In vitro infection of sheep lice (Bovicola ovis Schrank) by Steinernematid and Heterorhabditid nematodes.

Control of sheep lice with conventional pesticides can be compromised by difficulty in contacting lice in the dense water repellent fleeces of sheep, particularly when sheep have not been recently shorn. Entomopathogenic nematodes (ENs) are motile and are able to actively seek out insect hosts. They have particular advantages for the control of pests in cryptic habitats, such as the fleeces of sheep and avoid many of the problems frequently associated with chemical controls. This study investigated whether ENs were able infect and kill Bovicola ovis and compared the effectiveness of different species at different temperatures and when applied to wool. Four species of nematodes, Steinernema carpocapsae, Steinernema riobrave, Steinernema feltiae and Heterorhabditis bacteriophora were tested. All were shown to infect and kill lice in Petri dish assays at 30C. At 35C, the percent infection for S. carpocapsae and S. riobrave was significantly higher than for the other two species and percent infection by S. feltiae was significantly greater than for H. bacteriophora (P<0.05). At 37C the percent mortality induced by S. riobrave was significantly greater than for S. carpocapsae (P<0.05). All species were able to locate and infect lice in wool when formulated in water with 8% Tween 80. In wool assays the percent lice infected with nematodes was significantly greater for S. riobrave than H.bacteriophora at 25C, but there were no other differences between species (P=0.05). S. carpocapsae, S. riobrave and S. feltiae caused significantly higher lice mortality than H. bacteriophora at both 25 and 35C in wool assays, but mortality induced by the three steinernematid species did not differ significantly (P>0.05). It is concluded that of the ENs studied S. riobrave is likely to be most effective against B. ovis when applied to live sheep because of its greater tolerance to high temperatures and 'cruiser' foraging strategy .

Reduced risk of acute poisoning in Australian cattle from used motor oils after introduction of lead-free petrol.

Lead (Pb) poisoning of cattle has been relatively common in Australia and sump oil has been identified as an important cause of Pb toxicity for cattle because they seem to have a tendency to drink it. Lead-free petrol has been available in Australia since 1975, so the aim of this study was to assess the current risk to cattle from drinking used automotive oils. Sump or gear box oil was collected from 56 vehicles being serviced. The low levels of Pb found suggest that the removal of leaded petrol from the Australian market as a public health measure has benefited cattle by eliminating the risk of acute poisoning from used engine oil.

Controlling fly strike and louse infections in sheep with tea tree oil

This study aimed to assess the effect of tea tree oil based formulations against two major ectoparasitic diseases in the sheep industry, flystrike and louse infestation, and to provide data to assist the assessment of the commercial feasibility of development of tea tree oil based ectoparasiticides. The results demonstrate insecticidal effects against both sheep lice and blowflies and repellent effects against adult flies and maggots. Dipping sheep in a Tea Tree Oil based formulation appeared to completely eradicate lice and suggests its potential use in sheep dipping formulations. Repellent and insecticidal effects against sheep blowflies, together with previously reported anti-microbial and wound healing properties, suggest significant benefits from the inclusion of tea tree oil in flystrike and wound treatment formulations. These effects occurred at concentrations of Tea Tree Oil that suggest the commercial viability of development of Tea Tree Oil based formulations for sheep parasite control and wound treatment and a potential new market for Tea Tree Oil.

Female cattle welfare

Comparison of flank and Willis spaying on welfare of cows and heifers.

Antibiotic Sensitivity Testing

Respiratory bacterial pathogens in pigs are currently treated with antibiotics. Intervet - Schering Plough markets an antibiotic called Nurflor (Florfenicol) targeting respiratory pathogens. This project tests the effectiveness of this antibiotic against a series of respiratory pathogens. 6 isolates will be tested per serovar/strain and the isolates will be from 4 different farms using MIC testing. The sensitivity of Florfenicol will be compared to sensitivity of the organisms to Tilmicosin and Amoxicillin. Development of resistance to certain antibiotics have been reported, so it is important to have alternative antibiotics available to treat the respiratory pathogens on farms.

Haemophilus parasuis treatment

The aim of the project is to prove that live vaccination on the farm will protect the piglets from heterologous challenge with H. parasuis. The steps to achieve the aim of the project are to find a dose rate on the farm which guarantees colonisation of the vaccine strain and is safe On farm vaccinated and unvaccinated pigs are then shifted to CAAS at three weeks of age and challenged with a heterologous strains. The method is then applied on a large piggery for a period of nearly 12 months. We will also develop a freeze drying method and a technical manual of procedures to identify serovars prevailing on pig farms and which serovar to include into the vaccine.

