Stewart W C, Whitney T R, Scholljegerdes E J, Naumann H D, Cherry N M, Muir J P, Lambert B D, Walker J W, Adams R P, Welch K D, Gardner D R, Estell R E
J Anim Sci. 2015 Aug;93(8):4034-47. doi: 10.2527/jas.2015-9274.
Rising feed costs and recurring feed shortages necessitate the investigation into alternative and underutilized feed resources. Nutritional characteristics of species are either unknown or limited to leaves and ground material from small stems. Therefore, the objective was to quantify nutritional characteristics, 48-h true IVDMD (tIVDMD), microbial gas production, and secondary compound characteristics of entire woody plant material of 4 species-, , , and -at immature and mature stages of growth. Immature plants had greater CP concentrations and lower NDF concentrations ( < 0.001) than mature plants regardless of species. Mature plants also had greater ( < 0.001) concentrations of ADF compared with immature plants with the exception of . In general, immature , , and had greater ( < 0.02) tIVDMD and total 48-h and asymptotic gas production than mature plants. Immature and plants were more digested (tIVDMD; < 0.001) than immature and , but tIVDMD did not differ in mature plant material across species. Condensed tannins (CT) were greater ( < 0.001) in immature and than mature plants; differences in CT concentrations among immature species were also detected ( < 0.04). Volatile oil yields were similar across maturity and species with 1 exception: immature yielded more ( < 0.02) volatile oil than mature material. Volatile oil composition across species varied and contained a range of 65 to 70 terpene compounds. The dominant terpenes across species were generally greater ( < 0.05) in immature vs. mature plant material with the exception of . Labdane acids were negligible in , , and and greater in ( < 0.001). Ground material from mature juniper species, although inferior in nutritional quality compared with immature plants, is comparable to traditional low-quality roughage ingredients. Given that has been successfully fed in lamb feedlot diets, the similarities of , and suggest that all three species have potential to be effective roughage ingredients.
饲料成本不断上涨以及饲料短缺反复出现，使得有必要对替代性和未充分利用的饲料资源进行调查。物种的营养特性要么未知，要么仅限于小茎的叶子和粉碎物。因此，本研究的目的是量化4种植物（、、和）在未成熟和成熟生长阶段的全木质植物材料的营养特性、48小时真体外干物质消化率（tIVDMD）、微生物产气量和次生化合物特性。无论物种如何，未成熟植株的粗蛋白（CP）浓度均高于成熟植株，中性洗涤纤维（NDF）浓度低于成熟植株（<0.001）。与未成熟植株相比，除外，成熟植株的酸性洗涤纤维（ADF）浓度也更高（<0.001）。总体而言，未成熟的、和的tIVDMD以及48小时总产气量和渐近产气量均高于成熟植株（<0.02）。未成熟的和植株比未成熟的和更容易消化（tIVDMD；<0.001），但成熟植株材料的tIVDMD在不同物种间没有差异。未成熟的和中的缩合单宁（CT）含量高于成熟植株（<0.001）；未成熟物种间CT浓度也存在差异（<0.04）。除1个例外，不同成熟度和物种的挥发油产量相似：未成熟的挥发油产量高于成熟材料（<0.02）。不同物种的挥发油成分各不相同，含有65至70种萜类化合物。除外，不同物种中占主导地位的萜类化合物在未成熟植株材料中通常高于成熟植株材料（<0.05）。在、和中，半日花烷酸含量可忽略不计，而在中含量较高（<0.001）。成熟杜松属物种的粉碎物，虽然营养质量不如未成熟植株，但与传统的低质量粗饲料成分相当。鉴于已成功用于羔羊育肥日粮中，、和的相似性表明这三个物种都有潜力成为有效的粗饲料成分。
