The West Coast region of the South Island of New Zealand is recognised as having a high prevalence of liver fluke infection, however, few studies have tested this assumption. This study aimed to estimate the seroprevalence and spatial distribution of liver fluke infection in most West Coast and some Canterbury dairy herds using bulk milk ELISA. Herds were bulk milk sampled on three occasions, twice, a week apart in March 2017 (n = 430 and n = 99) and once in October 2017 (n = 412). The concentration of liver fluke antibodies was estimated using the IDEXX Fasciolosis Verification ELISA (IDEXX Europe BV, Hoofdorp, The Netherlands) on these bulk milk samples. Herds were categorised according to the test instructions, with "medium" (>= 20 % cows infected) or "strong" (>= 50 % cows infected) results designated as production limiting. All herds were also sent a short questionnaire about awareness of liver fluke and treatment in their herds. The agreement between the IDEXX results for 99 herds sampled twice in March 2017, and between the IDEXX results for March and October for all herds was assessed with a Kappa test. There was a substantial agreement between the two March tests, kappa = 0.7 (95 % CI 0.58-0.82) and moderate agreement between the March and October samples kappa = 0.41 (95 % CI 0.34-0.48). The results of the questionnaire were linked to the IDEXX results, and the distribution of herds categorised by their IDEXX result plotted. At the March and October samplings 0/35 (0 %) and 0/27 (0 %) Canterbury herds, 248/395 (63 %) and 193/385 (50 %) of West Coast herds had a production limiting seroprevalence of liver fluke infection. Mapping showed that West Coast herds with a production limiting infection were clustered in coastal areas, whereas those without, were clustered in inland valleys. The odds of a coastal West Coast dairy herd having a production limiting seroprevalence of liver fluke were 10.7 (95 % CI, 6.6-17.3) times that of an inland herd in March and 8.6 (95 % CI, 5.4-13.8) times in October. There was no effect on IDEXX ELISA SP% (p = 0.92) of herds which were treated for liver fluke at dry off soon after the March test compared to their SP% in the following October test, soon after calving. The results show that liver fluke infection is a potentially serious problem for West Coast dairy herds especially for those on coastal river plains prone to flooding.

In many regions of New Zealand liver fluke is endemic, infecting most grazing ruminants, including cattle, sheep, and deer. Restricting the economic losses and welfare costs associated with liver fluke relies on accurately identifying those animals with a production limiting infection. This has proven a difficult goal and although several antemortem quantitative tests are available, including faecal egg counts (FEC), serum ELISA and coproantigen ELISA, none can be considered a gold standard test of liver fluke infection. The accepted gold standard test for fascioliasis is the total fluke count, which is both laborious and can only be completed at post-mortem. This study aimed to compare the performance of four liver fluke diagnostic tests, against the results of a gold standard total fluke count test. Two groups of cattle were selected, 29 culled mixed age beef cows (MAC) and ten 30-month-old steers. The cattle were blood sampled and faecal sampled prior to slaughter and their whole livers recovered post slaughter at the abattoir. Liveweight was also recorded at slaughter. After collection, each liver was weighed, scored for gross pathology, then serum, faeces and livers were frozen at -20 degrees C for later analysis. Faecal egg counts and F. hepatica copro-antigen ELISA tests were completed on the faecal samples and total fluke counts were completed on the livers. Fasciola hepatica antibody concentration in serum samples were quantified using a commercial ELISA test. Poisson regression models were built to model the association between each diagnostic test and the total fluke count, and a linear regression model was built to examine the relationship between each diagnostic test and live weight at slaughter. The median fluke count was significantly higher in MAC than steers (p = 0.01), and F. hepatica eggs were present in 100% steers and 66% MAC. There was a significant effect of copro-antigen ELISA value on total fluke count (p < 0.0001), with a coproantigen ELISA value = 20.1 predicting 10 flukes and a value = 44.8 predicting 30 flukes. There was also a significant effect of FEC on total fluke count (p = 0.002) but the R-squared value for this model was lower. There was no association between liver fibrosis score or antibody ELISA test and total fluke count (p = 0.95, p = 0.73, respectively). There was a significant effect of total fluke count (p = 0.03) on liveweight at slaughter, with liveweight falling 20.4 kg for each unit increase in loge (total fluke count). There was no effect of FEC (p = 0.11), antibody ELISA (p = 0.55) or copro-antigen ELISA value (p = 0.16) on liveweight at slaughter. Taken together, these results show that the coproantigen ELISA test is the better test for estimating the true liver fluke burden and that the number of flukes in the liver has a negative effect on cattle live weights at slaughter.

