Journal of Veterinary Research最新文献

Introduction: Lactococcus garvieae is a catalase-negative, Gram-positive coccus that occurs in pairs and short chains. It is present throughout the world and a causative agent of bovine mastitis. However, prior to writing, no case of mastitis caused by this bacterium had been reported in Poland. The aim of this research was to investigate the presence of L. garvieae in milk samples from Polish cows with inflammation of the mammary gland.

Material and methods: A total of 118 milk samples from 96 Holstein-Friesian cows were spread on blood agar plates for microbial analyses. Then analysis with matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometry, biochemical identification and antibiotic susceptibility evaluation in the VITEK 2 system and a PCR with primers compatible with 16S ribosomal RNA of L. garvieae were performed.

Results: The presence of three strains of L. garvieae was confirmed in milk samples. Analysis of antibiotic susceptibility showed the susceptibility of all isolates to moxifloxacin, erythromycin, linezolid, teicoplanin, vancomycin, tetracycline, tigecycline, chloramphenicol and trimethoprim-sulfamethoxazole. Lactococcus garvieae had high resistance to benzylpenicillin, clindamycin and rifampicin. One of the isolated strains was additionally resistant to tetracycline and had different minimum inhibitory concentrations.

Conclusion: To the best of our knowledge, L. garvieae had not been identified as an aetiological factor of mastitis in cows in Poland before, and the presented research is the first report.

The aim of this article was to review current knowledge of the anatomy and physiology of the avian eye and ocular diseases in poultry. The avian visual organ consists of the eye and extraocular organs and, unlike the mammalian eye, is characterised by many structural and functional adaptations that enhance vision. Avian eyes do not have the same functions as mammalian eyes. Bird eyes have high sensory sensitivity and are capable of constellation recognition for star orientation and navigation; they may be regarded as the finest ocular organs in the animal kingdom. It is generally accepted that the considerable differences in the morphology and function of avian eyes are largely due to adaptations to specific activities and environmental conditions. Eye diseases are rarely diagnosed in poultry because, unlike livestock and pets, detailed ophthalmological examinations are not carried out on farmed birds. Nevertheless, poultry are frequently affected by ocular pathologies, including developmental abnormalities, infectious and non-infectious diseases, degenerative processes, tumours, injuries and pathological conditions of unknown aetiology. In poultry, ocular disease is often associated with respiratory and systemic disease. Ocular pathology in farmed birds has a complex aetiology and its incidence can be reduced by controlling the incubation parameters of hatching eggs, avoiding feeding errors in breeder flocks and rearing poultry under conditions that optimise welfare and comply with biosecurity standards.

Introduction: This study investigated the impact of adding crude fibre concentrate (CFC) to broiler chicken diets on slaughter results and breast muscle quality.

Material and methods: A total of 990 male Ross 308 chicks were divided into control (C), experimental 1 (A1) and experimental 2 (A2) groups. Experimental diets contained CFC at different levels: A1 had 0.4% in the starter diet, 0.8% in the first grower diet, 0.8% in the second grower diet and 0.2% in the finisher diet, and A2 had 0.6%, 1.0%, 1.2% and 0.4% in the same diets. On day 42, 20 birds per group were slaughtered and dissected. Breast muscles were weighed and visually assessed for myopathic defects (white striping, wooden breast and "spaghetti" meat). The tissue was also analysed for residual myopathy incidence and associated physicochemical properties, namely drip loss, shear force, pH, water holding capacity, collagen content, colour parameters and basal chemical composition.

Results: Consumption of the CFC additive statistically significantly reduced (P-value ≤ 0.05) white striping defects and increased final live weight by 2.1% for birds in group A1 and by 3.3% in group A2. Group A1 carcasses also weighed 6.7% more and group A2 carcasses 4.1% more. Additionally, A1 carcasses yielded 1.5% more and A2 carcasses 0.8% more leg muscle, also statistically significantly greater yields than C carcasses (P-value ≤ 0.05). The slaughter yield of birds in group A1 was 3.3% higher (P-value ≤ 0.001) than that of birds in group C. The use of the CFC additive in the diets of both experimental groups had no adverse effect on the other analysed parameters.

Conclusion: Crude fibre concentrate addition to the complete feed mixture is recommended for improving the results of the slaughter analysis and the visual quality of meat.

Introduction: Aujeszky's disease is caused by suid herpesvirus-1, also called Aujeszky's disease virus (ADV). The main reservoir host is the wild boar (Sus scrofa). The last data about ADV seroprevalence in wild boar in Poland came from over 10 years ago. There is a gap in knowledge about the current epidemiological situation. Therefore, this study aimed to characterise ADV seroprevalence and risk factors in hunted wild boar in south and central Poland.

Material and methods: Between February and June 2024, blood samples were collected from 320 wild boar (143 females and 177 males). Total antibodies to ADV were detected by a commercial indirect ELISA kit. The results were statistically analysed.

Results: Antibodies against ADV were detected in serum samples from 103/320 animals (32.19%). The wild boars were more likely to be ADV seropositive with age, but the uncertainty of this prediction increased with age. Sex and location of animals did not influence ADV seroprevalence.

