Austral Journal of Veterinary Sciences
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The Antarctic visitor
Get PDFClimate change is moving a considerable amount of research into several areas of knowledge that were unexpected, for example Chilean research has a program of funding called FONDAP, awarding a grant at FONDAP-IDEAL CENTER and Instituto AntárticoChileno (INACh). These centers will develop research in areas such as oceanography, ecology, genetics and physiology, especially regarding the response to melting iceberg “freshening “ and high temperature. Several animal models will be used to discover what will happen in the future as a result of climate change. Nearly every day, a news report focuses on the changes in the environment and how high temperatures are changing the behaviour-physiology of animals. Also associated with this phenomena is the rise of new economic activities that are increasingly prosperous such as Antarctic tourism, attracting thousands of tourists every year to the frozen continent, with all the anthropogenic implications that this brings. Therefore, not only the impact of having more researchers in the Frozen Continent is increasing but also is the tourism. The ever increasing pressure to be there causes effects on birds like penguins which are more and more accustomed to see to humans and interact among them, while sea lions and elephant seals no longer feel that they are in presence of foreign organisms. This somehow causes the animals to change their ethology expecting some tip, especially the birds. Human pressure from both research and tourism is moving microorganisms such as bacteria to a place where they did not initially exist. In addition, the temperature changecould potentially mobilise some species of fish, crustaceans, mollusks and even echinoderms from the American continent to the Antarctic, or some insects such as mosquitoes. This is important because perhaps not only the effects of high temperature must be considered, but also the increase of human visitors to the Frozen Continent, who may be vectors of some of the invertebrates/microorganisms mentioned above. Although grants are needed for research, in this case we must be aware that our movements will always have a consequence, and now that tourism is an important source of business for some companies we should be careful and take measures so as not to carry uninvited animals (microorganisms-invertebrates) to the White Continent
Effect of the inclusion of herbal phosphatidylcholine on palatability, digestibility and metabolisable energy of the diet in dogs
Get PDFThis study aimed to evaluate the palatability, nutrient digestibility, metabolisable energy (ME) and faecal characteristics of diets in dogs fed increasing levels of herbal phosphatidylcholine (herbal mix) versus an unsupplemented diet (with only 377 mg choline provided by 1 kg food) or choline chloride (2000 mg choline/kg food) in 40 adult dogs. In experiment 1, a palatability test was conducted to make two pairwise comparisons: 0 versus 200; and 0 versus 400 mg/kg herbal mix. In experiment 2, a digestibility test was performed to evaluate herbal mix at 0, 200, 400 and 800 mg/kg and 2000 mg choline provided by choline chloride. Results from experiment 1 indicated that the dogs preferred diets containing herbal mix to the unsupplemented diet (P<0.05). In experiment 2, nutrient digestibility and faecal characteristics were not influenced by the treatment (P<0.059). The inclusion of 400 mg/kg of herbal mix increased the ME (quadratic effect, P<0.01). In conclusion, the results of this study indicate that the inclusion of a herbal mix rich in phosphatidylcholine (1.6%) and other methylated metabolites at 400 mg/kg can fully replace choline chloride in dog diets
Dairy cow behaviour around calving: Its relationship with management practices and environmental conditions
Get PDFCalving is one of the most challenging and painful experiences for dairy cattle and a process that involves coping with physical and physiological changes, as well as environmental and management-related stressors. In recent years, it has been argued that the application of cow behaviour knowledge might facilitate their efficacious management during calving. This review aims to summarise and discuss current knowledge regarding the behavioural changes that occur around calving time. The relationship between calving behaviour, management practices, and environmental conditions in dairy cattle raised in intensive indoor production systems, as well as pasture-based systems, is also discussed. First, we briefly outline the process of parturition and the concept of maternal behaviour. We then describe behavioural changes that occur around parturition in normal and dystocic births and how variations in these behaviours can be used to predict normal or assisted calving in dairy cattle; particular emphasis is placed on the role of feeding, rumination, and lying behaviour. Finally, we review how management practices and environmental conditions can influence cow’s behaviour at calving and discuss the importance of providing an environment that accommodates the behaviour they are motivated to perform. This review presents evidence that the time a cow is moved to the calving area, the type of group housing and the provision of a secluded area to calve, can impact the behavioral responses of dairy cows at calving. Evidence regarding the effects of exposure to environmental conditions such as heat during summer, and/or cold, wet and mud during winter can also have a negative impact on behaviour, suggesting potential benefits of providing cows with a protected area to calve. We conclude that a better understanding of the behaviour of parturient cows may help producers improve the care and management around calving time
