Growth Characteristics Of Lemongrass And Effect Of Using As Natural Plant On Diary Cows Feeds Additive

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.