Productivity and health effects of anaplasmosis and babesiosis on Bos indicus cattle and their crosses, and the effects of differing intensity of tick control in Australia

Tick fever is an important disease of cattle where Rhipicephalus (Boophilus) microplus acts as a vector for the three causal organisms Babesia bovis, Babesia bigemina and Anaplasma marginale. Bos indicus cattle and their crosses are more resistant to the clinical effects of infection with B. bovis and B. bigemina than are Bos taurus cattle. Resistance is not complete, however, and herds of B. indicus-cross cattle are still at risk of babesiosis in environments where exposure to B. bovis is light in most years but occasionally high. The susceptibility of B. indicus cattle and their crosses to infection with A. marginale is similar to that of B. taurus cattle. In herds of B. indicus cattle and their crosses the infection rate of Babesia spp. and A. marginale is lowered because fewer ticks are likely to attach per day due to reduced numbers of ticks in the field (long-term effect on population, arising from high host resistance) and because a smaller proportion of ticks that do develop to feed on infected cattle will in turn be infected (due to lower parasitaemia). As a consequence, herds of B. indicus cattle are less likely than herds of B. taurus cattle to have high levels of population immunity to babesiosis or anaplasmosis. The effects of acaricide application on the probability of clinical disease due to anaplasmosis and babesiosis are unpredictable and dependent on the prevalence of infection in ticks and in cattle at the time of application. Attempting to manipulate population immunity through the toleration of specific threshold numbers of ticks with the aim of controlling tick fever is not reliable and the justification for acaricide application should be for the control of ticks rather than for tick fever. Vaccination of B. indicus cattle and their crosses is advisable in all areas where ticks exist, although vaccination against B. bigemina is probably not essential in pure B. indicus animals.

Forest health guide: symptoms of insect and fungal damage on trees

The Forest health guide: symptoms of insect and fungal damage on trees is intended to help forestry and quarantine staff undertake tree health assessments, in both forest and urban environments. The guide is designed to be used as a quick reference to common symptoms of damage, not as an identification guide to particular insect pests and pathogens.

Vegetable soil health systems for overcoming limitations causing soil borne diseases

The purpose of the report is to summarise progress in developing vegetable production systems with improved soil health that overcome soil limitations with the potential to suppress soil borne diseases. Management approaches to soil health improvement were regionally specific to overcome regional soil limitations in different production environments.

Fate of key food-borne pathogens associated with intensive pig and poultry farming environments

Intensive pig and poultry farming in Australia can be a source of pathogens with implications for food-safety and/or human illness. Seven studies were undertaken with the following objectives: · Assess the types of zoonotic pathogens in waste · Assess the transfer of pathogens during re-use both within the shed and externally in the environment · The potential for movement of pathogens via aerosols In the first and second studies the extent of zoonotic pathogens was evaluated in both piggery effluent and chicken litter and Salmonella and Campylobacter were detected in both wastes. In the third study the dynamics of Salmonella during litter re-use was examined and results showed a trend for lower Salmonella levels and serovar diversity in re-used litter compared to new litter. Thus, re-use within the poultry farming system posed no increased risk. The fourth study addressed the direct risks of pathogens to farm workers due to reuse of piggery effluent within the pig shed. Based on air-borne Escherichia coli (E. coli) levels, re-using effluent did not pose a risk. In the fifth study high levels of Arcobacter spp. were detected in effluent ponds and freshly irrigated soils with potential food-safety risks during the irrigation of food-crops and pasture. The sixth and seventh studies addressed the risks from aerosols from mechanically ventilated sheds. Staphylococci were shown to have potential as markers, with airborne levels gradually dropping and reaching background levels at 400 m distance. Salmonella was detected (at low levels) both inside and outside the shed (at 10 m). Campylobacter was detected only once inside the shed during the 3-year period (at low levels). Results showed there was minimal risk to humans living adjacent to poultry farms This is the first comprehensive analysis studying key food-safety pathogens and potential public health risks associated with intensively farmed pigs and poultry in Australia.