Flystrike remains an important animal health issue on New Zealand sheep farms. To date no useful predictive tool to assist farmers to develop control options has been available. The aim of this study was to use National Institute of Water and Atmospheric Research (NIWA) virtual climate station data in New Zealand to develop a weather-based model to accurately predict the presence of Lucilia spp. on sheep farms throughout New Zealand. Three LuciTrap (R) baited fly traps were positioned on each of eight sheep farms throughout New Zealand (5 in the North Island and 3 in the South Island). The traps were put out for both the 2018 - 2019 and 2019 - 2020 seasons. They were emptied each week and the flies morphologically identified; with the counts of Lucilia cuprina and L. sericata combined as Lucilia spp. The count data for Lucilia spp. for each week of trapping was transformed into a binary outcome and a generalised linear mixed effects models fitted to the data, with farm as a random effect. The dependent variable was Lucilia spp. flies caught, yes or no, and the independent variables were mean weekly climate variables from the nearest NIWA virtual climate station to that farm. The model was trained on the 2018 - 2019 catch data and tested on the 2019 - 2020 catch data. A cut point was identified which maximised the model ' s ability to correctly predict whether Lucilia spp. were present or not for the 2019 - 2020 catch data, and the sensitivity, specificity, accuracy, and area under the curve (AUC) of the model calculated. The final model included just 3 significant variables, mean weekly 10 cm soil temperature, mean weekly soil moisture index, and mean weekly wind speed at 10 m. Mean weekly 10 cm soil temperature accounted for 64.7% of the variance explained by the model, mean weekly soil moisture index 34.7% and mean weekly wind speed at 10 m only 0.6%. The results showed that the predictive model had a sensitivity of 0.93 (95% CI = 0.80 - 0.98) and a specificity of 0.75 (95% CI = 0.62 - 0.85), using a cut point for the probability of Lucilia spp. being present on farm = 0.383. This model provides New Zealand farmers with a tool which will allow them to know when Lucilia spp. flies will likely be present and thus more accurately plan their interventions to prevent flystrike.

Theileria orientalis (Ikeda) was first detected in New Zealand in 2012, becoming endemic in most of the North Island, and can cause incidences of anaemia and death. Research has been performed in New Zealand on the incidence and severity of infection. Through this research anecdotal evidence has been found to suggest a potential genetic susceptibility component in the response of the host to the parasite. To investigate the genetic susceptibility of cattle to T. orientalis (Ikeda), 99 calves born in 2016 as part of a separate experiment and grown in six grazing herds, were examined for their response to the parasite. In addition to measuring live weight, two blood collections were taken in the first four months of life which were used to measure packed cell volume by haematocrit and qPCR to assess parasite load. Heritability was calculated and was low for parasite load, but the result indicates that there is some potential to increase resistance through selective breeding. The mechanisms of the differences in parasite load were not elucidated in this research; however, significant variation was found among herds and sires, indicating that both genetic selection and environmental management could be utilised to reduce parasite load in growing calves.

Aims: To determine whether evidence for infection with Theileria orientalis (Ikeda) could be identified in samples of commercial red deer (Cervus elaphus), horses, and working farm dogs in New Zealand. Methods: Blood samples were collected during October and November 2019 from a convenience sample of red deer (n = 57) at slaughter. Equine blood samples (n = 50) were convenience-sampled from those submitted to a veterinary pathology laboratory for routine testing in January 2020. Blood samples, collected for a previous study from a convenience sample of Huntaway dogs (n = 115) from rural regions throughout the North and South Islands of New Zealand between August 2018 and December 2020, were also tested. DNA was extracted and quantitative PCR was used to detect the T. orientalis Ikeda major piroplasm surface protein (MPSP) gene. A standard curve of five serial 10-fold dilutions of a plasmid carrying a fragment of the T. orientalis MPSP gene was used to quantify the number of T. orientalis organisms in the samples. MPSP amplicons obtained by end-point PCR on positive samples were isolated and subjected to DNA sequencing. The resulting sequences were compared to previously published T. orientalis sequences. Results: There were 6/57 (10%) samples positive for T. orientalis Ikeda from the deer and no samples positive for T. orientalis Ikeda from the working dogs or horses. The mean infection intensity for the six PCR-positive deer was 5.1 (min 2.2, max 12.4) T. orientalis Ikeda organisms/mu L. Conclusions and clinical relevance: Red deer can potentially sustain low infection intensities of T. orientalis Ikeda and could act as reservoirs of infected ticks. Further studies are needed to determine whether na & iuml;ve ticks feeding on infected red deer can themselves become infected. Abbreviations: Cq: Quantification cycle; LOQ: Limits of quantification; MPSP: Major piroplasm surface protein; qPCR: Quantitative polymerase chain reaction

