BMC Veterinary Research最新文献

Background: Aflatoxin B1 (AFB1) contamination in animal feed poses a serious risk to livestock health due to its hepatotoxic effects. Many medicinal herbs which may be used as feed additives exhibit antioxidant and anti-inflammatory properties with potential hepatoprotective outcomes. We investigated effects of AFB1 in three concentrations (30 µg/kg BW, 60 µg/kg BW, 120 µg/kg BW) as well as three medicinal herbs, i.e., kalmegh (Andrographis paniculata), milk thistle (Silybum marianum), and turmeric (Curcuma longa) in pigs. Hepatic expression of genes involved in biotransformation, detoxification, antioxidation, energy homeostasis, and immunity were evaluated by high-throughput real-time PCR.

Results: We found that AFB1 significantly suppressed genes involved in biotransformation (CYP2U1, CYP4V2, CYP7B1, CYP26A1, CYP51A1), detoxification (GSS, ABCC2, SULT1E1), redox balance (GPX1, PRDX4), lipid homeostasis (ACOX1), and immune regulation (CP, CRP). Kalmegh and, to a lesser extent, milk thistle supplementation provided a comprehensive upregulation of genes involved in key hepatic pathways maintaining liver integrity. Under the specific experimental conditions, the applied dietary turmeric supplement did not induce consistent effects on the analyzed target genes.

Conclusions: The results indicate that certain medicinal herbs could counteract AFB1-induced gene expression responses in liver. Their application as dietary supplements to reduce potentially harmful effects caused by AFB1 toxicity in farm animals might be an effective tool in improving animal health, productivity and food safety.

Understanding the physiology and particularities of wild felids is important for improving the ability of veterinary medicine to contribute to the preservation of these species. Thus, the objective of this study was to describe the electrocardiographic parameters and heart rate variability (HRV) of wild jaguars (Panthera onca) captured in Brazil. The anaesthetic protocol used for chemical restraint of the animals involved the drug combination of tiletamine and zolazepam (7 mg/Kg) along with the α2 adrenergic (receptor) agonist dexmedetomidine (10 µg/Kg). The 42 electrocardiographic reports from 39 animals were categorized (sex, estimated age, and body weight) and statistically analysed; 25 females and 14 males between two and 21 years old with a mean weight of 80.96 ± 23 kg were analysed. During the examination, the mean heart rate maintained by the animals was 99 bpm, with a maximum heart rate during the examination of 122 bpm and a minimum heart rate of 93 bpm; the values were comparable with the reference values for large felids. Electrocardiographic parameters differed between the sexes (p < 0,05) (P wave amplitude, QT interval and ST segment) and between the estimated ages (P wave amplitude) and the body weight (P wave amplitude and S amplitude) of the animals. The HRV determined by electrocardiogram did not differ (SDNN 52.89 ± 50.37, rMSSD 59.99 ± 59.79, ApEntropy 0.47 ± 0.36, CVI 3.03 ± 1.35, CSI 1.75 ± 0.82, alpha 1 DFA 0.821 ± 0.264, alpha 2 DFA 0.689 ± 0.385); however, the effect of tiletamine-zolazepam in combination with an anaesthetic agent such as dexmedetomidine (an α2 adrenergic receptor) has never been described. Since this anaesthetic protocol has currently been used effectively in wild felids, the description of electrocardiographic parameters and HRV in free-ranging jaguars seems to be particularly important for future studies of the autonomic tone in the sedation of this species.

Background: Obesity is a well-known concern in pets that often poses challenges in terms of successful maintenance of weight loss after different types of interventions. Nutraceuticals could represent a promising strategy to handle this disease. Among them, Arthrospira platensis (Spirulina) is reported to have beneficial effects in obese dogs, rodents, and humans, possibly due to the richness in several bioactive compounds. In this perspective, omics techniques could be useful tools to unravel both the mechanisms behind obesity, possible unsuccessful clinical outcomes, and the beneficial effects of nutraceuticals. Nevertheless, limited studies evaluating the effects of weight loss programs on obese canine patients, with or without nutraceutical supplementation, using high-throughput transcriptomic analysis, are currently available. In this study, in the context of a twelve-week randomized, double-blinded, controlled dietary trial, twelve healthy overweight neutered female dogs were equally divided into two groups receiving a weight loss diet with (SPI) or without (PLA) the supplementation of Spirulina. In both groups, Retrievers were the most represented breeds. Transcriptomic effects were assessed using RNA-sequencing (RNA-seq) on whole blood samples collected at three different time points, T0 (day 1), T1 (day 42), and T2 (day 84).

Results: According to RNA-seq results, several genes involved in iron transport, homeostasis, and heme biosynthesis were found to be regulated. Moreover, a transcriptional modulation of genes involved in lipid β-oxidation, ferroptosis, and thermogenesis was observed. Most changes were time-dependent, with relatively modest unique effects of Spirulina (only 63 unique differentially expressed genes, DEGs), showing some encouraging outcomes linked to anti-inflammatory and pro-apoptotic pathways.

Conclusions: This study could be considered a starting point to explore the mechanisms behind weight loss and Spirulina supplementation in overweight/obese neutered female dogs. Iron homeostasis is a sort of red thread in our evidence, underlining the importance of the fine-tuning of this micronutrient in obesity. Despite the possible masking effect of the diet, meaningful insights about Spirulina supplementation were disclosed, suggesting its possible beneficial effects. Nevertheless, wider investigations are needed, increasing the number of subjects, comparing other tissues and taking into consideration specific cell populations.

