Duration of immunity, efficacy and safety in sheep of a recombinant Taenia ovis vaccine formulated with saponin or selected adjuvants.

The efficacy and safety of a recombinant Taenia ovis protein was tested in sheep using 13 different adjuvant formulations, including oil adjuvants, aluminium salts, saponin, Iscoms and DEAE-dextran. The oil adjuvants, saponin and DEAE-dextran gave the highest antibody responses and greatest degree of protection against challenge infection with T. ovis eggs. Duration of immunity studies with a saponin based vaccine showed that highly significant protection (>90% reduction of cyst numbers) was achieved when sheep were challenge infected one month after immunisation. Significant protection (79%) was still present when sheep were challenged 6 months after immunisation. The optimum dose for this batch of saponin was 10 mg, which stimulated a peak antibody titre of 38,400, 4 weeks after immunisation and did not cause injection site reactions. Dialysed saponin was shown to retain its adjuvant properties and allowed an increase in dose to 30 mg without site reaction, resulting in a peak antibody titre of 51,200.     

Distribution and abundance of overwintering Calanus finmarchicus in the Faroe–Shetland Channel

The distribution and abundance of overwintering Calanus finmarchicus in the Faroe–Shetland Channel was studied during December 1994 and January 1995. Maximum abundance of animals in the Channel was approximately 50 000 m⁻², with a peak concentration of 627 m⁻³ at a depth of 930 m. Copepodite stages IV and V accounted for > 98% of the population. A clear association was found between the horizontal and vertical distribution of animals and the Arctic water masses in the bottom of the Faroe–Shetland Channel. The Wyville–Thomson Ridge formed a barrier to the southern distribution of Arctic waters and the abundance of overwintering C. finmarchicus was 25 times lower to the south of the Ridge than to the north. Spatial variability in lipid content and composition indicated that overwintering C. finmarchicus in the southern Norwegian Sea were in poorer condition with respect to wax ester content, and in a more advanced state of emergence from overwintering, than the animals within the Channel. The overwintering stock in the Channel probably originated from the Norwegian Sea or from north of the Faroe Islands. The Faroe–Shetland Channel is an important source of animals advected into the northern North Sea in the spring (March/April). The population abundance in the Faroe–Shetland Channel was estimated to be 4.5 × 10¹⁴ individuals, which is more than adequate to account for the mean concentration of adult stages observed in the northern North Sea in April.     

Seasonal changes in respiration rates of copepodite stage V Calanus finmarchicus (Gunnerus)

Copepodite stage V Calanus finmarchicus were collected at locations on the continental shelf north of Scotland, in the Faroe–Shetland Channel and west of Ireland on six occasions covering winter, spring and summer from October 1993 to June 1995. Oxygen consumption by the overwintering and active spring/summer population of animals was determined at temperatures close to in situ temperatures. Laboratory measurements of oxygen consumption were also made at standardized temperatures (0°C, 5°C, 7°C and 12.5°C) to determine the sensitivity of animals to temperature change in the different seasons. Rates of oxygen consumption were very low (7–30 μmol O₂ gC⁻¹ h⁻¹) at in situ temperatures during the winter and early spring and significantly higher (105–219 μmol O₂ gC⁻¹ h⁻¹) for the active surface population in May and June. Animals collected from the overwintering population showed no significant response to changes in temperature. Due to the low respiration rates, the calculated rate of decrease in carbon content in diapausing copepodite stage CV was very low (approximately 0.250 μgC day⁻¹). The respiration rates were used to construct a model to estimate survival of the animals with an initial carbon content equivalent to that expected of animals in October. The results showed that in order to survive during winter and have enough energy for moulting and migration to the surface in the spring, these animals have to live at temperatures close to 0°C and be in a diapause state.     

Updated distribution and host records for the argasid tick Ornithodoros (Pavlovskyella) zumpti: A potential vector of African swine fever virus in South Africa

African swine fever virus (ASFV) causes a lethal and contagious disease of domestic pigs. In South Africa, the virus historically circulated in warthogs and ornithodorid ticks that were only found in warthog burrows in the north of the country. Regulations implemented in 1935 to prevent transfer of infected animals or products to the south initially proved effective but from 2016 there have been outbreaks of disease in the south that cannot be traced to transfer of infection from the north. From 1963 there were widespread translocations of warthogs to the south, initially from a source considered to be free of ornithodorid ticks. We undertook to determine whether sylvatic circulation of ASFV occurs in the south, including identification of potential new vectors, through testing extralimital warthogs for antibody and ticks for virus. Results of testing warthogs for antibody and other species of ticks for virus will be presented separately. Here we report finding Ornithodoros (Pavlovskyella) zumpti ticks in warthog burrows for the first time. This occurred in the Eastern Cape Province (ECP) in 2019. Since African swine fever was recognised in the ECP for the first time in 2020 and outbreaks of the disease in domestic pigs continue to occur there, priority should be given to determining the distribution range and vector potential of O. (P.) zumpti for ASFV.     

