欧美107杨伐根嫁接法造林技术与效果分析

在采伐迹地上,以意大利214杨的伐根做砧木,欧美107杨的1a生条做接穗,进行嫁接法造林技术试验。结果表明,该法造林具有成本低、适应性强、速生等特点。7a生的伐根嫁接法造林的树木平均胸径18.9cm,平均树高19m,单株立木材积为0.1562m3;而利用植苗法造林的同龄树木平均胸径为7.7cm,平均树高为8.4m,单株立木材积为0.0174m3,差异显著。     

间接法Dot—ELISA检测鸡减蛋综合症抗体的建立及应用研究

应用ＳｅｐｈａｄｃｘＧ－２００层析法纯化鸡减蛋综合症病毒，利用ＮＣ膜作为载体，成功建立了检测ＥＤＳ－７６血请抗体的斑点酶联免疫吸附试验（Ｄｏｔ－ＥＬＩＳＡ）。抗原包被浓度为２μｇ／ｍｌ，被检血清浓度为１：２０，酶标兔抗鸡１ｇＧ浓度为１：２００．底物溶液最适ｐＨ值为７．２。对Ａ－Ｆ６个养禽场随机抽检血清１６０份，分别用Ｄｏｔ－ＥＬＩＳＡ、ＨＩ和ＡＧＰ检测，Ｄｏｔ－ＥＬＩＳＡ检出阳性率为５１．９％，ＨＩ检出阳性率为４６．９％，ＡＧＰ检出阳性率为３１．９％。对１４０日龄鸡人工感染试验，测定抗体消长规律。本方法不需特殊仪器。适用于基层兽医部门和养鸡场对ＥＤＳ－７６的血清学诊断和流行病学调查。     

鸡减蛋综合征、新城疫二联灭活油的免疫比较试验及临床应用

本课题组研制的ＥＤＳ／ＮＤ二联灭活苗乳剂苗，免疫接种后产生的ＥＤＳ和ＮＤ的抗体效价分别达到国外进口的ＥＤＳ灭活苗和ＮＤ灭活苗的水平。用本课题组研制的ＥＤＳ／ＮＤ二联灭活苗、Ｉｎｔｅｒｖｅｔ公司和ＴＡＤ公司的ＥＤＳ／ＮＤＭ联灭活苗接种２０周龄的蛋鸡后，ＥＤＳ抗体和ＮＤ抗体的增长曲线无明显差异。在协作场免疫接种了１９群商品蛋鸡，共２０．６万羽，ＨＩ抗体抽测结果为ＥＤＳ抗体峰值达８．０ｌｏｇ２～９．３ｌｏｇ２，ＮＤ抗华峰值达９．０ｌｏｇ２～１０．２ｌｏｇ２，无一群免疫鸡发生副反应，产蛋率正常，有效地控制了ＥＤＳ和ＮＤ的流行。     

冬种甜玉米不同播期与栽培方式比较试验

【目的】为更好地在玉林市推广种植冬种甜玉米,充分利用冬闲田,提高复种指数,增加农民收入。【方法】2008～2009年在玉林市进行冬种甜玉米不同播期和栽培方式的比较试验,收获后进行考种,并进行数据分析。【结果】不同播期和栽培方式对冬种甜玉米穗长、株高、单苞重及产量均有不同程度的影响,播期以早播或迟播较有利于其生长和提高产量;栽培方式以地膜覆盖栽培产量最高。【结论】在玉林市冬种甜玉米华珍76的适宜播期为12月5日,适宜栽培方式为地膜覆盖栽培。     

Freeze-dried vaccine against Rinderpest: Stability and activity study

A freeze-dried vaccine against Rinderpest was prepared from modified virus multiplied in calf kidney cell cutlure. Characteristics of the vaccine are as follows:

• —high titre after freeze-drying (10⁴ CCID₅₀/dose),

• —well-adapted freeze-drying stabiliser which ensures maintenance of the infective titre of the vaccinal virus, even under severe conditions (3.5 days at +45°C),

• —use of an appropriate solvent: magnesium sulphate molar solution or more simply physiological saline (for stability after reconstitution even at high temperatures—up to 4 h at +45°C).

The activity of the vaccine, tested in cattle by antibody titration and resistance to specific challenge perfectly satisfies requirements set by the WHO and OIE.     

