Vaccination and challenge studies with psittacine beak and feather disease virus     

SR RAIDAL  GA FIRTH†  GM CROSS 《Australian veterinary journal》1993,70(12):437-441

SUMMARY: Psittacine beak and feather disease virus (PBFDV) was administered to adult galahs ( Eolophusroselcapillus ) by mouth or by intramuscular injection. Concentration of PBFDV antibodies in serum and excretion of PBFDV were monitored by haemagglutlnation inhibition (HI) and haemagglutination (HA) respectively. After oral administration, 17 of 18 galahs remained clinically normal and a small rise in antibody titre was detected in 3 of 18 birds. After intramuscular administration, antibody was detected in all birds. PBFDV was not detected in the feather dander of birds in either group. One bird developed diarrhoea and high faecal HA titres within 4 days of oral administration and then died. Adult and nestling cockatoos were vaccinated with an experimental inactivated double-oil emulsion vaccine. PBFDV antibody responses are comparable to those induced by a primary-oil emulsion vaccination regimen using Freund's adjuvants. Both vaccines protected nestlings. Three sibling wild-caught sulphur-crested cockatoos were vaccinated but died of PBFD before experimental challenge despite antibody responses in all birds. Unvaccinated control chicks developed acute PBFD within 4 weeks of challenge, probably from PBFDV-induced hepatitis since high concentrations of PBFDV were detected in their livers.  相似文献   

Constant Light Exposure Causes Dissociation in Gonadotrophin Secretion and Inhibits Partially Neuroendocrine Differentiation of Leydig Cells in Adult Rats     

HH Ortega  JA Lorente  GA Mira  C Baravalle  NR Salvetti 《Reproduction in domestic animals》2004,39(6):417-423

The objective of this work was to study the changes that occur in the Leydig cells of rats exposed to continuous light. The laboratory rat is considered a non-photoperiodic species because exposure to short photoperiod has little or no effect on the reproductive status. However, exposure of adult female rats to constant light induces polycystic ovaries, indicating that extreme changes in the photoperiod affect the reproductive function seriously. Adult male rats were placed under continuous light conditions for a duration of 15 weeks. After this period, the animals were killed and testicles were dissected and processed by routine histologic protocols. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) serum levels were determined by radioimmunoassay (RIA). The visualization of antigens was achieved by the streptavidin-peroxidase immunohistochemical method. Antibodies against chromogranin A, S-100 protein, P substance, synaptofisin, neurofilament protein-200, gliofibrillary acidic protein and neurone-specific enolase were used. The mean LH serum concentration was significantly lower, while the mean FSH level was significantly higher in treated animals. The expression of S-100, NSE, CrA, SP and SYN was significantly lower in treated animals. In conclusion, the constant light exposure acting directly at the pituitary level decreases LH secretion. The increased FSH secretion may be due to a partial reduction of the negative androgen feedback in the pituitary gland. Moreover, the constant light exposure affects the expression of some immunomarkers in Leydig cells, possibly because of the changes found in the gonadotrophin level and feedback mechanism.  相似文献   

马尾松半同胞家系子代林早期生长差异分析     

胡云  胡泽军  高大雄  朱玫  宋亚莉  肖宋高  王珍  周欢  张卓文 《福建农林大学学报(自然科学版)》2012,41(4):493-497

以湖北省京山县太子山林场管理局马尾松无性系嫁接种子园半同胞8年生子代林为研究对象,在对胸径、树高、枝下高、冠幅和材积等生长因子进行实地调查的基础上进行遗传力分析.结果表明:不同半同胞家系林木各生长因子之间存在极显著性差异,显示马尾松半同胞家系林木间存在较为丰富的遗传变异,具有较大的选育潜力;8年生马尾松半同胞家系子代林树高、胸径和材积的遗传力分别为0.7436、0.6055和0.6500;采用20%的入选率时,筛选出5个优良半同胞家系且入选半同胞家系的材积、树高和胸径遗传增益分别为51.34%、17.45%和22.19%.  相似文献   

玉米的不同温度和时间烘烤加工处理对泌乳奶牛瘤胃干物质和淀粉降解规律的研究     

齐智利  嗄尔迪  陈慧君  赵芙蓉  尹福泉  刘瑞芳 《畜牧兽医学报》2006,37(7):667-671

以3头安装永久性瘤胃瘘管的泌乳前期荷斯坦奶牛为试验动物，在精粗比为55：45的日粮条件下，采用In sacco法测定了不同温度和时间烘烤加工处理的玉米在奶牛瘤胃内干物质和淀粉的降解规律。结果表明，玉米经过不同温度和时间的烘烤处理，干物质和淀粉的瘤胃降解率都有不同程度的降低，随着温度逐渐升高、作用时间逐渐延长，干物质和淀粉的降解率也逐渐降低。在所有处理组中，140℃35min处理组可以明显降低玉米的瘤胃淀粉降解率（P〈O．05），比未处理玉米组降低了15．26％。淀粉在瘤胃中降解的影响因素最主要的是淀粉的快速可溶部分和降解速率。  相似文献   

