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排序方式: 共有1067条查询结果,搜索用时 15 毫秒
1.
G W De Lisle D M Collins H F Huchzermeyer 《The Onderstepoort journal of veterinary research》1992,59(2):163-165
Restriction endonuclease analysis and DNA hybridization revealed five ovine strains of Mycobacterium paratuberculosis from South Africa had identical DNA patterns to an ovine strain from Canada. Genetically this strain type has features in common with the two major groups of M. paratuberculosis. 相似文献
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Transmission of porcine reproductive and respiratory syndrome virus from persistently infected sows to contact controls. 总被引:3,自引:0,他引:3
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M D Bierk S A Dee K D Rossow S Otake J E Collins T W Molitor 《Canadian journal of veterinary research》2001,65(4):261-266
The objective of this study was to determine if porcine reproductive and respiratory syndrome virus (PRRSV) could persist in non-pregnant sows and if persistently infected sows could transmit virus to naive contact controls. Twelve PRRSV-naive, non-pregnant sows (index sows) were infected with a field isolate of PRRSV and housed in individual isolation rooms for 42 to 56 days postinfection. Following this period, 1 naive contact sow was placed in each room divided by a gate allowing nose-to-nose contact with a single index sow. Index sows were not viremic at the time of contact sow entry. Virus nucleic acid was detected by polymerase chain reaction, and infectious virus was detected by virus isolation in sera from 3 of the 12 contact sows at 49, 56, and 86 days postinfection. All 3 infected contacts developed PRRSV antibodies. Virus nucleic acid was detected in tissues of all of the 12 index sows at 72 or 86 days postinfection. Nucleic acid sequencing indicated that representative samples from index and infected contacts were homologous (> 99%) to the PRRSV used to infect index sows at the onset of the study. This study demonstrates that PRRSV can persist in sows and that persistently infected sows can transmit virus to naive contact animals. 相似文献
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The relationship between air quality--its dust content--and respiratory diseases of animals in the food industry and otherwise is examined. The correlation between dust content and incidence of disease in farm animals is also discussed. Lesions caused either directly or indirectly by dust-transported microorganisms are reviewed. Effects of dust on animal performance are included. This review is an attempt to compile available information on the natural occurrence of stable dust and the possibilities for its measurement and control. 相似文献
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N. LA PORTA P. CAPRETTI K. KAMMIOVIRTA R. KARJALAINEN & K. KORHONEN 《Plant pathology》1997,46(5):773-784
Eighty-six Heterobasidion annosum isolates, mainly belonging to the F intersterility group and obtained from 32 different geographical localities in Italy, were subjected to genetic analysis by the Random Amplified Polymorphic DNA (RAPD) markers. The similarity between F and S groups was higher than that between F and P. In UPGMA Cluster Analysis, the F isolates originating from the same locality usually grouped in the same cluster. The isolates also showed a tendency to group at the level of larger geographical areas. Within the F group, isolates from the south of the Italian peninsula showed the highest genetic variation and northern isolates from the Alpine regions showed the lowest. This indicates a gradual cline along the peninsula. The genetic variability in the Italian F group is discussed in relation to the past and present distribution of the host species in Italy and Europe. 相似文献
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Sheila M McGuirk Michael Collins 《Veterinary Clinics of North America: Food Animal Practice》2004,20(3):593-603
Provision of an adequate immunoglobulin mass to dairy calves is an essential component for survival, health, and future productivity. To prevent FPT of immunity due to suckling of the dam, newborn dairy calves should be removed from the calving area within 30 minutes of birth. First and later lactation cows are suitable colostrum donors, provided they are healthy, well-vaccinated, have had optimal transition management, and an appropriate dry-period length. Early colostrum collection yields an adequate immunoglobulin mass provided that 3 to 4 L of colostrum is fed to the newborn calf. Regular testing for the adequacy of the dairy's colostrum feeding program is an excellent way to prevent calf health problems and identify potential need for CSs or replacement products. 相似文献
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Laryngeal mask airway and transient hypercapnic hyperpnea for video‐endoscopic assessment of unilateral laryngeal paralysis in dogs
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