The liver fluke Fasciola hepatica is a trematode parasite of farmed livestock with worldwide distribution, causing chronic production losses and possible death from hepatobiliary damage. The effective management of liver fluke infection requires diagnostic tests which can accurately identify infected animals at both the individual and herd level. However, the accuracy of liver fluke diagnostic tests performed on individual New Zealand cattle is currently unknown. The aim of this study was to use a Bayesian latent class model (LCM) to estimate the test characteristics of three liver fluke diagnostic tests, the Coproantigen ELISA, the IDEXX antibody ELISA and the faecal egg count. One hundred and twenty dairy cows each from two dairy farms were blood and faecal sampled in April 2021. The samples were transported to Massey University, Palmerston North, and the three diagnostic tests completed following the respective manufacturer instructions. A Bayesian LCM model, adapted from the original Hui and Walter 2 tests 2 populations model, was built to estimate the test characteristics of the three diagnostic tests in the two dairy herds. The model was implemented in JAGS using Markov chain Monte Carlo sampling. The first 30,000 iterations were discarded as burn-in, and the next 200,000 iterations were used to construct the posterior distributions. Uninformed priors, beta (1,1), were used as the prior distributions for the prevalence estimation and informed beta priors, based on published results, were used as the prior distributions for estimating the sensitivity and specificity of each diagnostic test. Model convergence was confirmed by inspection of trace plots and examination of the results of the Gelman and Rubin test. The results found that the coproantigen ELISA test was the most accurate for diagnosing liver fluke infection in individual animals with a sensitivity = 0.98 (95% CI 0.95 -1.00) and specificity = 0.95 (95% CI 0.81 -1.00) compared to the IDEXX antibody ELISA test, sensitivity = 0.39 (95% CI 0.32 -0.47) and specificity = 0.86 (95% CI 0.75 -0.96) or the FEC, sensitivity = 0.23 (95% CI 0.17-0.30) and specificity = 0.92 (95% CI 0.86 -0.97). Based on these results clinicians should be encouraged to use the coproantigen ELISA test to diagnose liver fluke infection in individual cattle.

Brown kiwi ( Apteryx mantelli Bartlett), a ratite endemic to New Zealand, is currently listed as “Vulnerable” under the IUCN classification system due to predation by introduced mammals. Operation Nest Egg (ONE) raises chicks and juveniles in predator-proof enclosures until they are large enough to defend themselves. These facilities experience an environmental accumulation of coccidial oocysts, which leads to severe morbidity and mortality of these kiwi. Four species of coccidia have been morphologically described from sporulated oocysts with additional opportunistic descriptions of endogenous stages. This research continues the morphological descriptions of these species of Eimeria with an additional novel morphotype also morphologically described. It also provides the first genetic characterisation targeting the mitochondrial cytochrome c oxidase I (COI) gene. Based on these findings, it was determined there are at least five morphotypes of Eimeria that infect brown kiwi and co-infections are common at the ONE facilities surveyed. The COI amplicon targeted for this study was sufficient to provide differentiation from other members of this genus. Sanger sequencing yielded ambiguous bases, indicating the need for more in-depth sequencing.

Cattle fattening using Leucaena (Leucaena leucocephala) as the source or the main component of the cattle’s diets is one of the proven innovations that can provide financial benefit to cattle farmers. The objective of this study is to evaluate the adoption of Leucaena-based cattle fattening and identify the factors contributing to the adoption and diffusion of these improved practices. A mixed method approach was used to understand the adoption of Leucaena and cattle management by local farmers who participated in the early stage (2017) and those who participated in the later stages of the project (2018–2020). The study showed that male Bali cattle (Bos javanicus) that were fed Leucaena-based diets grew two times faster than cattle fattened on grasses. This increased live weight gain and, subsequently, faster sales and increased profits. This may account for the rapid adoption and diffusion of Leucaena-based cattle fattening in Dompu through farmer-to-farmer learning, effective facilitation, demonstration trials, and linking farmers to end markets. To sustain the practice change, the project facilitated the development of an agribusiness support center (ASC). Sustaining the ASC requires further efforts that include internalization of the project outcome into the local government program.

