Austral Journal of Veterinary Sciences
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The biological basis of smoltification in Atlantic salmon
Get PDFChile is the second-largest producer of Atlantic salmon in the world, and the Chilean salmon production accounts for 27% of the world’s production. One important step of the productive cycle in freshwater is the smoltification process that prepares the fish for the marine life stage. This review describes the biological basis of smoltification in Atlantic salmon, with particular attention on branchial osmoregulatory adaptations. We also discuss some of the infectious diseases and problems in smoltification (two of the main causes of losses in Chilean aquaculture) that could be related from a physiological point of view
Mycoplasma isolation in milk samples from dairy herds in Chile
Get PDFMycoplasma bovine mastitis is a highly contagious disease, usually associated with clinical cases refractory to antibiotic treatment. The aim of this study was the isolation of Mycoplasma species in cattle milk samples from dairy herds in Chile. Bulk tank milk samples selected by convenience from 91 Holstein Friesian dairy herds located in Los Rios (66) and Los Lagos (25), the two most important dairy Regions in the country, were collected. Additionally, 100 individual milk samples from cows with a high incidence of clinical mastitis, refractory to antibiotic therapy, and negative bacteriological results for traditional mastitis pathogens, all from the Biobío Region and received in our diagnostic laboratory, were included. All samples were cultured for 10 days on PPLO medium. The differentiation of suspect colonies between genus Mycoplasma and Acholeplasma was performed by the digitonin test and a specific PCR. The species identification was performed by a M. bovis specific PCR and 16S rRNA sequencing. Mycoplasma was isolated from 3 (3.3%) bulk tank milk samples and 2 (2%) individual cow milk samples. All colonies were identified as Mycoplasma by the digitonin test and by a specific PCR. At species level, one strain isolated from a bulk tank milk sample was identified as M. bovis. The remaining two strains isolated from bulk tank milk samples were identified as M. bovigenitalium, while the two strains isolated from milk of individual cows were identified as M. alkalescens. These results show that not only M. bovis is present in Chilean dairy herds, but also other pathogenic species not previously described in Chile such as M. bovigenitalium and M. alkalescens, which pose a potential risk for dairy herds in southern Chile
Ultrasonographic study of the right coronary artery in performance horses
Get PDFHistorically, echocardiography has focused on the assessment of cardiac dimensions and indices of cardiac function. However, when referred to ultrasonographic coronary arteries characterisation in the horse, information is scarce. The purpose of this study was to describe the right coronary artery in both long and short axis and to analyse its variability between horses with different levels of performance. Sixty healthy horses were included in the study. The animals were eventing horses at different levels of performance and were allocated into two groups according to their athletic level. The internal lumen diameter and the area of the right coronary artery (RCA) were measured in the right parasternal long and short axis views in the 3rd and 4th intercostal space respectively, during systole and diastole. The results were compared between groups using the analysis of variance (ANOVA) and Student’s t-test. The correlation between the physiological parameters and the RCA was assessed using the Pearson correlation coefficient. Statistically significant differences were found when the RCA internal diameter was assessed between groups in both short and long axis. There were no statistically significant differences intra-group when short and long axis measurements were compared between each other. A positive correlation was observed between RCA and age, height, left atrium diameter, aortic valve diameter, sinus of Valsalva diameter, and aorta diameter. In conclusion, the level of training might affect the ultrasound measurement of the RCA in sport horses. Non-invasive echocardiography can be used to consistently assess the size of the right coronary artery in athletic horses in both short and long axis
Effects of Moringa oleifera and Brosimum alicastrum partial feed substitution in intramuscular fat and adipose tissues and on the expression of lipogenic genes of Mexican hairless pigs
Get PDFThe present study evaluated the effects of the inclusion of ground Moringa oleifera and Brosimum alicastrum leaf meal in the diet of Mexican hairless pigs (MHP) on the amount of intramuscular fat, subcutaneous fat, leg muscle (Biceps femoris) fat, loin muscle (Longissimus dorsi) fat, leg and back fat, and the expression of lipid metabolism genes. Hairless pigs are reared in the Mexican tropics and are characterised by their body and intramuscular fat accumulation. Eighteen male pigs fed for 82 d were randomly allotted to three experimental isoenergetic and isoproteic diets, where M. oleifera or B. alicastrum (six pigs per diet) replaced wheat bran. The diets used were a control diet, a diet with 10% M. oleifera leaf meal, and a diet with 10% ground B. alicastrum leaf meal. The M. oleifera diet decreased (P<0.05) the fat ratio in the Longissimus dorsi muscles, back fat, rib fat, total carcass fat, and the carcass fat: meat ratio. The B. alicastrum diet only decreased fat in the Biceps femoris muscle, back fat, and rib fat. Moringa oleifera and B. alicastrum diets also promoted the overexpression of mRNA from the stearoyl-CoA desaturase (SCD), fatty acid synthase (FASN), acetyl-CoA carboxylase alpha (ACACA), sterol regulatory element-binding protein 1 (SREBP1) and acyl carrier protein (ACP) lipogenic genes in the Biceps femoris muscle and leg fat (P<0.001). In addition, lower ACACA and SREBP1 mRNA expression in the Longissimus dorsi muscle and back fat (P<0.001) were related to the lower amount of fat in pigs fed M. oleifera and B. alicastrum. The inclusion of Moringa oleifera and Brosimum alicastrum meals 10% in the diet of the pig MHP reduces fat, this is an important finding because fat is abundant in this type of pig
Vol. 51 - 3 - 2019: Cover: Leishmania amastigote forms inside a macrophage from a bone marrow sample. Image provided by Spinelli et al.