Rapid typing of P multocida

Fowl cholera, caused by P. multocida, is a serious disease of poultry with sudden surges in mortality and an emerging disease of the free ranged poultry industries. This project will develop a more rapid and cost effective screening method for P. multocida. The impacts of this new method are manifold: It will lead to an improved understanding of the epidemiology of fowl cholera and the possible sources of entry onto the farm leading to improved biosecurity measures and control programs. Another impact is improved serotyping, which will ensure more effective and targeted vaccination programs. Improving prevention and control programs and decreasing the reliance on antibiotics will enhance the sustainability and profitability of the industry.

Rapid multiplex PCR assay for differentiating Pasteurella multocida serovars

To test the robustness and validity of our prototype LPS-specific multiplex PCR on P. multocida field isolates and develop the PCR into a diagnostic test capable of accurately and reliably typing P. multocida strains.

Fungal Biopesticide for cattle tick and buffalo fly control

Cattle ticks and buffalo flies impose significant economic burdens on the Northern Australian cattle and dairy industries. With the increased temperatures expected under climate change the range of parasites such as these is likely to extend. Current control options for these ectoparasites are limited by problems associated with chemical resistance and residues. Fungal biopesticides offer a sustainable and promising alternative method of control. Laboratory and animal studies have established the potential for the fungus Metarhizium in tick control and provided data that suggests a secondary effect of buffalo fly control is possible. Small field trials are required to obtain a proof of concept for the control of ticks and buffalo flies on animals.

Controlled exposure as a management tool for Glassers disease

Control of bacterial disease of pigs.

Unusual growth variants of Avibacterium paragallinarum.

Two isolates of haemophilic bacteria originally isolated in the 1980s from chickens were re-examined. The addition of a 10% sterile filtrate from an overnight culture of Staphylococcus epidermidis allowed growth of both isolates in solid and liquid media that were otherwise not capable of supporting the growth of these isolates. Using the modified media, genotypic and serotypic studies were performed, which confirmed both isolates to be Avibacterium paragallinarum, with one isolate being serovar A and the other serovar C. The unusual growth requirements of these two isolates reinforces the need for careful interpretation by diagnostic laboratories examining chickens showing signs of upper respiratory tract disease.

Positive results in a real-time PCR for type A influenza associated with the use of an inactivated vaccine.

A real-time reverse transcription polymerase chain reaction (qRT-PCR) test for the matrix gene of type A influenza viruses was used during the 2007 Australian equine influenza (EI) outbreak in order to confirm diagnosis and, later, eradication of the virus. During the EI outbreak, horses being exported required vaccination and individual proof of freedom from EI. At the end of the outbreak, positive results were obtained from four horses destined for export, because of contamination of the samples with the vaccine. This report highlights the need for EI testing and vaccination to occur on separate days and with the collection of swabs for testing to precede vaccination.

The first five days: field and laboratory investigations during the early stages of the equine influenza outbreak in Australia, 2007.

Until August 2007, Australia was one of only three countries internationally recognised to be free of equine influenza (EI). This report documents the diagnosis of the first cases of EI in Australian horses and summarises the investigations that took place over the next 5 days. During that time, a multifocal outbreak was identified across eastern New South Wales and south-eastern Queensland. The use of an influenza type A pan-reactive real-time reverse transcription polymerase chain reaction allowed rapid confirmation of suspect cases of EI.

The August 2007 equine influenza response management framework.

This section outlines the most important issues addressed in the management of the response in the two infected states, New South Wales and Queensland. There were differences in the management of the response between the states for logistic, geographic and organisation structural reasons. Issues included the use of control centres, information centres, the problems associated with the lack of trained staff to undertake all the roles, legislative issues, controls of horse movements, the availability of resources for adequate surveillance, the challenges of communication between disparate groups and tracing the movements of both humans and horses.

High-level coordination and strategy in the 2007 equine influenza outbreak response.

The equine influenza (EI) outbreak presented many challenges that required high-level coordination and decision making, as well as the development of new approaches for satisfactory and consistent resolution. This paper outlines the elements of the national coordination arrangements, preparatory arrangements in place prior to the outbreak that facilitated national coordination, and some of the issues faced and resolved in the response.