【作者】 丁一；

【导师】 顾洪如； 沈益新；

【作者基本信息】 南京农业大学 ， 草业科学， 2007， 硕士

【摘要】 2005年4月至2006年12月在江苏省农业科学院畜牧研究所试验地对从日本引进的柠檬草(Cymbopogon citratus)进行生长特性调查、施氮对生长的影响以及作为奶牛饲料添加料对牛奶风味和品质影响的实验，得到以下试验结果。1、柠檬草在南京地区只能进行营养生长和营养繁殖利用。柠檬草是多年生热带草本植物，在南京地区的越冬率为24～28％，具有较好的适应性和越冬性。柠檬草还具有较好的耐盐性(Nacl)，1％浓度的盐分胁迫下，柠檬草的株高为对照的61.6％，叶绿素a和b的含量为3.822和3.203mg／g。2％盐浓度胁迫下，柠檬草的株高为对照的36.8％，叶绿素a和b的含量为2.448和3.309mg／g。4％盐浓度胁迫下，柠檬草2周后死亡。随着季节温度的变化，柠檬草精油含量的变化趋势为先升高后降低。从8月13日采样开始至12月12日结束，以8月27日鲜草的精油含量最高，11月27日精油含量开始显著下降，到12月份下降至最低。柠檬草精油含量的日变化为由低到高，然后再降低。精油含量在下午2点温度最高时达到最高值，鲜草精油含量为0.31％，干草精油含量为1.34％。早上8点时精油含量最低，鲜草精油含量为0.25％，干草精油含量为1.07％。2、施氮量为70，140，210，280kgN／hm~2时，柠檬草草产量随着施氮量的增加而增加，施氮有助于柠檬草产量的增加。施氮量为70、140、210、280 kgN／hm~2的鲜草产量分别比对照(不施氮)增加20.8％、58.3％、83.3％、104.2％，干草产量分别增加14.4％、46.8％、67.1％、70.7％。施氮量为70、140、210、280 kgN／hm~2的处理，干草粗蛋白含量分别比对照增加1.3％、2.9％、3.2％、8.9％，施用氮肥可显著改善柠檬草的饲草品质。施氮量为210 kgN／hm和280kgN／hm~2处理间差异不显著，综合精油产量和草产量看，以施氮量210kgN／hm~2最为合适。增施氮肥对柠檬草精油含量和柠檬醛含量影响不显著，但由于施用氮肥使得单位面积柠檬草草产量增加，因此单位面积的精油产量和柠檬醛产量也随施氮量的增加而增加。3、奶牛日粮中添加1.5kg／头柠檬草草粉对牛奶品质无明显影响。经测定，乳脂、乳蛋白、乳糖、总固形物(TS)及非脂乳固体(SNF)等指标，处理和对照间差异均不显著。奶牛日粮中添加柠檬草后的牛奶，经多人品尝，未感觉到牛奶风味有明显改善，但在牛奶中可以检测到柠檬醛存在，含量达0.211μg／kg，说明柠檬醛对牛奶风味的改善仍具有一定作用。奶牛饲喂柠檬草后，血清中SOD活性提高6.97％(P＜0.05)，谷胱甘肽过氧化物酶(GSH-Px)活性提高10.86％(P＜0.05)，显著高于对照，血清MDA含量降低7.94％(P＜0.05)显著低于对照。奶牛日粮中添加柠檬草干草粉1.5kg／头，未出现奶牛因柠檬醛过量中毒现象。且奶牛日粮中添加柠檬草粉可明显提高奶牛血液的抗氧化性，提高奶牛的免疫力，增进奶牛的健康。更多还原

【Abstract】 Field experiments were conducted in Jiangsu Academy of Agricultural Sciences from April 2005 to February 2006 to evaluate forage yield, CP, oil yield and citral contents of lemongrass (Cymbopogon citratus) in response to different nitrogen application rate, and the effect of lemongrass on the flavor of fresh milk was investigated .In 2005, N treatments were applied at five rates of 0、70、140、210、280kgN/hm～2. Replications of one-factor randomize block experiment were established in 2005 field experiments. Four milk cows were randomly divided into 2 groups, treatment group were fed 1.5 kg hay of lemongrass per day. The procedures lasted for 10 days and the anti-oxidation was also investigated. The results are as follows:1. Lemongrass can only be used in vegetative propagation in Nanjing. The over wintering rate of this new-introduced variety is about 24%～28%.It has rather good over wintering ability adaptive ability. It has good salt tolerant (NaCl). Under 1% concentration of salinity stress, the plant height was about 61.6% of that of control, the chlorophyll a and b contents were 3.822 and 3.203. Under 2% concentration of salinity stress, the plant height was about 36.8% of that of control, the chlorophyll a and b contents were 2.448 and 3.309. Under 4% concentration of salinity stress, lemongrass died after two weeks. With the change of season, the content of lemongrass essential oil changed. The content of lemongrass essential oil increased at first and then gradually decreased. The data sampling was from 13 Aug. to 13 Nov. The highest essential oil was at 27 August. The difference of descend range was not significant from 27 Aug. to 13 Dec. Until 27 Dec., the difference of descend range was significant. The highest content of lemongrass essential oil was at 2:00 P.M., the trend of lemongrass essential oil was increased at first and then gradually decreased.2. Lemongrass yield increased with the increasing amount of applied N fertilizer. N treatments were applied at five rates of 0, 70,140, 210 and 280kg N/hm~2, compared with the 0kgN/hm~2,the fresh grass yield increased 20.8%, 58.3%, 83.3% and 104.2%. Hay increased 14.4%, 46.8%, 67.1% and 70.7%. After 70,140,210 and 280 kgN/hm~2 treatments, compared with the control, the crude protein content of fresh grass increases were 1.3%, 2.9%, 3.2% and 8.9%, improved the quality of lemongrass as forage. The influence of nitrogenous fertilizer in oil yield, citral contents of lemongrass were no significant difference, but as nitrogen fertilizer can increase the production of lemongrass, the yield of oil and citral also increased in the unit area.3. Adding natural aromatic forage-lemongrass 1.5kg in the milking cow dairy diet, effect of milk flavor was studied. Test of new multiple range indicated there were no significant difference in the butter oil, lactoprotein, lactose, TS and NSF. Citral was detected in milk and about 0.211μg/kg of milk. And lemongrass affect the milk’s flavor. Add natural aromatic forage-lemongrass 1.5kg in the milking cow dairy diet, determination the GSH-Px, SOD, MDA from the milk cow blood serums, the activity of serum GSH-Px was raised 10.86% (p<0.05) to the control, SOD was raised 6.97% (p<0.05) to the control, but MDA declined 7.94% (p<0.05) to the control.更多还原