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71.
72.
The housing, management and internal parasite control practices used in piggeries in Western Australia was surveyed by interviewing the owner/manager of 100 randomly selected piggeries. At the time of the interview 20 faecal samples were collected from pigs and examined for evidence of internal parasites. Most herds (80%) in which anthelmintics were used, had evidence of nematode infection. Some pig producers were using an anthelmintic that was ineffective against nematode species present while some herds had nematodes that should have been controlled by the anthelmintic being used. Prevalence of nematode infection was higher in pigs run in paddocks than in pigs housed intensively. Washing sows prior to farrowing was associated with a lower prevalence of nematode infection. The findings suggested that pig producers should ensure that the anthelmintic used is effective against the nematodes present in their pigs. It was concluded that administering anthelmintics as a single dose in the feed may not be the most effective method of deworming pigs. 相似文献
73.
Agents of Psittacosis-Lymphogranuloma Venereum Group Isolated from Muskrats and Snowshoe Hares in Saskatchewan 总被引:2,自引:0,他引:2 下载免费PDF全文
J. Spalatin C. E. O. Fraser R. Connell R. P. Hanson D. T. Berman 《Canadian journal of veterinary research》1966,30(9):260-264
Agents lethal to chicken embryos and mice were isolated from the blood and spleen of 2 muskrats and 2 snowshoe hares which died during the cataclysmic die-off of 1961 in Central Saskatchewan. The 4 isolates are probably identical. One of them was identified as a member of the psittacosis-lymphogranuloma venereum (PLV) group of organisms on the basis of morphological and tinctorial properties and on the possession of group specific antigens. Application of the method of specificity differences permitted its serotype differentiation. 相似文献
74.
The presence of a phosphodiesterase activity in NDV is reported. This activity has a different pH optimum from the phosphodiesterase activity found in normal, uninfected cells, is inhibited by NDV antiserum, and is associated with the envelope polypeptides of the virus. 相似文献
75.
76.
Some behavioural aspects of milk ejection failure by sows 总被引:1,自引:0,他引:1
D Fraser 《The British veterinary journal》1977,133(2):126-133
77.
78.
Trends in the numbers of infective nematode larvae on pasture plots contaminated by cattle at different seasons of the year were defined in 3 different climatic regions. The main nematodes were Ostertagia ostertagi, Trichostrongylus spp, Haemonchus spp and Cooperia spp.
On the North Coast of New South Wales with a sub-tropical climate, the numbers of infective larvae of all 4 nematodes rose rapidly to peak levels soon after each seasonal period of contamination began, then fell quickly within a few months. On the Central Coast of New South Wales, the trends were similar to those on the North Coast, except that the larvae persisted on the pasture for a much longer time. On the Northern Tablelands of New South Wales, where temperatures were much colder than on the coast, larval development was slower and major peaks of larval availability did not occur until early spring. These different seasonal trends in each region were considered to be related to the climatic differences between the regions.
On pastures which were contaminated continuously, larval numbers reached maximum levels in mid-winter on the Central Coast and in early spring on the Northern Tablelands. It was concluded that the majority of these larvae were derived from the contamination of pastures in autumn and winter. Subsequently in summer, a rapid dying out of larvae was observed in all the regions, probably due to the effect of hotter weather.
The studies suggest that a reduction in the contamination of pasture with nematode eggs in autumn and winter could result in pastures carrying fewer larvae and thus form the basis of effective worm control programs for cattle. 相似文献
On the North Coast of New South Wales with a sub-tropical climate, the numbers of infective larvae of all 4 nematodes rose rapidly to peak levels soon after each seasonal period of contamination began, then fell quickly within a few months. On the Central Coast of New South Wales, the trends were similar to those on the North Coast, except that the larvae persisted on the pasture for a much longer time. On the Northern Tablelands of New South Wales, where temperatures were much colder than on the coast, larval development was slower and major peaks of larval availability did not occur until early spring. These different seasonal trends in each region were considered to be related to the climatic differences between the regions.
On pastures which were contaminated continuously, larval numbers reached maximum levels in mid-winter on the Central Coast and in early spring on the Northern Tablelands. It was concluded that the majority of these larvae were derived from the contamination of pastures in autumn and winter. Subsequently in summer, a rapid dying out of larvae was observed in all the regions, probably due to the effect of hotter weather.
The studies suggest that a reduction in the contamination of pasture with nematode eggs in autumn and winter could result in pastures carrying fewer larvae and thus form the basis of effective worm control programs for cattle. 相似文献
79.
Plasmid, protein and restriction endonuclease analysis (REA) profiles and multilocus enzyme electrophoresis were used to effect a molecular discrimination of twenty-seven Campylobacter coli serogroup 20, biotype 1 (Lior) strains. These strains were not outbreak-associated but were isolated from a number of different countries and different animal and environmental sources. Each of the techniques was able to discriminate, to various degrees, between the serogroup 20, biotype 1 strains. The choice of a particular technique depends to a large extent on the level of discrimination desired, the previous experiences of the investigator and on the laboratory facilities at hand. REA profiles demonstrated the greatest degree of discrimination between these strains. Plasmid and protein profiles could discriminate reasonably well. Multilocus enzyme electrophoresis (allozyme typing) and protein profiles may prove effective in subgrouping serogroup 20, biotype 1 strains. 相似文献
80.
Phylogenetic characterisation of bluetongue viruses from naturally-infected insects, cattle and sheep in Australia 总被引:1,自引:0,他引:1
KA McCOLL AR GOULD LI PRITCHARD L MEL VILLE† G. BELLIS† 《Australian veterinary journal》1994,71(4):102-105
SUMMARY The polymerase chain reaction was used to detect the presence of blue-tongue virus (BTV) in a number of clinical and insect samples collected in the Northern Territory of Australia. Sequence analyses of the amplified BTV genes differentiated endemic Australian and exotic viruses. Two potential exotic BTV were detected as a result of PCR analyses of blood from sentinel animals and of the insect vector, Culicoides wadai. The detection of BTV in C wadai was the first direct demonstration of the presence of BTV in this potential vector. This new technology can significantly reduce the time taken for a diagnosis from a clinical sample and increase the amount of useful information obtained on a BTV isolate by using rapid sequencing techniques. Sequence data were used to differentiate between BTV20 isolated in 1975 and two isolates of the same serotype, isolated in 1992, and indicated that the latter were probably a recent incursion into Australia from Indonesia due to their greater VP3 sequence homology to the BTV9 (Java) than to Australian BTV isolates. 相似文献