Effect of breed of cattle on transmission rate and innate resistance to infection with Babesia bovis and B bigemina transmitted by Boophilus microplus     

RE BOCK  TG KINGSTON  AJ de  VOS 《Australian veterinary journal》1999,77(7):461-464

OBJECTIVE: To assess the effect of breed of cattle on the transmission rates of and innate resistance to Babesia bovis and B bigemina parasites transmitted by Boophilus microplus ticks. DESIGN: Groups of 56 purebred B indicus and 52 B indicus cross B taurus (50%, F1 generation) steers were placed in a paddock seeded with and also naturally infested with B microplus which were the progeny of females ticks fed on B taurus cattle specifically infected with a virulent isolate of B bovis. The cattle were placed in the infested paddock 50 days after seeding had started. PROCEDURE: Cattle were inspected from horseback daily for 50 days. Clinically ill cattle were brought to yards and assessed by monitoring fever, depression of packed-cell volume, parasitaemia and severity of clinical signs. Any animals that met preset criteria were treated for babesiosis. Blood samples were collected from all cattle on day 28, 35 and 42 after exposure and antibodies to Babesia spp and packed cell volume measured. RESULTS: All steers, except for one crossbred, seroconverted to B bovis and B bigemina by day 35 and 75% of the crossbred steers showed a maximum depression in packed cell volume of more than 15% due to infection with Babesia spp compared with only 36% of the B indicus group. Ten of the 52 crossbreds and 1 of the 56 B indicus steers showed severe clinical signs. Two of the crossbreds required treatment of which one died 2 weeks after initial treatment. CONCLUSIONS: Pure-bred B indicus cattle have a high degree of resistance to babesiosis, but crossbred cattle are sufficiently susceptible to warrant the use of preventive measures such as vaccination. Transmission rates of B bovis and B bigemina to B indicus and crossbred cattle previously unexposed to B microplus were the same.  相似文献   

Nesting activity of the loggerhead turtle caretta caretta in South Carolina,II. protection of nests from raccoon predation by transplantation     

S.E. Stancyk  O.R. Talbert  J.M. Dean 《Biological conservation》1980,18(4):289-298

Small mammals are significant predators of unhatched marine turtle nests in many parts of the world. Raccoons Procyon lotor destroy over 95% of the loggerhead turtle nests laid on some South Carolina beaches. To remove developing eggs from nest-associated clues which could aid raccoons, we transplanted whole and partially preyed-upon nests on Kiawah or Cedar Islands in 1972, 1973, 1977 and 1978. Eggs were moved to man-made cavities near the original nest cavities in erosion-free areas. Care was taken not to transfer clues from the original nest. Predation on wild (control) nests ranged from 55·1% (Cedar, 1978) to 93·8% (Kiawah, 1972). Transplant predation was significantly lower in all cases, ranging from 6·1% (Kiawah, 1972) to 18·7% (Kiawah, 1973). Hatching success of transplant was not significantly different from that of hatchery-reared or control clutches (60–81%). Transplanting may be an easier, less expensive method for protection of nests from predation or erosion than other procedures such as predator control, chemical aversion conditioning, or hatcheries, and merits further testing at other turtle rookeries.  相似文献   

Magnetic Collapse in Transition Metal Oxides at High Pressure: Implications for the Earth     

RE Cohen  II Mazin  DG Isaak 《Science (New York, N.Y.)》1997,275(5300):654-657

Magnetic collapse in transition metal ions is predicted from first-principles computations at pressures reached in the Earth's lower mantle and core. Magnetic collapse would lead to marked changes in geophysically important properties, such as elasticity and conductivity, and also to different geochemical behavior, such as element partitioning, than estimated by extrapolating low-pressure data, and thus change the understanding of Earth's structure and evolution. Magnetic collapse results from band widening rather than from changes in crystal field splitting under pressure. Seismic anomalies in the outer core and the lowermost mantle may be due to magnetic collapse of ferrous iron, dissolved in iron liquid in the outer core, and in solution in magnesiowustite in the lowermost mantle.  相似文献   

Rib osteomyelitis in three foals     

KM Neil  RE Charman  JR Vasey 《Australian veterinary journal》2010,88(3):96-100

Three foals aged between 21 and 44 days were presented for evaluation of pyrexia and lameness. Each had subcutaneous abscessation associated with osteomyelitis of a rib at the costochondral junction and pathological fracture of the affected rib; one foal had more than one rib affected. Other localised sites of infection included other sites of osteomyelitis, omphalophlebitis, uveitis, enterocolitis, and calcaneal bursitis. The subcutaneous abscessation and rib osteomyelitis was treated surgically in two foals. Salmonella typhimurium was isolated from the subcutaneous abscess in one foal and from the faeces of another. Two of the three foals were euthanased. Ultrasonography was a more useful modality than radiography for establishing the diagnosis of costal osteomyelitis.  相似文献   

林业病虫害防治工作中的问题及对策   总被引：2，自引：0，他引：2  

苏玉珍  热希 《内蒙古林业调查设计》2007,30(6):71-72,6

林业有害生物防治是国家减灾工程的重要组成部分,通过对乌拉特前旗林业有害生物防治工作存在问题的分析,提出了解决这类问题切实可行的对策措施。  相似文献   

Laryngeal paralysis in a Rottweiler with neuroaxonal dystrophy     

PF BENNNETT  RE CLARKE 《Australian veterinary journal》1997,75(11):784-786

  相似文献   

Alternative and Complementary Veterinary Medicine: A Holistic View of Functional Medicine.     

RE Clarke 《Australian veterinary journal》2001,79(11):777-777

  相似文献   

Cutaneous lymphosarcoma in a sugar glider     

I. HOUGH  RE REUTER  RS RAHALEY  C. BELFORD  R. MILLER  G. MITCHELL 《Australian veterinary journal》1992,69(4):93-94

  相似文献   

Simulated increase of hurricane intensities in a CO2-warmed climate     

TR Knutson  RE Tuleya  Y Kurihara 《Science (New York, N.Y.)》1998,279(5353):1018-1020

Hurricanes can inflict catastrophic property damage and loss of human life. Thus, it is important to determine how the character of these powerful storms could change in response to greenhouse gas-induced global warming. The impact of climate warming on hurricane intensities was investigated with a regional, high-resolution, hurricane prediction model. In a case study, 51 western Pacific storm cases under present-day climate conditions were compared with 51 storm cases under high-CO2 conditions. More idealized experiments were also performed. The large-scale initial conditions were derived from a global climate model. For a sea surface temperature warming of about 2.2 degrees C, the simulations yielded hurricanes that were more intense by 3 to 7 meters per second (5 to 12 percent) for wind speed and 7 to 20 millibars for central surface pressure.  相似文献   

False hyperchloraemia in a dog secondary to ingestion of horse feed supplemented with potassium bromide     

RE Peacock  L Smart 《Australian veterinary journal》2013,91(8):320-322

  相似文献