A longitudinal study of the effect of Theileria orientalis Ikeda type infection on three New Zealand dairy farms naturally infected at pasture

Publication date: Available online 12 November 2019Source: Veterinary ParasitologyAuthor(s): KE Lawrence, K. Gedye, WE PomroyAbstractThe aims of this study were to monitor the change in Theileria orientalis Ikeda type infection intensity, haematocrit, milk production and reproduction on three New Zealand spring calving dairy herds, over the 2014 to 2015 milking season.Three spring calving dairy farms, A, B and C, from high risk (endemically stable), low risk (endemically unstable), and zero risk (disease-free) tick areas respectively were followed through the 2014 to 2015 milking season. On Farms, A and B, 100 cows were randomly selected at the first visit, and the same cows blood sampled every month thereafter, whilst on Farm C, the whole herd was blood sampled bimonthly (140 cows). Blood samples were tested for haematocrit, by centrifugation, and Ikeda infection intensity, using qPCR. Animals that were Ikeda type PCR positive at the first sampling were described as prevalence cases and cows that were negative at the first sampling and became PCR positive during the sampling period were described as incidence cases. Production and reproduction data were accessed through LIC MINDA® and milk production data was standardised to energy corrected milk (ECM). In addition, the effect of buparvaquone (BPQ) treatment on milk production was estimated on Farm B.The prevalence of infection at the first sampling was 100% on Farm A, 57% on Farm B and 26% on Farm C. The incidence risk of ...
Source: Veterinary Parasitology - Category: Veterinary Research Source Type: research