A standard vaccine against Marek's disease

HVT-7, the standard vaccine against MD, was prepared from HVT strain FC126 grown in fibroblast cultures from SPF embryos. Ampoules of freeze dried material were prepared from a cell free suspension of virus in a solution of SPGA. The vaccine is stored at −20°C.The primary purpose of the standard vaccine was to control the variation encountered in the assay of virus content of HVT vaccines. The virus content of the standard vaccine was determined under a range of assay conditions, and the method in current use was shown to be satisfactory.A mean value for the virus content of the standard vaccine was determined using a constant assay method, by titrating 27 ampoules over a period of time. A further series of assays performed after one year's storage showed there to be no significant loss of titre.When several ampoules were titrated at the same time, some vial to vial variation was detected, but this was less than normal assay to assay variation.During routine determinations of the virus content of commercial HVT vaccines, an assay of the standard vaccine was carried out simultaneously to determine whether the assay conditions were acceptable. Assays where the value for the virus content of standard vaccine fell outside the expected range were considered invalid.The stability of the standard vaccine after reconstitution in SPGA was considered satisfactory: when reconstituted in phosphate-buffered saline, the rate of decrease in virus content was significantly greater. The vaccine could therefore be used as a control preparation in stability tests.Preliminary investigations showed that the behaviour of the standard vaccine in vivo was similar to that of satisfactory commercial vaccines, so that the preparation may also be of value in tests of vaccines for their ability to produce viraemia and confer protection.     

Treatment of ovine foot-rot by vaccination with the specific aetiological agent Bacteroides nodosus

Accelerated healing of foot-rot cases after vaccination with Bacteroides nodosus confirms the aetiological role of this organism in the disease. There is a variation in the degree of response. It may range from an increased body weight of affected vaccinated sheep to complete resolution of clinical signs and lesions.The degree of response following vaccination is influenced by the adjuvant incorporated in vaccines. Oil emulsion vaccines were superior to aqueous alum-precipitated preparations. A saponin derivative, Quil A, enhanced the effect of alum-precipitated vaccines in a therapeutic experiment.High agglutinin titres to vaccine strains develop in immunised sheep. Recovery from infection has been demonstrated in animals with high agglutinin titres to the immunising B. nodosus but with low titres to the strain of B. nodosus with which sheep were infected. Antibodies other than those directed against the pili of B. nodosus may be involved in the mediation of the demonstrated therapeutic response.     

Anaplasma marginale inactivated vaccine: dose titration against a homologous challenge

The present study was performed to dose-titrate an Anaplasma marginale experimental immunogen derived from partially purified initial bodies from three geographically different Mexican strains. Three five-bovine groups were inoculated twice on days zero and 21 with A. marginale initial bodies equivalent to 1.5×10¹⁰ (group I), 3×10¹⁰ (group II) or 6×10¹⁰ (group III) infected erythrocytes mixed with STDCM® adjuvant. A similar group served as non-vaccinated controls. All four groups were challenged with 1×10⁸ infected erythrocytes from a donor cow with an increasing rickettsemia of strain MEX-15 on day 87 post-vaccination. The prepatent period was very similar for all four groups. All five non-vaccinated controls presented typical acute anaplasmosis syndrome reaching a mean of 30.9% rickettsemia and a loss of 73.4% in the packed cell volume (PCV). Two of five controls died of acute anaplasmosis. Within the vaccinated groups only one animal (group II) suffered acute disease and died. Although all the other vaccinated animals were free of clinical signs, they developed very low rickettsemias (3.2, 3.8 and 4.3%) and PCV losses of 49.9, 47.8, and 49.3% for groups I, II and III. The starting mean weight was very similar for all four groups. All animals lost weight following challenge but losses for groups I and II were lower and significantly different from group IV losses (P0.1). Although there were no significant differences among vaccinated groups, group III was more severely affected. Taken altogether, these results show a 93.3% protection against both illness and death for all groups; and 100% protection for groups I and III, and 80% for group II.     

滴灌下欧美107杨苗高水肥耦合效应

水分和氮肥是影响欧美107杨Populus×eurame ric ana‘74/76’生长的重要因素.以1年生欧美107杨为试验材料,采用田间裂区试验设计,研究不同灌溉、氮施入量对欧美107杨苗高的影响,并建立水—苗高的水肥回归模型.结果表明:不同水肥处理下苗高之间有极显著差异(P＜0.01),各因素效应顺序为氮施入量＞水肥互作＞灌溉量.欧美107杨苗高在300～360 cm的水肥方案为灌溉量8.45～19.25 kg·株-1,施氮肥量4.57～9.12g·株-1,即施尿素413.94～826.31 kg·hm-2;苗高在360～400 cm的水肥方案为灌溉量36.02～41.87 kg·株-1,施氮肥量8.68～ 11.43 g·株-1,即施尿素786.08～1 035.05 kg·hm-2.水肥优化管理方案可为定向培育1年生欧美107杨苗木提供理论依据.     

鸡产蛋下降综合症(EDS—76)灭活油乳剂苗的研究 Ⅱ.不同单位病毒和佐剂的疫苗及和其它同类产品的免疫比较

在本试验中,我们比较了每头份疫苗含不同血凝单位病毒的免疫效果,结果每头份含2000单位和3000单位的病毒疫苗免疫后HI抗体峰值分别为9.2log_2和9.6log_2,而含1000单位病毒的疫苗HI抗体峰值为6.8log_2.油乳剂苗的免疫后抗体效价显著高于氢氧化铝胶为佐剂的灭活苗。