Conclusion: The study revealed that the wild boar is still an important ADV reservoir in Poland. Even though Poland has ADV-free status, the results indicate that the situation in wild boar should be monitored. There is the risk of spillover of ADV from wild boar to domestic pig herds, potentially interfering with the control programme in Poland. The ADV seroprevalence in wild boar population shows not only a risk of the virus' reintroduction into pig herds but also a potential threat to other domestic and wild mammals.

Introduction: The transport of Newcastle disease virus (NDV) specimens, isolates or purified RNA is traditionally performed at ultra-low temperatures using dry ice to prevent degradation. However, this method is costly and requires specialised packaging and stringent shipping conditions. The aim of this study is to evaluate existing products' capacities to preserve NDV or its RNA under different conditions.

Material and methods: Flinders Technology Associates (FTA) cards, RNASound cards, and RNAstable tubes were tested for their ability to preserve NDV RNA at ambient temperatures. Two controls - free RNA and free virus - were included for comparison. Preservation was evaluated at various storage conditions (-80°C, -20°C, 4°C, 25°C and 56°C) and incubation times (1, 7, 14, 28 and 35 d) using a reverse-transcription PCR, Sanger sequencing and ratiometric fluorometry.

Results: All preservation methods performed effectively at lower temperatures. The FTA cards maintained consistent RNA integrity with Δ threshold cycles < 2 except at 56°C on days 14-35. RNASound preserved RNA stably but was inconsistent on day 35 at 56°C. RNAstable was effective at intermediate times but had allowed complete degradation by day 35. Free RNA degraded rapidly after day 1, while free virus initially remained stable but deteriorated over time. Sanger sequencing confirmed high-quality recovery, except for recovery of free RNA, which lacked long-term stability.

Conclusion: Despite challenges with prolonged storage and high temperatures, these methods demonstrated satisfactory performance. They offer viable alternatives to ultra-low temperature storage, enabling sample transport at ambient temperatures while preserving RNA integrity, and could be particularly useful in remote settings.

Introduction: The cellular and molecular pathways of α-lipoic acid's (ALA's) protective effect were assessed against diclofenac (DIC) hepatorenal injury in vivo and against a pro-inflammatory stimulus in vitro.

Material and methods: The injury was induced in 28 adult male Wistar rats weighing 130-160 g by a single intraperitoneal injection of DIC (50 mg per kg body weight (b.w.)) on the fifth day. Seven positive control rats had received no hepatorenally protective compounds. Oral 100 mg/kg b.w. doses of silymarin (SLY) were given to seven animals, 50 mg/kg b.w. doses of ALA to seven more and 100 mg/kg b.w. doses of it to another seven for five days before DIC insult. Seven negative control rats received only distilled water instead of protective compound and in the injection. The anti-inflammatory effect of ALA was also assayed in murine RAW264.7 macrophage cells.

Results: In the cells, ALA was antioxidant and anti-inflammatory in a dose-dependent manner, reducing nitric oxide (NO) and reactive oxygen species generation with half maximal concentrations of 7.8 and 6.25 μg/mL, respectively. Both ALA doses and SLY protected the hepatorenal tissues and improved kidney and hepatic functions compared to the organs of the positive control group. Additionally, ALA reduced oxidative stress biomarker levels in hepatic and renal tissues compared to the positive control rats. It also improved liver and kidney histology, where hepatic lesions were fewer, and protected renal architecture. Immunohistochemical analysis showed ALA to reduce caspase-3 expression, supporting its hepatorenal anti-apoptotic effect. Alpha lipoic acid markedly upregulated the hepatorenal messenger RNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), haem oxygenase-1 and nicotinamide adenine (phosphate) reduced form : quinone oxidoreductase 1, suggesting that the Nrf2 signalling pathway was enhanced.

Conclusion: These findings suggested potential therapeutic benefits for ALA in mitigating DIC-induced hepatorenal toxicity through its anti-inflammatory, antioxidant and Nrf2-mediating effects. Future investigations are warranted to explore the synergistic interactions and multiomics mechanisms.

Introduction: In Germany, around 150,000 kg of mostly Siberian sturgeon (Acipenser baerii), were produced in 2021. Sudden mortalities affected negative control Russian sturgeon in experimental infection of several European aquacultured fish species with tilapia lake virus (TiLV). An investigation sought the causative agent. In most of the sturgeon, a specific herpesvirus was detected which also occurred in the carp, crucian carp and tench subjects, but not in Nile tilapia. This herpesvirus was latent in the sturgeon population but became productive to cause the outbreak after three weeks of experimentation.

Material and methods: Different European aquacultured fishes were experimented upon. Chosen PCRs, nested PCRs and re-amplifications were carried out to identify the causative agent of the mortality event. Sequence analysis of the obtained PCR fragment and in-situ hybridisation (ISH) using tissue sections of the experimental fishes were performed.