No full textComplete issue (September 2019
Gurltia paralysans: a neglected parasite of domestic cats
Get PDFGurltia paralysans (order Strongylida; family Angiostrongylidae) is a metastrongyloid parasite that causes chronic meningomyelitis in domestic cats in South America. The geographic distribution of G. paralysans includes rural and peri-urban areas of Chile and Argentina. However, feline gurltiosis has recently been reported in other South American countries, including Uruguay, Colombia, and Brazil, and was also recently reported in Tenerife, Canary Islands (Spain). Feline gurltiosis is increasingly detected in domestic cats in southern Chile and its apparent geographic range is also increasing, together with an awareness of the disease among veterinarians. The life cycle of the parasite is unknown, but is probably indirect, involving gastropods as the intermediate host, as in other metastrongyloid nematode species. The clinical signs of G. paralysans infection include progressive pelvic limb ataxia, paraparesis, paraplegia, faecal or urinary incontinence, and/or tail paralysis. A definitive diagnosis of feline gurltiosis is still challenging and only possible with necropsy, when adult G. paralysans nematodes are detected within the spinal cord vasculature, together with macroscopic lesions, and characteristic morphological features. A semi-nested PCR method was recently developed for the in vivo diagnosis of this neglected parasite. Current treatment options include macrocyclic lactones and mylbemicn oxime, but the prognosis is poor in severe cases. In this article, we review G. paralysans infection in cats, focusing on the diagnosis shortcomings and the future directions of research into its biology and the associated neurological disease. Comprehensive updates on the epidemiology and clinical features, diagnosis, treatment, and prevention of feline gurltiosis are provided
Metabolic response to water shortage in an isolated feral sheep population
Get PDFTo establish metabolic responses for biochemical analytes related to freshwater shortage adaptation, a total of 376 blood samples were collected from feral sheep at the Socorro Island, Revillagigedo Archipelago. Comparisons were made between four sampling periods with repeated measurements at 0, 7, 14, and 21 d (94 blood serums: 84 females and 10 males). During the first week, the sheep received daily water ad libitum. During the second and third week, the sheep received 60% daily water in relation to the first 7 days intake. Analysis of variance was used to compare the mean values between sampling days. Stepwise regression analysis was used to evaluate the relationships between the biochemical analytes. The glucose (GLU), total cholesterol (COL-T), triglycerides (TAG), urea, albumin (ALB), total protein (PROT-T), sodium ion (Na+), creatine kinase (CK), arginine vasopressin (AVP), and aldosterone (Aldo), were determined. With the exception of GLU, the COL-T, TAG, urea, ALB, PROT-T, Na+, CK, AVP, and Aldo showed differences between sampling days with the higher values corresponding to 14 d with limited water intake. Negative correlations (P<0.05) between ALB with COL-T and TAG, were quantified. Positive correlations (P<0.05) between COL-T with TAG, and Aldo; between urea with PROT-T, between CK with ALB and PROT-T, between AVP with COL-T, TAG, urea, PROT-T and Aldo, and between Aldo with Na+, were quantified. Results could help improve the accuracy of metabolic profiles used as a tool for evaluating dehydration indicators and to describe the physiological mechanisms employed by feral sheep to cope with limited availability of freshwater
Is the effectivity of copper ions treatment of milk enough to block Mycobacterium avium subsp. paratuberculosis infection in calves?
Get PDFMilk is an important transmission route of Mycobacterium avium subsp. paratuberculosis (MAP) for dairy calves. Given its resistance to pasteurization, alternative milk treatments are needed to control MAP transmission via milk. The present study reports the evaluation of a novel milk decontamination treatment based on copper ions as a means of preventing infection in dairy calves. Ten newborn calves were assigned to one of two experimental groups (n=5) which were studied for 1 year. The first group was fed milk naturally contaminated with MAP and the second one received the same milk but after being treated with copper ions. In both groups, milk MAP load was estimated. The progression of the infection was monitored monthly and at the end of the study, calves were euthanised, and tissue samples were examined both grossly and by histopathology. The treatment of milk with copper ions significantly reduced the number of viable MAP. Faecal shedding of MAP was observed in both study groups, but the calves fed naturally contaminated milk began to shed MAP earlier. Only calves fed copper-treated milk showed histopathological evidence consistent with MAP infection. The latter offers more questions than answers, and maybe the presence of a more tolerant and virulent MAP strain could be the final answer to this situation
Vol. 53 - 1 - 2021 - Special Issue: Half-century spreading veterinary sciences
No full textSpecial Issue: Half-century spreading veterinary science