BackgroundNumerous laboratory and fewer field-based studies have found that ixodid ticks develop more quickly and survive better at temperatures between 18 and 26°C and relative humidity between 75% and 94%. Ixodes anatis Chilton, 1904, is an endophilic, nidicolous species endemic to North Island brown kiwi ( Apteryx mantelli, NIBK ) and the tokoeka ( Apteryx australis ) and little is known about the environmental conditions required for its development. Our aims in this study were to determine and compare the conditions of temperature and RH that ensured the best survival, and the shortest interstadial periods for the kiwi tick, in the laboratory and outdoors inside artificial kiwi burrows.MethodsWe collected free walking engorged ticks off wild kiwi hosts and placed them in the laboratory at various fixed temperature and humidity regimes. We also placed sets of different stages of these ticks in artificial kiwi burrows and in both cases, recorded the times taken for the ticks to moult to the next stage.ResultsWe found that larvae and nymphs both showed optimum development between 10-20°C, which is lower than many other species of ixodid ticks. However, larvae moulted quicker and survived better when saturation deficits were <1-2 mmHg (RH>94%) while for nymphs the optimum saturation deficits were 1-10 mmHg.ConclusionsWe believe that the kiwi tick has adapted to stable, but relatively cool and humid conditions in the burrows reflecting the evolutionary consequences of its association with the kiwi.

Monitoring activity patterns of animals offers the opportunity to assess individual health and welfare in support of precision livestock farming. The purpose of this study was to use a triaxial accelerometer sensor to determine the diel activity of sheep on pasture. Six Perendale ewe lambs, each fitted with a neck collar mounting a triaxial accelerometer, were filmed during targeted periods of sheep activities: grazing, lying, walking, and standing. The corresponding acceleration data were fitted using a Random Forest algorithm to classify activity (=classifier). This classifier was then applied to accelerometer data from an additional 10 ewe lambs to determine their activity budgets. Each of these was fitted with a neck collar mounting an accelerometer as well as two additional accelerometers placed on a head halter and a body harness over the shoulders of the animal. These were monitored continuously for three days. A classification accuracy of 89.6% was achieved for the grazing, walking and resting activities (i.e., a new class combining lying and standing activity). Triaxial accelerometer data showed that sheep spent 64% (95% CI 55% to 74%) of daylight time grazing, with grazing at night reduced to 14% (95% CI 8% to 20%). Similar activity budgets were achieved from the halter mounted sensors, but not those on a body harness. These results are consistent with previous studies directly observing daily activity of pasture-based sheep and can be applied in a variety of contexts to investigate animal health and welfare metrics e.g., to better understand the impact that young sheep can suffer when carrying even modest burdens of parasitic nematodes.

There is a desire to increase cattle production on Sumbawa Island but anecdotal reports from farmers indicate that calf mortality can be high. The aim of this paper is to report the occurrence and common causes of calf mortality, as well as to determine if colostral antibody transfer is sufficient in new-born calves. Personal interviews were conducted with 27 farmers. Immunoglobulins were measured in neonatal calves (n=18) using the FASTest IgG Bovine kit. The presence of various pathogens was investigated in fecal samples from calves (n=12) with signs of diarrhea between 1-2 months of age using the FASTest D4T bovine kit and the presence of gastrointestinal parasites was investigated using fecal floatation from pre-weaned calves (3 weeks-3 months of age; n=62). From the questionnaire calf losses ranged from 10–27%, with most losses occurring in older calves. Only one of the 18 calves demonstrated an insufficient concentration of IgG in serum, indicating the possibility of failure of passive transfer from the dam. Of the samples tested from scouring calves, 7 out of 12 samples tested positive for one of the microorganisms causing general diarrhoea in calves. A range of different gastrointestinal nematode parasites were found although very few coccidial oocysts were seen. The results of these studies indicate that calf mortality is high and will be a limitation on the production of beef cattle for slaughter in the Dompu region of Sumbawa Island. Further investigation is required to determine which pathogens are the cause of this calf loss.