Results: The PCRs used for detection of Acipenser herpesvirus (AciHV)-1 and -2 were always negative. An additional PCR assay with lesser specificity for AciHV found 118 of 123 sturgeon samples and some samples of cohabited cyprinids positive. The similarity of all isolates was 99.7%. The PCR results were confirmed by ISH using probes based on the same sequence, which detected identical viral sequences in both sturgeon and cyprinid samples. These findings revealed that a sterlet sequence previously deposited in the NCBI database had been incorrectly classified.

Conclusion: It seems that different herpesviruses and/or a new subspecies of AciHV are widespread in European farmed sturgeon populations, which, at least for aquacultured fish, opens up the possibility of vaccination against the disease which they cause. Additionally, a more specific diagnostic PCR has to be established.

Introduction: Over the past three decades, emerging epidemiological evidence has shown the increasing incidence and prevalence of nontuberculous mycobacteria (NTM). As a result, clinical awareness of the impact these organisms have on both human and animal health has grown.

Material and methods: Two captive black howler monkeys (Alouatta caraya) were experiencing recurrent diarrhoea. Their faecal samples were processed by suspension, decontamination and culture to propagate Mycobacterium. Immunochromatography and molecular studies were undertaken to detect parasites. The antimicrobial susceptibility of bacterial isolates was tested using broth microdilution. Additionally, mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) typing was performed to assess the Mycobacterium pattern.

Results: Mycobacterium avium subsp. hominissuis was identified and noted to have a novel MIRU-VNTR pattern (22221229). No parasites were detected by immunochromatography, but Giardia intestinalis was identified by PCR. This marks the first documented case of co-infection with Mycobacterium avium subsp. hominissuis and Giardia intestinalis in a black howler monkey.

Conclusion: Collecting clinical isolates from infected animals is vital for comparing them with other isolates, including those from the environment, and for re-evaluating their potential as pathogens. Our study is significant within the context of veterinary disease control and the One Health approach.

Introduction: Neurokinin B (NKB), dynorphin A (Dyn A) and kisspeptin (KiSS) are key agents that participate in the neuroendocrine regulation of the development and functioning of the reproductive system. While the role of KiSS is better understood, the functions of NKB and Dyn A at the pituitary level have not been elucidated. The objective of our study was to analyse their direct effect on kisspeptin-10 (KiSS-10) secretion by anterior pituitary cells isolated from pubescent ewes.

Material and methods: Pituitary cells from 10-month-old ewe lambs were incubated in McCoy's 5A medium without hormones (the control), or with 10^-11, 10^-10, 10^-9, 10^-8 or 10^-7 M of NKB or Dyn A for 2, 4, 6, 12, 18 or 24 h. The concentration of KiSS-10 was analysed by ELISA using species-specific antibodies.

Results: When applied at the concentrations of 10^-10-10^-7 M, NKB increased KiSS-10 secretion throughout the entire experiment (2-24 h), compared to the control. Significantly higher (P-value ≤ 0.05) KiSS-10 release than in the control was observed after 6-24 h exposure of the cells to 10^-8 M of NKB. However, no effect of NKB on the secretion of KiSS-10 was shown when applied at the lowest concentration (10^-11 M). In turn, there was no significant effect of Dyn A at any concentration on KiSS-10 secretion by pituitary cells at any time.

Conclusion: In contrast to Dyn A, NKB can directly affect KiSS-10 secretion from the pituitary cells of pubescent ewes in a way dependent on the time of exposure to this neuropeptide and its concentration in the culture medium. This phenomenon may indicate a potential role of NKB in the initiation of reproductive activity, which leads to the achievement of sexual maturity in the optimal developmental window.

Introduction: The global swine industry faces significant challenges related to improving the survival and health of newborn piglets. Attention has come to β-hydroxy-β-methylbutyrate (HMB), a metabolite of leucine, for its potential in prenatal nutritional programming in sows, which can improve piglet body weight and support the development of the skeletal and digestive systems. The effects of prenatal HMB supplementation were investigated on the chemical coding of the enteric nervous system (ENS) in the small intestine of neonatal piglets.

Material and methods: The experiment was conducted on piglets from 12 sows divided into a control and an experimental group. Sows in the experimental group received HMB at a dose of 0.2 g/kg body weight per day from day 70 to 90 of gestation. After parturition, one piglet from each litter was euthanised and parts of the duodenum, jejunum and ileum were exsected. Tissue sections were fixed in paraffin, reacted with anti-vasoactive intestinal peptide (VIP), anti-cocaine- and-amphetamine-regulated transcript (CART), anti-neuronal nitric oxide synthase (nNOS) and anti-substance P (SP) antibodies, and the immunoexpression of VIP, CART, nNOS and SP was determined histomorphometrically by calculating the area of fibres which were immunoreactive with each.

Results: Supplementation with HMB in sows caused significant changes in the ENS of newborn piglets, including an increase in the area of fibres reactive to CART and nNOS in certain layers and sections of the small intestine, and a decrease in the area of fibres reactive to SP and VIP.

Conclusion: The results indicate that prenatal supplementation with HMB in sows may significantly influence the functioning of the gastrointestinal tract in newborn piglets.