Journal of Veterinary Research最新文献

Introduction: Ticks are obligate blood-feeding arthropods that cause significant economic losses in domestic animal husbandry and threaten public health. However, information about soft ticks (Acari: Argasidae) and tick-borne pathogens in the Xinjiang Uygur Autonomous Region (XUAR) of China is scarce.

Material and methods: In this study, PCR assays and gene sequencing were used to detect and analyse the epidemiological features of Anaplasma ovis, Theileria ovis and Brucella abortus parasitic infections in 366 Ornithodoros lahorensis soft ticks collected from five sampling sites in the XUAR from October 2019 to March 2022. The ticks were identified by morphological and molecular methods as O. lahorensis. The PCR was conducted using primers complementary to the major surface protein 4 (Msp4) gene of A. ovis, the 18S ribosomal RNA (18S rRNA) of T. ovis and the outer membrane protein 22 (Omp22) gene of B. abortus.

Results: The overall infection rate was 91/366 (24.9%) for A. ovis, 127/366 (34.7%) for T. ovis and 94/366 (25.6%) for B. abortus. Sequencing analysis indicated that A. ovis Msp4, T. ovis 18S rRNA and B. abortus Omp22 genes from XUAR isolates showed 99.58-100% identity with documented isolates from other countries.

Conclusion: This study provides fundamental evidence for the occurrence of A. ovis, T. ovis and B. abortus in O. lahorensis. Therefore, the potential threat of soft ticks to livestock and humans should not be ignored. This study expands the understanding of the existence of tick-borne pathogens in O. lahorensis and is expected to improve the strategies for prevention and control of ticks and tick-borne diseases in China.

Introduction: Apart from their antioxidant activity, plant-derived bioactive compounds can also positively affect the quality of meat and meat products by improving their sensory and microbiological properties and preventing discolouration. The aim of this study was to determine how the addition of different forms of rosemary improved the quality of pork.

Material and methods: Minced pork samples were divided into a control sample without additives (C) and three experimental samples with certified additives (15 mg/kg of meat each), i.e. rosemary oleoresin (ROL), extract (REX) and essential oil (REO). Each was further divided into three subsamples; the first was evaluated before storage, and the second and third were evaluated after respective 7- and 14-day vacuum-packed storage at 2°C. The TBARS value was expressed as mg of malondialdehyde (MDA) per kg of meat. Colour was determined based on the values of the standard colour space values of L* (lightness), a* (redness) and b* (yellowness) as well as C* (chroma) and h° (hue angle). Sensory attributes of the samples were evaluated on a nine-point scale. The pour-plating procedure was used for the enumeration of Pseudomonas, mesophilic lactic acid bacteria, psychrotrophic bacteria and rods of the Enterobacteriaceae family. Within each bacterial group, the most common colonies were identified by matrix-assisted laser desorption and ionization (MALDI).

Results: Lipid oxidation was most effectively inhibited by REO. The addition of ROL and REO to pork lightened its colour. Meat with REO had stronger redness, whereas meat with ROL had stronger yellowness. The addition of REX affected the sensory properties of pork most beneficially. Neither Enterobacteriaceae nor Pseudomonas spp. were detected in REO pork, which also contained lower counts of lactic acid bacteria than group C pork.

Conclusion: The results of this study indicate that rosemary has antioxidant and antimicrobial properties, and may improve the colour and sensory attributes of pork. The effect exerted by rosemary on meat quality may vary depending on the physical form of the additive.

Introduction: Chokeberry pomace, rich in polyphenolic compounds, holds potential to be a valuable feed additive for enhancing the antioxidative capacity and overall quality of milk. This study explores the impact of dietary inclusion of chokeberry pomace on oxidative stress parameters and other milk quality parameters in high-producing dairy goats.

Material and methods: Twenty-seven goats were allocated into three groups: a control group provided standard feed and two experimental groups provided feed supplemented with 15 g or 30 g of chokeberry pomace per kilogram. Milk samples were analysed for physicochemical traits, a range of enzyme activities and antioxidant properties.

Results: Supplementation with chokeberry pomace significantly reduced milk fat content, enhanced antioxidative properties and increased most of the quantified enzyme activities. Total polyphenol content and reduced glutathione levels were significantly higher in the supplemented groups, correlating with improved antioxidative potential of the milk.

Conclusion: Chokeberry pomace in goat diets enhances milk's antioxidative properties and upregulates its enzymatic activity profile, suggesting a potential strategy to improve the nutritional quality and health benefits of goat milk. The study underscores the utility of chokeberry pomace as a feed additive that might not only benefit animal health but also contribute to enhanced milk quality.