The Effect of Diet on the Energy Budget of the Brown Sea Cucumber,Stichopus mollis (Hutton)

This study investigated the ability of the brown sea cucumber, Stichopus (Australostichopus) mollis, to grow on diets made from aquaculture waste. Weight‐standardized rates (ingestion, assimilation, respiration, ammonia excretion, and fecal excretion) of small (juvenile), medium (mature), and large (mature) sea cucumbers were measured and energy budgets constructed to quantify their growth rates when offered three different diets at 14, 16, and 18 C. Three types of diet were offered: uneaten abalone food (diet A) and two types of abalone feces, one where abalone were fed 50% Macrocystis pyrifera and 50% Undaria pinnatifida macroalgae (diet B) and the other where abalone were fed 25% M. pyrifera, 25% U. pinnatifida, and 50% Adam & Amos Abalone Food, where the latter is an industry standard diet (diet C). The organic contents of the diets were much higher than natural sediments and varied such that diet A (76.40%) > diet B (54.50%) > diet C (37.00%). Diet had a significant effect on S. mollis ingestion rates, assimilation efficiencies, and consequently energy budgets and growth rates. Greater quantities of organic matter (OM) from diet A and diet B were ingested and assimilated by the sea cucumbers compared with the OM in diet C. The energy budgets indicated that after taking routine metabolism into account, all sizes of sea cucumbers had energy to allocate to growth when offered diet A and diet B, but only juveniles had energy to allocate to growth when offered diet C. Fecal excretion rates when offered diet A and diet C at 14 C were greater than those at 18 C, but neither was significantly different from that at 16 C. Ammonia excretion rates increased nonlinearly with temperature for small and medium sea cucumbers but not for large sea cucumbers. Weight‐standardized respiration rates increased with temperature and unexpectedly with animal size, which may have been because of the narrow weight range of test animals biasing the results. These results suggest that industry standard type abalone waste lacks sufficient energy to meet the metabolic requirements of mature sea cucumbers but that growing juveniles on these wastes appears to be feasible and warrants further investigation.     

The role of lectures in veterinary education

OBJECTIVE: To study the role of lectures from the perspective of staff and students involved in the veterinary course at The University of Queensland. METHODS: The Nominal Group Technique of Delbecq et al, which provides the maximum opportunity for group members to put forward points, was used to help develop a questionnaire which was completed by 351 students (a response rate of 84%) and 35 staff (76%) from the five years of the veterinary course, and was analysed using the SAS System for Windows. RESULTS: Almost all the staff and students agreed that lectures should fulfil many roles including stimulating and motivating students and encouraging them to think, as well as presenting ideas and concepts and an indication of the structure and relevance of the material. They should provide a guide for effective deep learning, but not encourage rote (or superficial) learning. A smaller percentage of staff and even fewer students agreed that lectures did fulfil these roles, especially those directed at encouraging students to look beyond simple memorisation of facts. The perceived disparity between reality and the ideal was greater amongst the older, clinical students than amongst their more junior colleagues. CONCLUSIONS: The focus of attention in lectures needs to change from the superficial, rote learning of information to deep, active learning directed at using information to solve problems that are perceived by the students to be relevant. If done in a stimulating and interesting way, this should develop skills in reasoning and critical analysis as well as providing a framework for storage and recall. It should also increase the motivation towards learning both during the veterinary course, and over the professional lifetime. Furthermore, the place of the lecture in veterinary education needs to be reassessed regularly in the face of newly-emerging educational technology.     

Flystrike in New Zealand: An overview based on a 16-year study, following the introduction and dispersal of the Australian sheep blowfly, Lucilia cuprina Wiedemann (Diptera: Calliphoridae)

A summary and analysis have been carried out on data from over 6000 instances of flystrike in sheep in NZ, over a 16-year period, using a self-referral system where farmers submitted larvae and related information. The study covered a period of establishment and subsequent countrywide spread of the exotic blowfly, Lucilia cuprina. Comparisons are drawn between flystrike as it was perceived by surveys carried out before the 1940s, and the current situation with L. cuprina as an added major impediment. Briefly, the main differences are an increase in the prevalence of flystrike, changes in the representation and relative influence of individual primary blowfly species, an extension of the flystrike 'season', and an apparent increase in the importance of footrot as a factor predisposing to flystrike. Otherwise, flystrike is still primarily a disease of ewe lambs that are struck predominantly around the tail and perineum, mainly because of faecal staining.