Theileria orientalis is a tick‒borne intracellular parasite of red blood cells that causes severe and mild infections in various ruminants worldwide. To date there have been 11 types identified within this species, of which 4 types are presently found in New Zealand cattle. Since 2012, New Zealand has suffered a substantial epidemic of infectious bovine anaemia in both dairy and beef cattle associated with the Ikeda type. The speed at which the disease spread through the North Island suggested that other species could have been involved in transmission. The aim of a series of related experiments was to test the null hypothesis that sheep cannot maintain T. orientalis Ikeda type infection or infect ticks that feed on them. Several studies were conducted over 2 years to address this hypothesis which together showed that sheep can have detectable levels of T. orientalis Ikeda type infection in both the acute and chronic phase and that Haemaphysalis longicornis larvae can become infected when feeding on sheep. No anaemia, weight loss or clinical disease was recorded in the sheep in the acute phase of infection. The levels of infection recorded in the sheep were much lower than those found in cattle, consistent with the sheep being asymptomatic carriers of T. orientalis Ikeda type infection.

Flytraps can be used on farms to monitor the populations of primary strike flies (Lucilia cuprina and Lucilia sericata) and, hence, offer a view regarding the incidence of flystrike on sheep. This study aimed to contrast the specificity and effectiveness of the LuciTrap with its combination of three chemical lures (Lucilures) and the Western Australian Trap with three bait types (LuciLure, Sheep liver with 30% sodium sulphide and squid). A mean model and rate model were fitted to the data. The mean model showed no difference (p > 0.05) in the mean weekly catch for L. cuprina between the Western Australian Trap with LuciLures and the Western Australian Trap baited with sheep liver with 30% sodium sulphide (p < 0.05). Whereas, for L. sericata, no difference (p > 0.05) was found between the Western Australian Trap with LuciLures, the Western Australian Trap baited with sheep liver with 30% sodium sulphide and the LuciTrap. The rate model illustrated that the Western Australian Trap with sheep liver with 30% sodium sulphide and LuciTrap did not differ (p > 0.05) for L. cuprina and L. sericata. Combined, these results indicate that New Zealand farmers can use either the LuciTrap or the Western Australian Trap with sheep liver with 30% sodium sulphide to monitor these target species.

Recent reports indicate that gastrointestinal nematodes (GIN) are contributing to significant losses in deer productivity and that anthelmintic resistance has become an issue of concern for deer farmers in New Zealand. The aim of this study was to evaluate cross-grazing of deer with sheep or cattle as an aid for control of gastrointestinal and pulmonary nematode parasites of farmed red deer (Cervus elaphus) in New Zealand. This was a field study replicated over two years (2012 and 2013) for 16 weeks each year at two locations (Massey University, Palmerston North and Invermay AgResearch Centre, Mosgiel). Each farm replicate included four groups (19-20 deer) at each location: red deer cross-grazing with cattle (Deer/Cattle); red deer cross-grazing with sheep (Deer/Sheep); red deer grazing on their own (DeerOwn); and red deer grazing on their own and treated with anthelmintics every two weeks to suppress worm burdens, as a positive control (DeerSup). The key outcome was the number of anthelmintic treatments (AT) given to deer. The decision to treat individual resident deer in Deer/ Cattle, Deer/Sheep and DeerOwn groups was based on "trigger" criteria including faecal egg count (FEC)>= 250 eggs/g or Dictyocaulus faecal larval count (FLC)>= 100 larvae/g or when growth rate was less than 80 % of the mean of the DeerSup group in the previous two weeks. In addition, to quantify the species of parasites cycling in each group, sets of three "tracer" deer were introduced to graze with each group at the mid-point and again at the end of each 16 week period in both years at both locations. Least squares means (LSM) of the number of AT given per animal for Deer/Sheep (3.4) and DeerOwn (3.3) groups were significantly higher than for the Deer/Cattle (2.7) group (p < 0.001). In tracer animals, the LSM of abomasal Trichostrongylus spp. were significantly fewer in the DeerOwn (17), Deer/Cattle (37) and DeerSup (54) groups than in the Deer/Sheep (952; p < 0.001) group. The LSM of the nematodes in the subfamily Ostertagiinae (=Ostertagia-type) were significantly more in the DeerOwn (1950) than in Deer/Sheep (370; p = 0.003) and DeerSup (238; p < 0.001) groups, but the number in the Deer/Cattle group (689) was not different to DeerOwn (p> 0.05). The LSM of lungworm were fewer in Deer/Sheep (3), Deer/Cattle (4) and DeerSup (3; p < 0.001) groups than in DeerOwn (40) group. The Deer/Cattle and DeerSup groups had significantly higher LSM of liveweight gain over the 16 weeks (p < 0.001) than the other two groups. This study demonstrated that cross-grazing with either sheep or cattle aided control of lungworm and gastrointestinal nematodes in young deer during autumn. However, the advantages varied between the use of sheep or cattle and in the ability to control different species of parasites.

