Veterinary Research Communications最新文献

Background: Inclusion body hepatitis (IBH) and Newcastle disease (ND) impose substantial economic burdens on global poultry production, with combined annual losses exceeding $3 billion worldwide. Current vaccination strategies requiring separate immunizations increase handling stress and operational costs.

Objective: To evaluate immunogenicity, cross-neutralization patterns, protective efficacy against virulent challenge, maternal antibody transfer, and commercial field performance of a novel multivalent inactivated vaccine containing fowl adenovirus (FAdV) serotypes 2, 8a, 8b, and 11 combined with Newcastle disease virus (NDV).

Methods: Two randomized, blinded, placebo-controlled trials were conducted: SPF trial (n = 200, Egypt) and commercial field trial (n = 120,000, Saudi Arabia). The multivalent vaccine contained inactivated FAdV serotypes 2, 8a, 8b, and 11 plus NDV strains, administered at 10 and 16 weeks of age with 24-week monitoring.

Results: Vaccination induced robust antibody responses with FAdV ELISA geometric mean titers (GMT) reaching 22,847 (95% CI: 18,245 - 28,589) at weeks 4-6 post-primary vaccination, with peak anamnestic response of 28,945 (95% CI: 23,186 - 36,115) at week 8 following booster (p < 0.001) and NDV hemagglutination inhibition titers of 9.8 log₂ (95% CI: 8.4-11.4) (p < 0.001). Challenge studies demonstrated 96.7% protection against FAdV-2 (species D) (29/30 vaccinated vs. 6/30 controls; Fisher's exact p < 0.0001) and 100% protection against NDV (30/30 vs. 0/30). Maternal antibody transfer efficiency was 68.6% for IBH and 81.7% for NDV, with half-lives of 4.2 and 4.8 days respectively, providing 24-28 days and 21-24 days protection in progeny. Commercial field trial (120,000 birds) demonstrated 94.2% reduction in IBH mortality with 3.47:1 return on investment.

Conclusions: The multivalent IBH-NDV vaccine provides comprehensive immunological protection and consistent field efficacy. Although the cross-neutralization assay included representative serotypes, broader testing across additional field isolates is warranted to further define cross-protective breadth. Cross-neutralization analysis confirms the necessity of multivalent formulations due to type-specific immunity patterns, supporting implementation for integrated disease control in commercial broiler operations. This study provides a detailed evaluation of a quadrivalent FAdV-NDV inactivated vaccine demonstrating efficient maternal antibody transfer in broiler breeders.

This review critically evaluates recent advances in understanding the adverse effects of thermal pollution on rainbow trout (Oncorhynchus mykiss), focusing on the integrated roles of heat shock proteins (HSPs) and acute-phase proteins (APPs) in stress adaptation. The primary objective is to clarify mechanistic pathways through which temperature elevation and fluctuations, often driven by anthropogenic activities, disrupt homeostasis and trigger molecular and systemic stress responses in this cold-water species. The review synthesizes experimental and field findings to outline how distinct thermal stressors influence the expression, induction and functional modulation of HSPs and APPs, which act as biomarkers and mediators of resilience through protein folding, oxidative balance, immune signaling and survival mechanisms. Major topics include: (i) characterization of HSP families (e.g., HSP70, HSP90) in thermal responses; (ii) APP-mediated inflammation and immune modulation and (iii) molecular networks linking heat shock signaling to physiological outcomes such as altered growth and reproduction. Although considerable progress has been made, variability across study conditions restricts generalization. Future research should focus on (i) defining the specific functional roles and cross-talk of small HSPs (sHSPs) under chronic stress, (ii) investigating epigenetic mechanisms underlying intergenerational thermotolerance and (iii) applying integrated multi-omics approaches to map regulatory interactions between HSPs, APPs and overall stress physiology under climate-driven warming. These efforts will guide strategies to strengthen thermal resilience and welfare in aquaculture and conservation.

Weaning is a critical stage in swine production, characterized by intestinal alterations that affect piglet health and performance. In this study, machine learning techniques were applied to identify joint patterns between gut health and productivity during the first 15 days post-weaning. A total of 103 animals were analyzed using a dataset of 24 histomorphological, biochemical, and productive variables. Among the unsupervised clustering models, K-means (k = 2) achieved the best separation, revealing two groups with significant differences in intestinal parameters (villus height-to-crypt depth ratio, intestinal absorptive area, duodenal maltase activity, butyric, propionic and total volatile fatty acid concentrations) and performance outcomes (body weight at 15 days and average daily gain). Supervised models were subsequently applied as interpretative tools to assess variable relevance, with Random Forest achieving high internal consistency. SHAP analysis indicated that intestinal morphology, enzymatic activity, and microbial metabolites (particularly total volatile fatty acids, propionate, and butyrate) were most strongly associated with cluster classification. These findings highlight coordinated patterns between intestinal function and growth during the early post-weaning period and suggest that such biomarkers may represent potential targets to be explored in future nutritional strategies. Overall, this study demonstrates the potential of integrating unsupervised explainable machine learning approaches into animal science research for exploratory analysis and hypothesis generation.

Paslahepevirus balayani (Hepatitis E virus, HEV) is an emerging zoonotic pathogen with a wide host range, yet its circulation in African equids remains poorly understood. This study provides the first serological investigation of HEV in donkeys in Algeria, aiming to assess exposure levels and identify potential infection-related risk factors. Between 2019 and 2024, 183 donkeys were sampled across three northeastern provinces (Mila, Souk-Ahras, and Tébessa), representing diverse agroecological conditions and including both working donkeys and animals used in cross-border smuggling. Individual data on age, sex, health status, body condition, movement history, and season were recorded. Sera were screened using a proprietary recombinant antigen, which is highly conserved across different HEV strains. All samples tested negative for anti-HEV antibodies. The sample size exceeded the minimum required to detect the highest seroprevalence previously reported in donkeys (12.22%), supporting the epidemiological significance of the negative findings. The absence of seropositivity may reflect limited regional exposure to known HEV reservoirs, local husbandry practices, and environmental conditions that reduce infection risk. These results suggest that HEV is currently not circulating at detectable levels in donkeys from northeastern Algeria. Broader studies, including molecular approaches and additional species, are recommended to clarify HEV ecology in the region.

Infectious myonecrosis virus (IMNV) is considered one of the pathogens that most affect the production of Penaeus vannamei, causing economic losses estimated at billions of dollars. P. vannamei rearing is expanding to inland waters, which are commonly used for the farming of Macrobrachium rosenbergii, increasing the probability of exposure of this freshwater prawn to viruses often reported in penaeids, including IMNV. Therefore, the aim of the present study was to investigate the susceptibility of M. rosenbergii to IMNV through an intramuscular challenge. M. rosenbergii subadults and adults were inoculated intramuscularly with IMNV obtained from the abdominal muscle tissue of naturally infected P. vannamei. The viral challenge lasted 21 days. All samples had positive nested-PCR results as well as clinical signs and histopathological findings typical of the virus, such as hemocyte infiltration and muscle sinus dilation. This is the first study to demonstrate the susceptibility of M. rosenbergii subadults and adults to IMNV. Although no massive mortalities were detected in the challenged prawns, the presence of M. rosenbergii as a viral source in the cultivation environment should not be underestimated.