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A case control study was carried out within a cross-sectional survey designed to investigate the management by Queensland dairy farmers of the cattle tick Boophilus microplus. Although 199 farmers were surveyed, data on acaricide resistance were only obtained from 66 farms. Multiple models were used to predict the probability of acaricide resistance(More)
Published reports on the effect of buffalo fly Haematobia irritans exigua De Meijere (Diptera: Muscidae) and the closely related horn fly (H. irritans) were examined and analysed using non-linear weighted regression techniques in an attempt to establish the relationship between daily production loss (D), average number of parasites (n) and the average(More)
Myofibroblasts are unusual cells that share morphological and functional features of muscle and nonmuscle cells. Such cells are thought to control liver blood flow and kidney glomerular filtration rate by having unique contractile properties. To determine how these cells achieve their contractile properties and their resemblance to muscle cells, we have(More)
Forty mid-lactation Holstein-Friesian cows, 100% lot fed, were assigned to four groups for 15 weeks. Two groups of 10 cows were infested each week with a gradually increasing number of Boophilus microplus larvae, while the other two groups were maintained free of ticks. Milk yield and composition (including somatic cell count, SCC), liveweight, dry matter(More)
Bos taurus indicus cattle are less susceptible to infestation with Rhipicephalus (Boophilus) microplus than Bos taurus taurus cattle but the immunological basis of this difference is not understood. We compared the dynamics of leukocyte infiltrations (T cell subsets, B cells, major histocompatibility complex (MHC) class II-expressing cells, granulocytes) in(More)
This study determined the relationship between two measures of field fertility of 11 high-use Australian artificial insemination (AI) dairy bulls and thirty standard laboratory assessments of spermatozoal post-thaw viability. The two measures of field fertility used, conception rates (cCR) and non-return rates (cNRR), were both corrected for all major(More)
Environmental heat can reduce conception rates (the proportion of services that result in pregnancy) in lactating dairy cows. The study objectives were to identify periods of exposure relative to the service date in which environmental heat is most closely associated with conception rates, and to assess whether the total time cows are exposed to high(More)
Should the screwworm fly invade Australia, the sterile insect technique (as used successfully overseas) is currently the only feasible method of eradication. Used in conjunction with chemical control methods, it relies on large numbers of factory-reared, sterilized males competing successfully with wild males for the wild females. However, laboratory and(More)
The spatial population dynamics of an Old World screwworm fly, Chrysomya bezziana Villeneuve (OWS), outbreak in Australia have been modelled in two ways. The first model uses weekly growth indices derived from climatic data to predict the adult female population. The second is a detailed cohort life-cycle model. Due to technical and time constraints, the(More)
OBJECTIVE To investigate the extent of heat load problems, caused by the combination of excessive temperature and humidity, in Holstein-Friesian cows in Australia. Also, to outline how milk production losses and consequent costs from this can be estimated and minimised. PROCEDURES Long-term meteorological data for Australia were analysed to determine the(More)