The comparative pathogenicity of four serovars of Actinobacillus (Haemophilus) pleuropneumoniae   总被引：1，自引：0，他引：1  

RJ ROGERS  LE EAVES  PJ BLACKALL  KF TRUMAN 《Australian veterinary journal》1990,67(1):9-12

The pathogenicity of 2 isolates of each of serovars 7, 3, 1 and 2 of Actinobacillus pleuropneumoniae was tested by intranasal inoculation into 60, 6-week-old large white pigs. Four dose rates varying from 0.27 to 560 x 10(6) organisms per pig with 10-fold serial dilutions were used. Surviving pigs were necropsied 7 days after inoculation. The proportion of pigs dying and developing gross lesions following infection was significantly greater for pigs given serotype 1 than for each of the other 3 serotypes, which did not differ significantly from each other. Twelve of 16 pigs given either of the 2 isolates of serovar 1 died after acute illness and 1 of 44 pigs given either of the 2 isolates each of serovars 7, 3 and 2 died. Pigs given serovar 1 showed high temperatures, severe respiratory distress, frothy haemorrhagic nasal discharge and weight loss. Lung lesions were produced in all 16 pigs given serovar 1, in 7 of 14 pigs given serovar 7, 7 of 14 pigs receiving serovar 3 and in 5 of 16 pigs given serovar 2. The lethal infections were characterised by a severe acute fibrinohaemorrhagic necrotising pleuropneumonia, whereas non-lethal cases had lung lesions ranging from necrotising purulent pleuropneumonia to abscessation. Significant differences between isolates in proportions of tissues culture positive for A. pleuropneumoniae for serovars 7 and 2, but not for serovars 3 and 1 suggested that isolates may vary in virulence within serovars, but more detailed studies are needed to clarify this point.  相似文献   

Rings versus knife for docking and castration of lambs     

DJ MELLOR  RJ HOLMES † 《Australian veterinary journal》1988,65(12):403-404

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Experimental evidence that tryptamine alkaloids do not cause Phalaris aquatica sudden death syndrome in sheep     

CA BOURKE  MJ CARRIGAN  RJ DIXON† 《Australian veterinary journal》1988,65(7):218-220

The acute toxicity for sheep of 3 alkaloids that occur in Phalaris acquatica was examined by intravenous and oral administration. The lowest tested dose rates that produced clinically observed signs were, for 5-methoxy dimethyltryptamine, 0.1 mg/kg body weight intravenously and 40 mg/kg orally; for gramine, 10 mg/kg intravenously and 500 mg/kg orally; and for hordenine, 20 mg/kg intravenously and 800 mg/kg orally. All induced the clinical signs observed in the nervous form of phalaris toxicity, but none induced the cardiac, sudden death, syndrome.  相似文献   

Severity and persistence of footrot in Merino sheep experimentally infected with a protease thermostable strain of Dichelobacter nodosus at five sites     

LJ DEPIAZZI  WD ROBERTS  CD HAWKINS  MA PALMER  DR PITMAN  NC MCQUADE  PD JELINEK  DJ DEVEREAUX  RJ RIPPON 《Australian veterinary journal》1998,76(1):32-38

Objective To test the hypothesis that ovine footrot associated with a thermostable protease strain of Dichelobacter nodosus undergoes self cure or is sustained as an annually recurring disease, depending on the environment.
Design and procedure Forty Merino sheep from a single blood line were infected with a protease thermostable strain of D nodosus a t each of five sites in Western Australia. Footrot lesions and microscopic evidence of D nodosus were recorded every fortnight for 2.5 years, supplemented by laboratory culture. Rainfall, soil and air temperature, pasture quantity and composition and soil types were also recorded. Flocks that apparently self cured were relocated to a more favourable site for footrot in the final spring season.
Results The maximum prevalence of feet with clinical footrot lesions was 80.6, 1.3, 14.4, 3.8 and 88.1% at the five sites. Severe footrot occurred for three consecutive spring seasons at one site that had clay loam soil and at least 3500 kg/ha total pasture dry matter annually. However, the infection was asymptomatic for up to 10 weeks between outbreaks. D nodosus was isolated from flocks for 2.5 years at only two sites, although there was microscopic evidence of the organism at other sites in the final year. A thermolabile variant (strain U6) of D nodosus was isolated from the two sites where footrot persisted.
Conclusion Depending on time and location, ovine footrot induced by a protease thermostable strain of D nodosus either self cured or persisted as annual outbreaks interspersed with periods of asymptomatic infection.  相似文献   

The Importance of Interactions Among Nutrition, Seasonality and Socio-sexual Factors in the Development of Hormone-free Methods for Controlling Fertility     

RJ Scaramuzzi  GB Martin 《Reproduction in domestic animals》2008,43(S2):129-136

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Ecological traits of fish assemblages from Mediterranean Europe and their responses to human disturbance   总被引：2，自引：1，他引：1  

