牧压和肥力对亚热带山地牧草净生产的影响

在亚热带山地湿润环境条件下,研究牧压和土壤肥力对人工草地净生产的影响.三年试验结果表明,绵羊在轮牧下,产草量和磷肥对全年及各月牧草净生产具有显著影响.禁牧时,夏季地上生物量积累到一定程度后,只有很少量的净生产.放牧时,产草量在1000 kg DM/hm2左右时,净生产最大,当产草量低于300 kg DM/hm2以下时,净生产量则降低.每年施一次P2O5 36～60 kg/hm2,可以显著增加牧草净生产,尤以春末夏初时施肥更为显著.最低产草量出现在不施肥处理.     

Effect of Split Nitrogen Application on Growth and Yield of Wheat (T. aestivum L.) Genotypes with Different N-Assimilation Potential

A field experiment was conducted with different nitrogen regimes to assess the growth and yield performance of wheat genotypes which differ in nitrate assimilation potential. Genotypic differences in biomass accumulation were observed at different growth stages. The nitrogen treatment had little effect on biomass accumulation at early stages of growth, while at later stages of growth there was enhanced biomass accumulation when N was applied in more than two splits. On an average, genotypes with high nitrate reductase activity (the 'HNR' genotypes) accumulated 14.2 % more biomass than the genotypes with low nitrate reductase activity ('LNR' genotypes) when an extra dose (40 kg N ha⁻¹) of nitrogen was given at the time of anthesis. The application of nitrogen in more than two splits increased grain yield of both 'HNR' and 'LNR' genotypes mainly by increasing grain weight per ear. The application of an extra dose of nitrogen (40 kg N ha⁻¹) at the time of anthesis increased grain yield of 'HNR' genotypes by 38.5 % as compared to 'LNR' genotypes.     

Stoffbildung, CO2-Gaswechsel, Kohlenhydrat- und Stickstoffgehalt von Winterweizen bei erhöhter CO2-Konzentration und Trocken-streß

Dry Matter Production, CO₂ Exchange, Carbohydrate and Nitrogen Content of Winter Wheat at Elevated CO₂ Concentration and Drought Stress
Methods of mathematical modelling and simulation are being used to an increasing degree in estimating the effects of rising atmospheric CO₂ concentration and changing climatic conditions on agricultural ecosystems. In this context, detailed knowledge is required about the possible effects on crop growth and physiological processes. To this aim, the influence of an elevated CO₂ concentration and of drought stress on dry matter production, CO₂ exchange, and on carbohydrate and nitrogen content was studied in two winter wheat varieties from shooting to milk ripeness. Elevated CO₂ concentration leads to a compensation of drought stress and at optimal water supply to an increase of vegetative dry matter and of yield to the fourfold value. This effects were caused by enhanced growth of secondary tillers which were reduced in plants cultivated at atmospheric CO₂ concentration. Analogous effects in the development of ear organs were influenced additionally by competitive interactions between the developing organs. The content and the mass of ethanol soluble carbohydrates in leaves and stems were increased after the CO₂ treatment and exhausted more completely during the grain filling period after drought stress. Plants cultivated from shooting to milk ripeness at elevated CO₂ concentration showed a reduced response of net photosynthesis rate to increasing CO₂ concentration by comparison with untreated plants. The rate of dark respiration was increased in this plants.     

几种代表性牧草对水牛泌乳高峰期生产性能的影响

将36头泌乳期、产奶量相近的水牛均分3组,探讨禾本科黑麦草、豆科紫花苜蓿、蓼科鲁梅克斯K-1三种牧草对泌乳高峰期生产性能的影响,结果发现,饲喂鲁梅克斯K-1分别比紫花苜蓿和黑麦草提高15.93%、13.14%的产奶量(P<0.05),以及6.09%、6.63%的乳脂率(P<0.01);而紫花苜蓿与黑麦草间差异均不显著(P>0.05)。故种植鲁梅克斯K-1适合我国农村散养水牛的小区放牧或舍饲补饲。     

体外产气法评定反刍家畜饲草料营养价值的研究前景

阐述了体外产气法的原理、影响体外产气量的因素及其研究前景。     

Development of Immune Response to Experimental Bovine Trichophyton vervucosum Infection

