【作者】 闫贵龙；

【导师】 孟庆翔；

【作者基本信息】 中国农业大学 ， 动物营养与饲料科学， 2005， 博士

【摘要】 采用化学成分分析、活体外消化率测定、活体外瘤胃微生物动态发酵产气量测定以及绵羊饲养试验等研究手段,研究了包括作物品种、成熟期、施肥、植侏部位等在内的作物学因素对作物秸秆主要化学成分和活体外消化率的影响以及尿素—氢氧化钙复合处理对于改善作物秸秆营养价值的效果。 试验一,用两个高油玉米品种(HOC647和HOC298)、两个普通玉米品种(CAU80 and CAU 3138)和—个饲料专用玉米品种(FC)作为试验材料,研究了不同玉米类型对秸秆养价值的影响。结果表明,籽粒成熟后,高油玉米秸秆的水溶性糖、淀粉和粗脂肪含量以及干物质、NDF、ADF消化率和48小时产气量,分别比普通玉米秸秆高18.8倍、2.5倍、1.0倍、38.3%、21.4%、25.6%和51.8%(P<0.001),而NDF、ADF和木质素含量分别比普通玉米秸秆低27.3%、32.0,/和39.7%(P<0.001)。高油玉米秸秆的营养价值不仅远高于普通玉米秸秆,而且也远高于饲料专用玉米秸秆。可见,籽粒成熟后的高油玉米秸秆具有营养物质含量高和消化率高的特点,是反刍动物理想的粗饲料和青贮饲料原料。 试验二,以“农大108”玉米秸秆为试验材料,开展的玉米植株不同部位(叶片、叶鞘、茎皮、茎髓、茎常、苞叶)营养价值的比较结果表明,秸秆各部位间的化学成分、活体外消化率和产气量均存在显著或极显著差异(P<0.05或P<0.01),其中总糖含量以茎节、茎皮中最高,分别为20.7%、19.3%;粗脂肪含量在茎节和茎皮中最高,分别为5.80/和5.2%,而茎髓中最少;粗蛋白质含量以叶片中最高(14.9%),而苞叶中最少(6.9%);粗灰分、Ca和P含量均以叶片中最高,分别为10.5%、1.03%和0.1%;NDF在苞叶中含量最高(77.1%);ADF和木质素含量均以茎皮中最高,分别为52.0%、14.4%,苞叶中最低,分别为38.2%、6.7%。DM、NDF和ADF消化率以及最大产气量均以苞叶为最高,其次是叶片、茎髓、茎节和叶鞘,最低的是茎皮。可见,玉米秸秆各部位的营养价值存在明显差异,对其从高到低的排序为:苞叶>茎髓>叶片>叶鞘>茎节>茎皮。 试验三,以两个高油玉米品种(HOC 298和HOC 647)、两个普通玉米品种(CAU 80和CAU 3138)和一个饲料用玉米品(FC)为试验材料,研究籽粒成熟期(1/2、3/4和4/4乳线期)对玉米秸秆主要营养成分含量和干物质、纤维组分消化率的影响。结果表明,随籽粒成熟度提高,高油玉米秸秆的水溶性糖、淀粉、粗脂肪含量和干物质、NDF消化率呈线性规律提高(L;P<0.01),而NDF、ADF和本质素含量则直线规律下降(L;P<0.001),其中,4/4乳线期的水溶性糖、淀粉含量和干物质消化率分别比1/2乳线期提高26.5倍、2.4倍和22.7%,而NDF、ADF和木质素含量分别比1/2乳线期减少24.1%、30.6%和38.4%;普通玉米品种秸秆的情况与高油玉米秸秆正相反,而饲料专用玉米秸秆情况则介丁高油玉米秸秆和普通玉米秸秆之间。可见,高油玉米秸秆是一种优质秸秆,随着籽粒成熟度的提高,它的营养成分和价值呈现与其它类型玉米秸秆完全不同的变化规律。 试验四,用目前生产中普遍种植的青饲玉米品种白马牙(Zea mays L.)的秸秆作为试验材料,研究追施氮肥对玉米秸秆营养价值的影响。结果表明,随着追施尿素量的增加,氨基酸总量、非必需氨基酸总量和粗蛋白、真蛋白、各种必需氨基酸、Ca含量呈线性规律提高(L;P<0.001),而粗脂肪、ADF和木质素含量则均不受影响(P>0.05):尿素追施量小于75kg/ha时,总糖含量随尿素量的提高而增加,尿素量为75～450kg/ha时,总糖含量随尿素量的提高而减少。追施尿素能提高玉米秸秆的干物质、CP、NDF和ADF的消化率,但尿素追施量大于300kg/ha时,这种效果不再提高。用不同尿素追施量的青贮更多还原