Introduction: How bacterial infections of the reproductive tract cause infertility and the correlation between the health status of female dogs and the presence of Mycoplasma canis (M. canis) in the vagina are still unclear. The aim of this study was to determine the M. canis population in the vagina of breeding bitches and to correlate this microbial population with some fertility outcomes.

Material and methods: A total of 275 breeding bitches were included in the study. Vaginal samples were collected for microbiological and PCR testing.

Results: Mycoplasma canis was identified in 34.91% of the samples. One-third of bitches from the problem-free group and 41.18% from the group with problems were positive. In general, there were no significant differences in the prevalence of M. canis between the groups (P-value > 0.05). Mycoplasma canis occurs in both mated and unmated bitches and was found in a large number of kennels (67%). There was a correlation between M. canis in the kennel and the incidence of single puppy deaths and low litter sizes. There was also some correlation between the presence of M. canis in the vagina with at least two other bacterial strains and reproductive disorders.

Conclusion: Our results indicate that M. canis is part of the normal vaginal flora of breeding bitches, although a role for this bacterium in causing some reproductive disorders remains to be disproved.

Introduction: Dirofilaria repens is a zoonotic parasitic filarial nematode that infects carnivores and occasionally humans. Knowledge of the host-parasite molecular interactions enabling the parasite's avoidance of the host immune response in subcutaneous dirofilariasis remains limited. Parasitic orthologues of host macrophage migration inhibitory factor (MIF) are molecules potentially involved in this process.

Material and methods: Complementary DNA encoding two D. repens MIF orthologues (rDre-MIF-1 and rDre-MIF-2) was cloned into a pET-28a expression vector. The recombinant proteins were produced in Escherichia coli and purified using affinity nickel chromatography. The reactivity of both recombinant proteins was analysed with infected dog and immunised mouse sera.

Results: Stronger antibody production was induced by rDre-MIF-1 in mice, as evidenced by significantly higher levels of anti-rDre-MIF-1 total IgG, IgG2 and IgE antibodies than of anti-rDre-MIF-2 immunoglobulins. Additionally, a significantly different level of antibodies specific to both proteins was noted between the sera of infected dogs and those of uninfected dogs.

Conclusion: This study is the first attempt to characterise MIF orthologues from the filarial parasite D. repens, which may affect the immune response during infection.

Introduction: This study aimed to evaluate biomarkers of oxidative stress (2-thiobarbituric acid reactive substances, aldehyde and ketone derivatives of oxidatively modified proteins and total antioxidant capacity), the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase), that of lysosomal enzymes (alanyl aminopeptidase, leucyl aminopeptidase, β-N-acetylglucosaminidase and acid phosphatase) and changes in biochemical parameters (alanine aminotransferase, aspartate aminotransferase, de Ritis ratio, lactate dehydrogenase activity, lactate and pyruvate levels and their ratio) in the liver tissue of fish that were vaccinated against enteric redmouth disease and challenged with its causative agent, the bacterium Yersinia ruckeri.

Material and methods: The vaccine was administered orally to trout, some of which were challenged with Y. ruckeri 61 days later. For comparison, unvaccinated and unchallenged trout and unvaccinated and challenged trout were also evaluated.

Results: In the unvaccinated fish, infection with Y. ruckeri disrupted the pro-oxidant/antioxidant balance, led to a significant increase in lipid peroxidation and oxidative modification of proteins, decreased total antioxidant capacity and significantly increased the activity of lysosomal enzymes. In vaccinated fish, the Y. ruckeri challenge increased the activity of glutathione-related enzymes and decreased lipid peroxidation, anaerobic metabolism and the activity of lysosomal enzymes in fish livers relative to the unvaccinated and challenged group. In contrast, these parameters increased after the Y. ruckeri challenge in unvaccinated trout relative to those in the untreated group.

Conclusion: Vaccination exerted a protective effect during the Y. ruckeri challenge and had no adverse effect on fish livers.

Introduction: Perfusion index (PI) is used as assessment of epidural anaesthesia efficacy in human medicine, but its usefulness in dogs is unknown. The aim of this study was to evaluate the usefulness of PI in determining epidural anaesthesia effectiveness.

Material and methods: This is prospective cross-over experimental study. Five healthy adult beagle dogs were anaesthetised and an epidural catheter was inserted in the lumbosacral area and adjusted so that the end of the catheter was placed at the fourth lumbar vertebra. Single-port catheters were used in the control group and multiple-port catheters were used in the treatment group. A PI probe was placed on a hind leg, and the catheter placement was confirmed via computed tomography. The treatment group received a bolus dose of lidocaine, and the control group received saline, via epidural catheter. The PI value was recorded every 5 min until 30 min after lidocaine injection.