阿克苏引种面包小麦济南17号超高产栽培初探     

张卫东  秦勇  赛买提  古拉音  张巨松 《新疆农业科学》2005,42(Z1):22-24

阿克苏地区2000-2001年从山东省农科院引进强筋面包小麦新品种济南17号,在地区农业试验站进行品种区域适应性比较试验,并对其生育和植株性状进行了观测,在参试的8个品种中,济南17号平均产量6804kg/hm2,位居第三,较对照邯5316(地区小麦主栽品种)增产840kg/hm2,增产率14%。2001-2002年又在地区农业试验站对该品种示范种植800.04m2,产量8550kg/hm2,首次实现本地区引种面包小麦单产超8250kg/hm2的产量水平,两年试验示范结果表明,该品种在阿克苏地区具有较强的适应性和丰产性,同时取得了实现强筋小麦济南17号高产栽培的实践经验。  相似文献   

Efficacy of a novel copper-based footbath preparation for the treatment of ovine footrot during the spread period     

GA REED  DU ALLEY 《Australian veterinary journal》1996,74(5):375-382

Objective: To determine the efficacy of a novel copper based footbath preparation (CHF-1020) for treatment of ovine footrot during the spread period.
Design: A series of field trials with treated and control groups run together.
Animals: Mobs of at least 125 sheep on each of six properties in southern New South Wales with equal numbers of controls.
Procedure: Sheep of group A were treated after minimal paring by making them stand in CHF-1020 for 15 minutes. Treatment was undertaken at intervals throughout the period of the trials (14 September to 17 December 1993). Group A sheep were run on the same pasture as those from group B (untreated sheep).
Results: The percentage of sheep exhibiting clinical signs of ovine footrot at the start of the trial ranged from 35 to 88% at score 3 or higher, using a 0 to 5 footscoring system. During the trial, the percentage of infected sheep (greater or equal to score 2) in group B increased and ranged from 40 to 90%. The level of infected sheep in group A on each property was reduced progressively to 1 to 16%. Cure rates of 45 to 94% were achieved, with the lowest rate being on a property with a metal footbath. The next lowest cure rate was 73%. Results indicated that treatment should be undertaken at 2-weekly intervals while spread continues. Treated sheep can be returned to contaminated pastures.
Conclusion: CHF-1020 is effective during the spread period and can be used for the progressive eradication of ovine footrot.  相似文献   

论琵琶演奏音乐语言表现力的多元性     

高微 《湖南农业大学学报(自然科学版)》2009,(2)

从音乐本身出发,从琵琶音乐语言和琵琶音乐表达的技术手段两方面对琵琶音乐语言的表现力作出作者自身的理解.琵琶音乐语言的表现力是多元性的,可以从琵琶音乐语言特性的界定以及琵琶音乐表达的技术手段来了解.  相似文献   

The incidence, cost and factors associated with foot lameness in dairy cattle in south-western Victoria     

DJ HARRIS  CD HIBBURT†  GA ANDERSON‡  PJ YOUNIS†  DH FITSPATRICK§  AC DUNN¶  IW PARSONS  NR McBEATH 《Australian veterinary journal》1988,65(6):171-176

A survey of 73 dairy farms in south-western Victoria was conducted to assess the cost and mean herd incidence of foot lameness for the period from calving to the end of November, 1985, and to identify the herd, management and environmental factors associated with foot lameness. The mean herd size was 125 cows (range 82 to 220). Lameness occurred in 64 (88%) herds, and the mean herd incidence was 7.0% (range 0.0 to 30.9%). The main clinical signs associated with lameness were the presence of overworn and/or bruised soles, or stones lodged in the interdigital cleft. Factors associated with lameness were: property and herd size, age of cow, bail feeding, voluntary entry into the bails, and features of the farm track including its length, the presence of steep slopes, the type of surface material, presence and treatment of broken sections and maintenance including rolling history. The association of these factors with specific clinical signs was examined. The mean cost was estimated to be $42.90 per lame cow due to loss of production, treatment, the culling or death of lame cows, and extra man hours spent managing lame cows. It was concluded that the site, construction, maintenance and use of the farm track were of major importance to the incidence of lameness in herds in this area and recommendations for reducing lameness are made.  相似文献   

Efficacy of Australian vaccines against recent isolates of avian infectious bronchitis viruses     

Y. ARVIDSON  GA TANNOCK  M. ZERBES  J. IGNJATOVIC 《Australian veterinary journal》1991,68(6):211-212

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Effects of antibiotic therapy at drying off on mastitis in the dry period and early lactation     

JW BROWNING  GA MEIN  M. BARTON  TJ NICHOLLS  P. BRIGHTLING 《Australian veterinary journal》1990,67(12):440-442

Four strategies for selecting cows for intramammary therapy with benzathine cloxacillin at drying off were compared in 12 Victorian dairy herds. The bacteriological status of all quarters of all (1044) cows was determined just before drying off, within 2 d of calving, and again 3 to 5 months after calving. All cases of clinical mastitis (from calving to mid-lactation) were recorded. Cows not infected at drying off were allocated randomly to 2 subgroups of approximately 350 cows each: not infected, not treated (NI-NT), or not infected, all quarters treated (NI-AT). New infection rates in the dry period (3.8% for NI-NT vs 2.1% for NI-AT) and in early lactation (4.1% for NI-NT vs 3.9% for NI-AT) were low and these differences were not significant. Incidence of clinical mastitis in early lactation was almost 50% higher for the treated group of uninfected cows compared with the untreated group (0.05 less than p less than 0.1). Cows infected in one or more quarters at drying off were split randomly into 2 subgroups of approximately 170 cows each: infected, all quarters treated (I-AT), or infected quarters treated only (I-QT). The new infection rate during the dry period was nearly 4 times higher for I-QT (15.3%) due to significantly more new infections by Staphylococcus aureus and Streptococcus uberis.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献