Abstract— Cell mediated and humoral immune responses to experimental Trichophyton verrucosum infection were assessed by sequential cutaneous biopsies, antibody assessments and microscopic monitoring of fungal presence. Histopathologic examination showed the accrual of lymphocytes and other inflammatory cells in the dermis of infected sites. Immunoperoxidase staining of frozen sections with monoclonal antibody preparations revealed an influx of macrophages, BoCD4+ and B0CD8+ lymphocytes and γδ T cells from the 5th day to the 33rd day of infection. A moderate influx of B cells was observed. Protein G-colloidal gold staining revealed the presence of immunoglobulins in the dermis and superficial epidermal layers. Trichophyton specific serum antibodies appeared between days 33 and 55. Microscopic assessment of infected tissues revealed an increase in T, verrucosum elements (mycelium and ectothrix spores) from days 19 to 55. Fungal elements in infected areas did not decrease until after both humoral and cell mediated elements of the immune response were established. These responses imply a combination of cell mediated and humoral events were associated with T. verrucosum immunity and clearance in the calf. Résumé— Le réponse immunitaire humorale et cellulaire a une infection expérimentale àT. verrucosum a été appréciée par des biospsies cutanées successives, des dosages d'anticorps et la recherche microscopique de champignons. L'examen histopathologique a montré un afflux de lymphocytes et d'autres cellules inflammatoires dane le derme des sites infectés. Les marquages en immunopéroxydase par un anticorps monoclonal de coupes congelées a montré un influx de macrophages, lymphocytes BoCD4+ et BoCD8+ et des cellules T γδ, du 5e au 33e jour de l'infection. Un marquage par une protéine G—or colloidal a révélé d'immunogolglobulines dans le derme et les couches supéerficielles de l'épiderme. Les anticorps spécifiques de Trichophyton sont apparus entre 33 et 55 jours. L'examen microscopique des tissus infectés a révélé une augmentation du nombre d'éléments de T. verrucosum (mycelium et spores ectothrix) du 19e au 55e jours. Les éléments fongiques dans les zones infectées n'ont pas diminué avant que les réponses humorales et cellulaires ne solent établies. Ces résponses impliquent qu'une coopération des réponses humorales et cellulaires étaient associées dans l'immunité et la défense contre T. verrucosum. Zusammenfassung— Die zellvermittelten und humoralen Immunantworten auf die experimentelle Infektion mit T. verrucosum wurden durch eine Serie von Hautbiopsien, Antikörperuntersuchungen und mikroskopischer Untersuchung auf das Vorhandensein von Pilzen ausgewertet. Die histopathologische Untersuchung zeigte eine Ansammlung von Lymphozyten und anderen Entzündungszellen in der Dermis der infizierten Stellen. Die Immunperoxidasefärbung der Gefrierschnitte mit monoklonalen Antikörperzubereitungen zeigte einen Influx von Makrophagen, BoCd4-und BoCD8-Lymphozyten und gamma-delta-T-Zellen vom 5. bis zum 33. Tag der Infektion. Es wurde auch ein mäßiger Influx von B-Zellen beobachtet. Die Protein-G-kolloidale Goldfärbung zeigte die Anwesenheit von Immunglobulinen in der Dermis und den oberflächlichen epidermalen Schichten. Trichophyton-spezifische Serumantikörper traten zwischen Tag 33 und 55 auf. Die mikroskopische Untersuchung infizierter Gewebe zeigte eine Zunahme von T. verrucosum-Bestandteilen (Myzel und exktothrixe Sporen) vom Tag 19 bis 55. Pilzteile in infizierten Bereichen verminderten sich weder, nachdem humorale, noch nachdem zellvermittelte Elemente der Immunantwort auftraten. Diese Reaktionen deuten an, daß eine Kombination von zellvermittelten und humoralen Vorgängen im Zusammenhang mit T. verrucosum-Immumtät und Abheilung beim Kalb vorliegt. Resumen Por medio de biposias cutáneas secuenciales, medida de anticuerpos y exámen microscópico de presencia de hongos, se estudió la respuesta inmunitaria de tipo humoral y celular producida por la infección experimental con T. verrucosum. El exámen histopatológico reveló la presencia de agregación de linfocitos y otras células inflamatorias procedentes de la dermis de los puntos infectados. La tintura por medio de inmunoperoxidasa de las secciones congeladas, con preparaciones monoclonales de anticuerpos, demostró un aflujo de macrófagos BoCD4 + y BoCD8 + linfocitos y linfocitos, Tαδ, desde el quinto hasta el día 33 la infección. También se observó un aflugo moderado de linfocitos B. La tintura aúrica de proteina coloidal G reveló la presencia de inmunoglobulinas en al dermis y capas superficiales de la epidermis. Los anticuerpos específicos para la especie Trichophyton aparecieron entre los días 33 y 55. El exámen microscópico de los tejidos afectados demostró un incremento, de los elementos füngicos T. verrucosum (micelio y esporas exótricas) desde los días 19 al 55. Los elementos fúngicos en áreas infectadas no disminuyeron hasta después del establecimiento de ambos tipos de respuesta inmunitaria, humoral y celular. Estas respuestas implican que la combinación de ciertos fenómenos de inmunidad celular y humoral, están relacionados con la desaparición y la inmunidad de la infección producia por T. verrucosum en el ternero.     

高压电压互感器的可靠性数据统计分析

本文根据高压电压互感器现场运行的调查材料,用概率统计的方法求出其寿命函数,并估计其平均故障率,为高压电压互感器的可靠性管理提供依据和参考。     

浙农大A系意蜂生产性能考察试验报告

用杂交一代蜂群进行对比试验的结果表明,浙农大 A 系意蜂的产育力、群势增长速度、采蜜量等,与平湖意蜂和澳大利亚意蜂无显著差异或基本一致,但蜂王浆高产性能表现突出,产量比平湖意蜂高19.5%,比澳意高42.5%,而且质量指标符合国家规定和出口标准。     

复合酶高活性酵母对岭南黄肉鸡生产性能的影响

300只岭南黄肉鸡随机分为2组(每组设3个重复,每个重复50只),对照组饲喂基础日粮,试验组在基础日粮中用3%活性酵母替代3%豆粕。饲养试验结果表明:0～49日龄,平均末重、平均日增重、成活率试验组分别比对照组提高8.74%(P<0.05)、8.91%(P<0.05)和5.00%(P<0.05),试验组料蛋比比对照组下降11.25%(P<0.05)。代谢试验表明:能量表观利用率和粗蛋白质表观利用率试验组比对照组分别提高4.05%(P<0.05)和6.84%(P<0.05)。