Background: Maintaining immune homeostasis is essential for livestock health and productivity, particularly in the face of infection or stress. Host defense peptides (HDPs), including β-defensins and cathelicidins, are key innate immune components with both antimicrobial and immunomodulatory properties. This study aimed to characterize the immunomodulatory effects of five bovine HDPs-BNBD1, BNBD3, LAP, Bac5, and BMAP27-on peripheral blood mononuclear cells (PBMCs) and bovine turbinate (BT) epithelial cells, under both basal and lipopolysaccharide (LPS)-stimulated inflammatory conditions. Cytokine secretion, cell viability, and real-time epithelial cell behavior were assessed to evaluate peptide-specific immune modulation.

Results: Under non-stimulated conditions, LAP stimulated the secretion of IL-8 (LAP p < 0.0001). In LPS-stimulated PBMCs, prophylactic HDP treatment (4 h pre-LPS) amplified inflammatory cytokine secretion. BNBD3 and LAP significantly increased IL-1β, IL-6, TNF-α, IFN-γ (p < 0.05), and chemokines such as IL-8 and MIP-1α (p < 0.01), suggesting an immune-priming effect that may enhance responsiveness to subsequent LPS stimulation. Notably, BNBD3 and LAP failed to induce a comparable inflammation when added 0.5 h after LPS, highlighting the context-dependent nature of HDP action. Conversely, BMAP27 demonstrated anti-inflammatory activity by reducing LPS-induced IL-1β, IFN-γ, and IL-10 (p < 0.001), irrespective of timing. Bac5 increased IL-8 secretion (p < 0.001) and MCP-1 (p < 0.05), suggesting a chemotactic effect. Cell viability assays confirmed that none of the peptides exhibited cytotoxicity in PBMCs at tested concentrations, although BMAP27 reduced lymphocyte numbers (40% decrease, p < 0.0001), possibly indicating selective immunoregulatory effects. In BT cells, Bac5 enhanced proliferation (11% increase, p < 0.05), while BNBD1 (23% decrease, p < 0.01) and BMAP27 (10% decrease, p < 0.05) mildly reduced cellular impedance, reflecting divergent impacts on epithelial dynamics.

Conclusions: These findings reveal distinct immunomodulatory profiles among bovine HDPs, ranging from pro-inflammatory (BNBD3, LAP) to suppressive (BMAP27), and underscore the importance of treatment timing. The immune-priming capacity of certain HDPs suggests potential use as prophylactic agents to enhance resilience to infections, while suppressive peptides like BMAP27 may serve therapeutic roles in resolving excessive inflammation. Importantly, the variability observed among individual animals emphasizes the need for personalized approaches in immunomodulation. Overall, this study provides novel insights into the immunological functions of bovine HDPs, supporting their potential as alternatives or adjunctive therapies to antibiotics in veterinary medicine.

Background: Mycoplasmopsis (Mycoplasma) bovis is a significant pathogen in North American bison (Bison bison), causing severe disease with high morbidity and mortality. Effective serological diagnostics are essential for the surveillance and management of disease, yet commercially available ELISAs for M. bovis have only been developed for use in cattle and have not been validated in bison. In this study we evaluated a P48-based indirect ELISA for M. bovis detection and compared its diagnostic performance to a commercially available ELISA developed for use in cattle. Serum samples from bison were tested using both assays, and diagnostic metrics were assessed in comparison to infection status as confirmed by PCR and/or culture.

Results: The commercial ELISA demonstrated superior sensitivity (77.8%) and specificity (98.0%) compared to the P48 ELISA (63.9% sensitivity, 94.9% specificity). Combining both ELISAs slightly improved sensitivity (83.3%) but did not significantly enhance overall diagnostic performance. Both the P48 and commercial ELISAs also exhibited cross-reactivity with other Mycoplasma species.

Conclusions: We identify significant challenges in serological diagnostics of M. bovis in bison with implications for interpretation of previous serological studies. Future research should focus on multiple immunogenic targets to enhance sensitivity and specificity for M. bovis serological surveillance.

Background: Mycoplasma gallisepticum (MG) is a major pathogen that causes respiratory diseases 14in poultry, resulting in reduced production and severe economic losses. Current MG detection methods are time-consuming, labor-intensive, and expensive. Hence, the rapid and accurate detection of MG is critical for effective disease control. Therefore, this study aimed to develop a dual-mode diagnostic assay for sensitive and specific detection of MG by combining recombinase-aided amplification (RAA) with CRISPR/Cas12a technology. Conserved regions of the mgc2 gene were used for primer and CRISPR RNA design, and the reaction conditions were optimized to maximize detection efficiency.

Results: The assay achieved a detection limit of 2 copies/µL and demonstrated high specificity against seven other common avian pathogens. Detection was visualized within 1 h using either fluorescence or lateral flow dipstick. Moreover, clinical validation of chicken samples showed complete concordance with quantitative real-time polymerase chain reaction results. Furthermore, an epidemiological investigation revealed that chickens had the highest positivity rate for MG among chickens, ducks, and pigeons in Hubei Province.

Conclusions: This simple, rapid, field-deployable method is valuable for timely MG surveillance and effective disease management in poultry production.