Ruminal degradation of elephant grass silages added with faveira pods

ABSTRACT. The objective of this study was to evaluate in situ ruminal degradability of elephant grass silages with addition of 8, 16 and 24% of faveira pods in experimental silos of 100x50 mm, equipped with bunsen valves. The content of crude protein (cp) and neutral detergent fiber (ndf) were determined on a dry matter basis. To evaluate the in situ degradability of dm, cp and ndf, nylon bags containing 4 g sample were incubated in the rumen of three fistulated cattle for 6, 24 and 72h. The dm and cp content of elephant grass silages increased (p < 0.05) from 8% inclusion associated with a higher concentration of constituents in faveira pods (77.25 and 9.61% dm). The ndf fraction reduced 10.91% (p < 0.05) when adding 24% pods. The potential degradation (pd) of dm and cp increased with inclusion of faveira pods, with 75.97 and 95.21%, respectively, for the level of 24%. There was increased potentially degradable fraction (bp) of ndf by 7.07% with inclusion of 24% faveira pods, as well as a reduced colonization time (lag) from 3.81 to 3.44 hours. The addition of up to 24% faveira pods to elephant grass silages improves rumen microbial degradation, and it is indicated this level of addition to obtain better quality silage.

摘要。本研究旨在在配备本生阀（Bunsen valves）的100×50 mm实验青贮窖中，评估添加8%、16%及24%猴耳环荚（faveira pods）的象草青贮料的原位瘤胃降解特性。以干物质（dry matter, DM）为基础，测定粗蛋白（crude protein, CP）与中性洗涤纤维（neutral detergent fiber, NDF）的含量。为评估DM、CP及NDF的原位降解特性，将每份4 g的样品装入尼龙袋，于3头带瘤胃瘘管的牛（fistulated cattle）的瘤胃中分别培养6 h、24 h及72 h。随着猴耳环荚添加比例提升至8%，象草青贮料的DM与CP含量显著升高（p < 0.05），且猴耳环荚中的组分浓度更高（DM占比77.25%、CP占比9.61%）。当添加24%的猴耳环荚时，NDF组分含量降低了10.91%（p < 0.05）。随着猴耳环荚添加比例提升，DM与CP的潜在降解率（potential degradation, PD）随之升高，在添加比例为24%时分别达到75.97%与95.21%。当添加24%的猴耳环荚时，NDF的潜在可降解组分（potentially degradable fraction, Bp）提升了7.07%，同时定殖滞后时间（lag）从3.81 h降至3.44 h。向象草青贮料中添加最高24%的猴耳环荚可改善瘤胃微生物降解特性，该添加比例可用于制备更高品质的青贮料。