This article sets out to document and summarise the New Zealand epidemic and the epidemiological research conducted on the epizootic of bovine anaemia associated with Theileria orientalis Ikeda type infection, which began in New Zealand in August 2012. As New Zealand has no other pathogenic tick-borne cattle haemoparasites, the effects of the T. orientalis Ikeda type infection observed in affected herds and individual animals were not confounded by other concurrent haemoparasite infections, as was possibly the case in other countries. This has resulted in an unbiased perspective of a new disease. In addition, as both New Zealand's beef and dairy cattle systems are seasonally based, this has led to a different epidemiological presentation than that reported by almost all other affected countries. Having verified the establishment of a new disease and identified the associated pathogen, the remaining key requirements of an epidemiological investigation, for a disease affecting production animals, are to describe how the disease spreads, describe the likely impacts of that disease at the individual and herd level and explore methods of disease control or mitigation.

The aim of this study was to test the hypothesis that toltrazuril administered at 4 weeks post-turnout reduces the infection intensity of Theileria orientalis Ikeda type in dairy calves and so prevents serious clinical disease in these animals at 2-3 months of age. Two groups of 40 dairy calves on two separate dairy farms in the Waikato were followed for 16 weeks post-turnout onto pasture. On each farm, 20 calves were randomly selected and orally treated with toltrazuril (15 mg/kg) at 4 weeks post-turnout, whilst the remaining 20 calves were left untreated. All 40 calves were blood sampled and weighed at 2, 4, 6, 8, 12, and 16 weeks post-turnout i.e. 6 samplings per calf. A random subset of 10 calves from each treatment group on each farm were faecal sampled at each visit. The blood samples were used to estimate the T. orientalis Ikeda type infection intensity and haematocrit for each calf and the faecal samples were used to estimate the number of coccidia oocysts per gram of faeces. Three linear mixed effects models, to evaluate the effect of toltrazuril treatment on infection intensity, haematocrit (HCT) and weight respectively were fitted to the data. No calves on either farm developed clinical theileriosis or coccidiosis and the three mixed effects linear models, controlling for the effect of farm and days from turnout, showed that there was no effect of treatment on infection intensity (p = 0.81), on HCT (p = 0.99) and on weight gain (p = 0.79). In conclusion, this study showed no evidence supporting the use of toltrazuril to control T. orientalis Ikeda type infection levels and prevent disease.

Gastrointestinal nematodes are recognised as an animal health issue for farmed red deer. The aim of this study was to explore the range of species infecting farmed deer herds and their farm-level prevalence in New Zealand. Faecal samples were collected from 12-24-month-old deer (n = 6-26; mean 19) on 59 farms located in the North (n = 25) and South (n = 34) Islands. Sub-samples of faeces were pooled by farm and cultured to recover third stage larvae. Twenty four larvae were randomly selected and identified to species using a multiplex PCR (total = 1217 larvae). At farm-level the most prevalent nematodes were Oesophagostomum venulosum 83% (n = 49) and the deer-specific nematodes in the subfamily Ostertagiinae (=Ostertagia-type) including, Spiculoptera asymmetrica 73% (n = 43), Ostertagia leptospicularis 47% (n = 28), Spiculoptera spiculoptera 47% (n = 28). The recently identified Trichostrongylus askivali was present on 32% (n = 19) of the farms and Oesophagostomum sikae on 17% (n = 10). In the analysis of the total number of larvae identified, the proportion was in similar order, 45% (n = 548) were O. venulosum, 14% (n = 173) S. asymmetrica, 10% (n = 124) S. spiculoptera, 9% (n = 114) O. leptospicularis, T. askivali, 3% (n = 40) and only 2% were O. sikae (n = 20). This study is the first to show the farm-level prevalence of nematode species in deer in New Zealand and the first to use PCR as a diagnostic tool. It provides data consistent with cross-infection from sheep/cattle to deer, and provided tentative insights into the proportions of the main GIN species across the deer population including O. sikae and T. askivali which have only recently been identified in New Zealand.

