher GP72h, DMD, OMD, NH3-N, in addition, higher AE of GP, DMD, OMD, TVFA and NH3-N than those of the other group under the same C:R(P<0.05 or P<0.01), especially groups 30:55:15 was the optimal. The SFAEI and MFAEI of groups 30:55:15, 40:40:20, 50:20:30, 20:20:60, 60:10:30, 80:20:0 were the greatest. It was concluded that the greatest AE occurred when concentrate: elm leaves: alfalfa ratio were 30:55:15, 40:40:20, 50:20:30, 20:20:60, 60:10:30, 80:20:0. Elm leaves can be used in ruminant diets according to the proportions.