【Abstract】 Using chemical analysis, in vitro two-stage digestion and in vitro gas production and sheep feeding trials, five experiments were conducted to study the effect of botanic factors including crop variety, maturity stage, N fertilizer administration, plant position, on main chemical components and digestibility of crop residues, and to evaluate the response of lamb growth performance to the treatment with chemical combinations.In Expt 1, Com stalks from two varieties of high oil corn (HOC; 647 and 298), two varieties of typical corn (CAU 80 and CAU 3138) and one specific fodder corn (FC) were used as substrates in an in vitro fermentation experiment to examine the effect of corn types on the nutritional value. The result showed that HOC stalks harvested even at 4/4ML stage had 18.8,2.5 and 1.0 folds of water soluble carbohydrates (WSC), starch and crude fat higher (P<0.001) than typical corn stalks. The in vitro digestibility of DM , NDF and ADF, and gas production(48h) were 38.3%, 21.4%, 25.6% and 51.8% higher (P<0.001) for HOC stalks than typical com stalks. In comparison with typical com stalks, HOC stalks decreased the contents of NDF, ADF and lignin by 27.3%, 32.0% and 39.7% (P<0.001). The digestibilities of DM, NDF and ADF were not only much higher for HOC stalks than those of typical com stalks, but also much higher than those of specific fodder cornstalks, indicating that HOC stalks would be regarded as an ideal fodder or ensilage material for feeding ruminant animals.In Expt 2, using corn stalks from variety Nongda 108 as an experimental material, the six sections (leaf blade, leaf sheath, stem bark, stem pith, stem node, ear husk) were compared for their nutritional value. The result showed that there was significantly difference (P<0.05) in the chemical composition, in vitro digestibility and gas production of different sections. The stem nodes and barks had highest content of total carbohydrates (20.7% and 19.3% respectively) and of ether extract (5.8% and 5.2% respectively), while the stem pith had the lowest content of ether extract The content of crude protein was highest in leaf blades (14.9%), and lowest inear husks (6.9%). The contents of ash, Ca and P were all highest in leaf blade (10.5% 1.03% and 0.1% respectively). Although a highest content of NDF was found in ear husks (77.1%), the highest content of ADF and lignin was present in stem barks (52.0% and 14.4% respectively) and the lowest was in ear husks. The ear husks had highest the in vitro digestibilities of dry matter, NDF and ADF, and maximum gas production, followed by leaf blades, stem piths, stem nodes, leaf sheaths and stem bark. It was concluded that the various sections of com stalks are significantly different in the nutritive values, with the rank from highest to lowest being as follows: ear husks > stem piths > leaf blades > leaf sheaths > stem nodes > stem barks.In Exp. 3, using two varieties of high oil com (HOC; HOC 647 and HOC 298), two varieties of typical com (CAU 80 and CAU 3138) and a specific fodder com (FC) as experimental materials, the effects of maturity stage of kernels (1/2,3/4 and 4/4 milk line) on nutrient content and in vitro digestibility of com stalks were investigated. The results showed that as the com kernels matured, HOC stalks had linear increases (L; P<0.01) in the content of WSC, starch, and crude fat, and DMD and NDFD, but had a linear decrease in the content of both NDF, ADF and lignin (L; PO.001). Compared with the kernel maturity stage at 1/2 milk line, the 4/4 milk line maturity increased the content of WSC and starch, and dry matter digestibility by 26.5 folds, 2.4 folds and 22.7% but reduced the content of NDF, ADF and lignin by 24.1,30.6 and 38.4% respectively. With increasing the maturity stage of corn kernels, typical com stalks, however, showed an opposite change in chemical contents and nutrient digestibilitiesin contrast to HOC stalks. The results of this experiment indicated that the high oil com stalks are a good corn stalk source for animal feeing.In Exp. 4, com stalks from Zea mays L, were se更多还原