There is an epidemic in New Zealand of infectious bovine anaemia associated with Theileria orientalis Ikeda type, an obligate intracellular protozoan parasite. To establish whether T. orientalis Ikeda type infection adversely affects fertility of bulls used for natural mating, a randomised controlled experimental study was conducted. Ten of 17 2-year-old Friesian bulls that had not been previously infected with T. orientalis were infected with T. orientalis Ikeda type and then evaluations occurred during a 20-week period. There were semen and libido evaluations every 2 weeks, starting 4 weeks before the date of infection. In addition, there were blood collections, for haematocrit and infection intensity evaluations, rectal temperatures recorded, and bulls weighed three times weekly for 13 weeks after infection and then once weekly until completion of the study. Physical activity meters were also attached from Days 9-60 and 65-124 post-infection. The ten bulls were successfully infected with T. orientalis Ikeda type and this resulted in a decrease in HCT to about 0.25 by 70 days post-infection. There were no effects of infection on semen quality; however, during the acute phase of infection, when the infection intensity was rapidly increasing, the infected bulls took a longer time period for repeated mounting of females, and were less dominant in the herd social heiracrchy. In conclusion, although the transitory effects on libido could reduce conception rates, the overall effects of T. orientalis Ikeda type infection on bull fertility will probably be little.

Coccidia (Eimeria spp.) in brown kiwi (Apteryx mantelli) cause significant morbidity and mortality in captive rearing facilities. Monitoring the abundance of this parasite in individual birds is crucial for successful management of kiwi. This research compares the abilities of centrifugal faecal flotations (CFF) and a modified Mini-FLOTAC protocol to detect oocysts. We hypothesised that the Mini-FLOTAC would detect higher oocyst counts. Kiwi dropping samples (n = 10) were homogenized in MgSO4 (SG 1.28) and oocyst counts made with CFFs and Mini-FLOTAC counting chambers, with three replicates for each method. For CFF, 0.5 g of droppings were examined using standard methods. Mini-FLOTAC counts were made using a modified sample preparation compared with the manufacturer’s protocol but still used a 1:20 dilution of droppings. Oocysts were quantified using light microscopy at ×100–300 magnification. A linear mixed-effects model by REML showed that oocyst per gram estimates via the Mini-FLOTAC method were 3.2 times higher (95% CI 2.4–4.5, p < 0.01) than the CFF results. This increased detection likely represents a more accurate estimation of parasite shedding and should be considered for use in research or applications requiring more accuracy, cost-effectiveness, or accessibility than the CFF provides.

Although currently exotic to New Zealand, the potential geographic distribution of Amblyomma americanum (L.), the lone star tick, was modelled using maximum entropy (MaxEnt). The MaxEnt model was calibrated across the native range of A. americanum in North America using present-day climatic conditions and occurrence data from museum collections. The resulting model was then projected onto New Zealand using both present-day and future climates modelled under two greenhouse gas emission scenarios, representative concentration pathways (RCP) 4.5 (low) and RCP 8.5 (high). Three sets of WorldClim bioclimatic variables were chosen using the jackknife method and tested in MaxEnt using different combinations of model feature class functions and regularization multiplier values. The preferred model was selected based on partial receiver operating characteristic tests, the omission rate and the lowest Akaike information criterion. The final model had four bioclimatic variables, Annual Mean Temperature (BIO1), Annual Precipitation (BIO12), Precipitation Seasonality (BIO15) and Precipitation of Driest Quarter (BIO17), and the projected New Zealand distribution was broadly similar to that of Haemaphysalis longicornis Neumann, New Zealand's only livestock tick, but with a more extensive predicted suitability. The climate change predictions for the year 2050 under both low and high RCP scenarios projected only moderate increases in habitat suitability along the mountain valleys in the South Island. In conclusion, this analysis shows that given the opportunity and license A. americanum could and would successfully establish in New Zealand and could provide another vector for theileriosis organisms.