Some characteristics of a recent virulent isolate of Marek's disease virus   总被引：1，自引：0，他引：1  

M ZERBES  GA TANNOCK  RJ JENNER  PL YOUNG 《Australian veterinary journal》1994,71(1):21-22

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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   

COMMERCIALIZATION OF HARD CLAM (Mercenaria mercenaria) MARICULTURE IN SOUTH CAROLINA: PRELIMINARY REPORT1     

John J. Manzi  Victor G. Burrell  Harry Q. M. Clawson 《Journal of the World Aquaculture Society》1981,12(1):181-195

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CASEOUS LYMPHADENITIS IN GOATS   总被引：1，自引：0，他引：1  

D. H. Burrell 《Australian veterinary journal》1981,57(3):105-110

SUMMARY Two dairy goat stud herds were surveyed for Corynebacterium ovis infection by clinical examination and serum tests using both the haemolysis inhibition and double immunodiffusion techniques for detection of C. ovis antitoxin. In one herd, of 53 goats, 11 had abscesses from which C. ovis was recorded; 33 and 29 goats were positive to the haemolysis inhibition and double immunodiffusion tests respectively. Serums from 10 and 9 of 23 kids gave reactions positive to the respective tests with 19 of the 23 kids having been born to does with demonstrable antibody. In a second herd of 57 goats 16 had superficial abscesses containing C. ovis ; serums from 34 and 45 goats gave positive reactions to the haemolysis inhibition and double immunodiffusion tests respectively. The prevalence of caseous lymphadenitis in these stud herds was a cause of economic loss to the owners through euthanasia of severely affected goats, reduced milk production and emaciation, the cost of labour and drugs for treatment, jeopardisation of income from boarding or mating with outside stock and the appearance of goats at stud shows, and sale of valuable breeding stock to local and export markets.  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   

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   

Isolation of respiratory bovine coronavirus, other cytocidal viruses, and Pasteurella spp from cattle involved in two natural outbreaks of shipping fever     

Storz J  Purdy CW  Lin X  Burrell M  Truax RE  Briggs RE  Frank GH  Loan RW 《Journal of the American Veterinary Medical Association》2000,216(10):1599-1604

OBJECTIVE: To identify cytocidal viruses and Pasteurella spp that could be isolated from cattle involved in 2 natural outbreaks of shipping fever. ANIMALS: 105 and 120 castrated male 4- to 8-month-old feedlot cattle involved in 1997 and 1998 outbreaks, respectively. PROCEDURES: Nasal swab specimens and blood samples were collected, and cattle were vaccinated on arrival at an order-buyer barn from 4 local auction houses. Four days later, they were transported to a feedlot, and additional nasal swab specimens and blood samples were collected. Nasal swab specimens were submitted for virus isolation and bacterial culture; blood samples were submitted for measurement of respiratory bovine coronavirus (RBCV) hemagglutinin inhibition titers. RESULTS: 93 of 105 cattle and 106 of 120 cattle developed signs of respiratory tract disease during 1997 and 1998, respectively, and RBCV was isolated from 81 and 89 sick cattle, respectively, while at the order-buyer's barn or the day after arrival at the feedlot. During the 1997 outbreak, bovine herpesvirus 1 was isolated from 2 cattle at the order-buyer's barn and from 5 cattle 7 and 14 days after arrival at the feedlot, and parainfluenza virus 3 was isolated from 4 cattle 14 days after arrival at the feedlot. During the 1998 outbreak, bovine herpesvirus 1 was isolated from 2 cattle at the order-buyer's barn and on arrival at the feedlot and from 5 cattle 7 and 14 days after arrival at the feedlot, and parainfluenza virus 3 was isolated from 1 animal the day of, and from 18 cattle 7 and 14 days after, arrival at the feedlot. Pasteurella spp was cultured from 4 and 6 cattle at the order-buyer's barn and from 92 and 72 cattle on arrival at the feedlot during the 1997 and 1998 outbreaks, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that RBCV may play a causative role in outbreaks of shipping fever in cattle. More than 80% of the sick cattle shed RBCV at the beginning of 2 outbreaks when the Pasteurella spp infection rate was low.  相似文献   

Conditions for in vitro haemolytic activity by Corynebacterium ovis exotoxin.     

D H Burrell 《Research in veterinary science》1979,26(3):333-338

A substance, concluded to be Corynebacterium ovis exotoxin on the basis of properties shared, was found to have haemolytic activity below pH 6 and red cell adhesion activity at neutral or slightly alkaline pH. An acidified, solid blood agar medium was used to demonstrate the extent of haemolysis that could be obtained at optimal pH and its inhibition by immune serum. Culture in a liquid medium giving rise to a suitably acidic pH allowed titration for haemolytic activity by the exotoxin and use of supernatant in a haemolysis-inhibition test to detect antitoxin.  相似文献   

Responses of broilers to dietary zinc concentrations and sources in relation to environmental implications   总被引：3，自引：0，他引：3  

Burrell AL  Dozier WA  Davis AJ  Compton MM  Freeman ME  Vendrell PF  Ward TL 《British poultry science》2004,45(2):255-263

1. Since high concentrations of zinc are associated with reduced crop yields, environmental concerns are emerging regarding zinc accumulation in areas where poultry production is prevalent. This study investigates growth performance and zinc utilisation during the life cycle of broilers when diets were supplemented with various concentrations of zinc from two different sources. 2. A total of 740 Cobb 500 1-d-old male broiler chicks was randomly distributed into 88 battery cages. Excreta were collected over a 48-h period on d 10, 17, 24, 31, 38, and 45 to measure zinc excretion on a dry matter basis. 3. During the 45-d experimental period, broilers were given a maize-soybean meal basal diet (30 mg/kg zinc) supplemented with 0, 20, 40, and 80 mg/kg of zinc from zinc sulphate, Availa Zn amino acid complex, or an equal combination of zinc sulphate and Availa Zn amino acid complex. 4. Progressive additions of zinc to the basal diet significantly increased body weight gain of broilers, but did not affect feed conversion or mortality. Optimum body weight gain was achieved at 80 mg/kg supplemental zinc, which exceeds the NRC recommendations of 40 mg/kg. 5. During each excreta collection period, increased supplemental zinc concentrations significantly increased zinc excretion. However, the zinc source did not influence zinc utilisation. 6. As compared with zinc sulphate supplementation, the cumulative zinc excretion data indicate that adding zinc to the basal diet in the form of Availa Zn amino acid complex decreased zinc excretion.  相似文献   

Effect of epididymitis on semen quality of rams     

C V Bagley  W C Burrell  G M Esplin  J L Walters 《Journal of the American Veterinary Medical Association》1984,185(8):876-877

To better document the detrimental effect of ram epididymitis (RE) in large range flocks, a study was conducted to determine the correlation of palpable RE lesions and semen quality. Presence of leukocytes in the semen of rams affected with RE also was evaluated and found to correlate positively with RE lesions and inversely with semen quality. Rams with palpable RE lesions usually produced semen of reduced quality; however, some affected rams did produce good quality semen. The mean scrotal circumference varied significantly when rams were analyzed by breed, but not when grouped by RE status or classified by semen quality.  相似文献