T. FERREIRA  & J. OLIVEIRA  N. CAIOLA  & A. DE SOSTOA  F. CASALS  R. CORTES  A. ECONOMOU  & S. ZOGARIS  D. GARCIA-JALON  M. ILHÉU  F. MARTINEZ-CAPEL  D. PONT  & C. ROGERS  J. PRENDA 《Fisheries Management and Ecology》2007,14(6):473-481

Abstract  Mediterranean river systems are characterised by more diverse fish assemblages and regional ecological processes compared with the rest of Europe. A data set from Mediterranean France, Iberia and Greece (∼2000 sites) was used to describe the characteristics of fish assemblages, explore their responses to anthropogenic disturbance and analyse the implications for river quality assessment. There was a southwards decline in species richness per site, but endemicity and proportion of alien species increased. Sites in the eastern Mediterranean had higher endemicity, lower site richness and lower number of alien species than sites in western Mediterranean Europe. Assemblage composition differed between Mediterranean sub-regions, but was dominated by three major fish types: a salmonid fish type common throughout the study area and two cyprinid-dominated fish types (in some sub-regions, Salmo trutta L. is present but not numerically dominant), corresponding to a gradient in hydrological and temperature regimes. Metric responses to perturbation were compared with those found at the European (larger scale) and basin (smaller scale) levels. Overall metric response was weaker in this Mediterranean application. The best responses to human pressure were usually obtained with abundance-based metrics and included the contribution of naturalised alien species. Some widespread alien species contributed to the response to anthropogenic alteration (notably Cyprinus carpio L. and Lepomis gibbosus (L.)).  相似文献   

Fertilisation and weed control effects on yield and weeds in durum wheat grown under rain-fed conditions in a Mediterranean climate     

A GARCÍA-MARTÍN  RJ LÓPEZ-BELLIDO†  & JM COLETO 《Weed Research》2007,47(2):140-148

Summary A field study was undertaken to examine the effect of fertiliser type and weed control system on grain yield, yield components and weed population in durum wheat ( Triticum turgidum. var. durum) grown in a 4-year rotation [bare fallow–barley ( Hordeum vulgare )–vetch ( Vicia sativa )–wheat]. Fertilisation treatments were: no fertilisation, organic fertilisation with 2500 kg ha⁻¹ of compost (sheep manure and cereal straw) and chemical fertilisation with 100–60–60 kg ha⁻¹ of NPK. Weed-control treatments were: no control, herbicide, harrowing with long-flex spring tines and strip sowing with inter-row hoeing. Chemical fertilisation increased grain yield with respect to the other treatments, amongst which no significant differences were noted. Weed-control systems afforded no improvement in yield compared with controls; indeed, yields obtained using inter-row hoeing were lower. The weed population consisted of a large variety of species, of which the most important were Convolvulus arvensis and Polygonum aviculare . Application of weed-control systems reduced weed density. Herbicide was the most effective, reducing weed biomass by 80%, whilst harrowing and hoeing reduced weed biomass by 40% and 52% respectively. Inter-row hoeing does not appear to be a viable alternative to herbicides, when used as the sole weed control method in a non-diverse cropping system in Mediterranean climates. The lack of response to compost suggests a need for further long-term research.  相似文献   

AN OS CLITORIDIS IN A BITCH     

R. J. ROGERS 《Australian veterinary journal》1971,47(8):369-369

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INTRA-UTERINE INFECTION OF A PIG BY PSEUDOMONAS PSEUDOMALLEI     

R. J. ROGERS  M.V.Sc.  D. J. ANDERSEN  B.Sc. 《Australian veterinary journal》1970,46(6):292-292

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Assessment of the potential toxicity of a poison for rabbits, pindone (2-pivalyl 1, 3 indandione), to domestic animals     

GR MARTIN  RJ SUTHERLAND†  ID ROBERTSON†  WE KIRKPATRICK  DR KING  PJ HOOD† 《Australian veterinary journal》1991,68(7):241-243

The toxicity of pindone, a rabbit poison, to horses, cattle, goats, chickens, dogs and cats was investigated, using extension of prothrombin time (PT) as an index of poisoning. The daily dose of pindone, administered for 5 days, ranged from 0.3 mg/kg for dogs to 2.5 mg/kg for chickens. This range of dose rates was considered to be indicative of the worst possible case that could arise following a campaign of baiting for rabbits. Although significant elevations in PT (more than double baseline values) were noted in all species other than horses, clinical signs of anticoagulant poisoning were not observed in any of the species tested. From the observed PT, cattle and cats appeared to be the most susceptible, and horses the least susceptible, to pindone toxicity. The half-lives of the elevated PT were calculated as 3.1 days for cattle, 2.8 days for goats and chickens, 1.9 days for horses and dogs and less than one day for cats. It is proposed that these half-lives can be used as a guide for determining the duration of treatment of pindone-affected animals.  相似文献