Results: The PIs of the hind limbs were not significantly different over time, nor were they between the control and lidocaine-injected groups at any point in time.

Conclusion: The PI is not useful in determining the efficacy of epidural anaesthesia in dogs under general anaesthesia. In the future, finding a reliable method to evaluate the success of regional anaesthesia, even in patients under general anaesthesia, will be necessary.

Introduction: Using coffee husks as waste material for bedding contributes to sustainable development. A sustainable choice of bedding has also, however, to be a safe choice for poultry. The study analysed immune-related gene expression in the intestinal mucosa and indicator bacteria in caecal content collected from broiler chickens bedded on material with coffee husk addition.

Material and methods: One-day-old Ross 308 chickens were divided into four groups of 10 birds each in five replicates: C, the control group kept on wheat straw bedding; CH10, a group kept on bedding of 10% coffee husks and 90% wheat straw; CH25, a group kept on bedding of 25% husks and 75% straw; and CH50, a group kept on bedding of 50% husks and 50% straw. After 42 days, the birds were slaughtered, the caecal mucosae were removed for RNA isolation and the caecal content was collected for bacterial DNA isolation. The expression of genes involved in intestinal immune response and host organism defence and the relative abundance of indicator bacteria were analysed.

Results: Upregulation of the expression of genes related to the immune response and intestinal tightness was correlated with an increase in the percentage of coffee husks in the pellet. Coffee husk pellets at 50% bedding content caused a significant numerical increase in Bifidobacterium and a statistically significant increase in Lactobacillus. A significant reduction in E. coli bacteria was also demonstrated in this group. Coffee husk pellets at all content percentages resulted in a statistically significant diminution of the level of Streptococcus bacteria.

Conclusion: The addition of coffee husks to poultry litter effects beneficial changes in the expression of genes related to intestinal health and the caecal bacterial profile.

Introduction: This study aimed to determine the bacterial diversity of chicken carcasses and their surrounding environment at various stages along a poultry slaughter line.

Material and methods: Amplicon sequencing of the 16S rRNA gene was employed to assess the shifts in bacterial community diversity at both phylum and genus levels. Samples were collected from September to November 2021, targeting carcass surfaces at various operational stages (post-defeathering, post-evisceration, post-water chilling, and post-cooling), as well as from the internal environments and air of these units. The study took place in a vertically integrated poultry slaughterhouse in Konya, Turkey.

Results: Microbial diversity increased after the chilling and storage stages as a result of redistribution of the microorganisms after the physical effect of the slaughtering stages. The final product sample taken after storage had the highest bacterial abundance. The abundance at this stage was found to be strongly correlated with that at other slaughtering stages, as well as with the abundance in chilling water and on the personnel's hands. The common genera in chicken carcasses during slaughter stages were Macrococcus, Acinetobacter, Enterococcus, Escherichia-Shigella, Psychrobacter, Streptococcus, Lactococcus and Ligilactobacillus. Microbiome data in environmental samples indicated that the genera in highest relative abundance were Bacillus, Anoxybacillus, Acinetobacter and Psychrobacter. In air samples, the storage room had the highest diversity and in this place Bacillus spp. and Staphylococcus spp. were in the majority.

Conclusion: This study may provide some useful information to pinpoint the critical contamination sources in the poultry slaughtering process.

Introduction: Patagonian maras, rodents endemic to South America, are classified as a near-threatened species. Various factors affect their health including parasitic diseases. The aim of this study was to perform morphometric, molecular and phylogenetic characterisation of one such parasitic disease agent, the nematode Graphidioides affinis, specimens of which were found in captive Patagonian maras.

Material and methods: In March 2023, 18 Patagonian maras kept at the Sofia Zoo in Bulgaria were investigated with the use of coprological methods. Following the investigation, the animals were dewormed with the use of albendazole. Dead adult nematodes found in the faeces of dewormed maras were collected and preserved in 70% ethanol, and morphometrically, molecularly and phylogenetically analysed.

Results: The morphometric analyses confirmed the nematodes to be Graphidioides affinis. The partial nucleotide sequences of the small subunit ribosomal rDNA (SSU), the internal transcribe spacer 2 (ITS2) and the large subunit ribosomal DNA (LSU) of G. affinis were obtained. These are the first available nucleotide sequences of this parasite. The phylogenetic analyses of the species showed its distinctiveness in comparison to other gastrointestinal nematodes, as it was grouped separately.

Conclusion: The Patagonian maras kept in a European zoo retained their original parasitofauna which are related to South America.