Infectious bronchitis virus variants in chickens: evolution, surveillance, control and prevention
Get PDFInfectious bronchitis is a disease of the upper respiratory tract of chickens caused by a Gammacoronavirus (infectious bronchitis virus, IBV). Severe economic losses are caused by IBV due to a reduction in egg production and/or egg quality in layers in addition to poor feed conversion and increased condemnations in broiler chickens. The extreme variability of this virus is in part due to its RNA genome, which predisposes it to mutations and generates genetic variation. In addition, recombination events add to the variability of this virus. IBV variability was first described in 1956 by Jungherr. Since then, dozens of serotypes and hundreds of genotypes have been reported. Variant IBV strains are those that, can escape from the immunity generated by conventional strains, despite not being fully different from conventional strains affecting a geographic region. At the genomic level, these differences can be equal or greater than 5% of the hypervariable region of the S1 gene. These variant strains are usually restricted to geographic regions and most of the time are transient, reason why diagnostics and epidemiological surveillance are crucial to determine their existence and persistence. The main goal of surveillance is to assist the development of efficient preventative measures in the field. This review aims to critically analyse the literature related to IBV variability and judiciously comment and discuss on how to better prevent this poultry endemic disease
Checklist and state of knowledge of helminths in wild birds from Chile: an update
Get PDFHelminths are an important component of biodiversity with over 24,000 species parasitising wild birds globally, with this figure on the rise given the growing interest in wildlife parasitology. The present study aimed to establish an updated baseline of the helminthological surveys on wild birds from Chile. Available publications were reviewed to build a parasite-host association checklist and also to discuss the state of knowledge regarding these parasites. A total of 92 publications were found between the years 1892 and 2019. Regarding helminth parasites, 174 taxa belonging to 3 phyla and 37 families were recorded, 114 taxa were identified at species level, with the rest remaining incompletely described. Also, 4 taxa corresponded to new genera and 16 to new at species for science. The most reported parasites were platyhelminthes (53.9%) followed by nematodes (36.2%) and acanthocephalans (9.2%). Sixty-five avian species from 19 orders have been recorded as hosts, with most of them having been studied only once (64.6%). Out of these, the order Charadriiformes had the highest number of publications (n=23). In the case of the avian species present in the country, 14.2% of native, 40% of endemic and 22.2% of exotic species have been recorded hosting helminths. Regarding heteroxenous parasites, only 2 species have had their life cycles elucidated. Among the methodologies used for parasitic identification, 48.9% of the studies used morphological tools, 5.4% used molecular tools and 4.3% used both tools. For that reason, there are evident gaps in the data concerning the hosts sampled, methodologies and issues related to the biology of parasites such as life cycles, among others. In this sense, the need for specialists and cooperative research becomes indispensable to improve our understanding of helminths
Vol.51 - 2 - 2019: Cover: Micrograph showing fluorescent merocyanine patterns on dog spermatozoa: opaque - low fluidity (spermatozoon on the left) or brilliant - high fluidity (spermatozoa on the right). Photograph captured by Alicia Alcantar-Rodríguez and provided by Ortega-Morales et al.
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Mycoplasmal infection in a guigna (Leopardus guigna) from central Chile
Get PDFRoutine blood analysis indicated the presence of Mycoplasma-like bodies in a guigna (Leopardus guigna). Evidence of infection with Candidatus Mycoplasma haemominutum was found in blood samples using PCR and DNA sequencing of the 16S rRNA gene of Mycoplasma. Mycoplasma spp. are documented in cats but their role in the transmission of Mycoplasma to guigna populations requires investigation