Restrictions on the use of antimicrobial compounds have led to a surge of interest in alternative solutions, such as natural, plant-based compounds. In our study, we investigated the efficacy of three feed supplements containing different additives, namely, probiotics (Lactobacillus spp., “Test substance A”), turmeric (Curcuma longa L., “Test substance B”), and fenugreek (Trigonella foenum graecum, “Test substance C”). In the experiment, we tested 180 birds of the Bábolna Tetra-SL laying hybrid breed that were infected with Salmonella enteritidis strains. The birds were randomly divided into six groups: three groups treated with the different additives, a negative control group, a positive control group, and an antibiotic-treated group using enrofloxacin. We examined the maturation and the time course of shedding of Salmonella; at the end of rearing, pathological and histopathological examinations were performed. When Salmonella was isolated from the cloacal swab samples, the enrofloxacin-treated group had a high number of animals shedding Salmonella by day 9, which was like the group treated with test material C. The greatest reduction in Salmonella shedding was observed in the groups treated with test materials A and B. In terms of pathological parameters, villus length and crypt depth were significantly better in the group treated with test material C compared to the positive and negative controls, and when comparing the body weight of the tested animals, the group treated with test material B had a significantly larger absorption surface area compared to the positive control group. Overall, the supplement with test material C proved to be the most effective. In the future, it is worthwhile to investigate the combination of the tested active substances for their possible synergistic effects and to perform a dose-response study to select the optimal dosage.

Background: Avian influenza (AI), caused by orthomyxoviruses, is a globally significant disease affecting avian and non-avian species. It manifests in two variants, according to the two biovariants of the virus differentiated as highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) strains, both of which compromise animal welfare, reduce productivity, and cause substantial economic loss. The zoonotic potential of HPAI strains, particularly the currently dominant clade 2.3.4.4b, raises concerns about public health and epidemic risks. This review assesses the results of current vaccine trials targeting HPAI clade 2.3.4.4b, emphasizing these studies because most outbreak strains in domestic poultry currently belong to this dominant clade. Methods: Multiple scientific databases comprised reports of research trials on vaccine efficacy against HPAI clade 2.3.4.4b. The Boolean term “Clade 2.3.4.4b AND vaccine” was entered into the following databases: PubMed, PubAg, Scopus, Cochrane Library, and ScienceDirect. Results: The resulting papers were analyzed. Studies revealed that antigenic similarity between vaccine and field strains enhances protective efficacy (PE), reduces viral shedding, and improves hemagglutination inhibition titers. While multivalent vaccines showed potential, results were inconsistent and varied depending on strain compatibility. Single-dose vaccines may provide sufficient PE for poultry, though ducks and geese often require multiple doses, and long-term PE is yet unknown. It was discovered that vector vaccines can provide appropriate PE against clade 2.3.4.4.b. Conclusions: Further analysis is needed as their effects may be short-lived, and subsequent doses may be required. Limited research exists on the long-term efficacy of these vaccines and their effectiveness in many avian species. Addressing these gaps is crucial for optimizing vaccination strategies. A re-evaluation of vaccination strategies is recommended but essential to implement adequate biosecurity measures on in poultry farms. This review synthesizes current evidence and may assist veterinarians and authorities in deciding whether to apply or license vaccines to reduce economic losses caused by AI.

Necrotic enteritis, caused by Clostridium perfringens (C. perfringens) is a disease present worldwide and causes major economic losses. The re-emergence of the disease, in recent years, is mainly due to the ban of the usage of antibiotics as growth promoters in the EU. The aim of this study was to establish a reliable, robust challenge model. Ross hybrid broilers were divided into randomized groups: a positive and a negative control group, a group receiving antibiotic treatment and three groups fed with assorted feed supplements, all receiving the same basal diet. The birds in the treatment groups were vaccinated twice using a 10-times dose of an Infectious Bursitis live vaccine and the animals were challenged four times with a NetB toxin producing C. perfringens strain. The presence of clinical signs and body weight gain were monitored. At the end of the study necropsy was performed and the gut lesions were scored. During the experiment, clinical signs were absent in the negative control group and in the antibiotic treated group. The other animals displayed diarrhea and feather loss. These symptoms were the most pronounced in the positive control group. The gut lesion scores showed significant differences between the negative and positive control groups, with the former scoring the lowest. Based on these results, the challenge model establishment was successful and in this setup the assessment of the potency of feed additives is also possible.

A szerzők hazánkban elsőként diagnosztizáltak Chicken Proventricular Necrosis Virus (CPNV) okozta félheveny, elhalásos mirigyesgyomor-gyulladást növendék fácánban (Phasianus colchicus). A 3–4 hetes életkorú fácáncsibékben szétnövés, kiegyenlítetlen fejlődés mellett a mirigyesgyomor interglandularis régióinak lympho-histiocytás beszűrődését, ill. a mirigyhámsejtek solitaer ill. multiplex, gócos degenerációját/elhalását figyelték meg. A munka során a kimutatott vírusgenom szekvenciájának meghatározásával és annak elemzésével azonosították az átoltható, vírusos mirigyesgyomor-gyulladást (Chicken Proventricular Necrosis Virus, CPNV) örökítő anyagát.

Transmissible viral proventriculitis (TVP) is an emerging disease in chickens, linked to chicken proventricular necrosis virus (CPNV), a recently identified birnavirus. Here, we describe the first molecular-confirmed case of TVP in Bangladesh, affecting both a white layer flock and a coloured meat-type parent stock (PS). Affected birds exhibited growth retardation, diarrhoea, and increased mortality, alongside hallmark gross changes of proventricular enlargement and wall thickening. From the meat-type PS, proventricular samples were collected for histopathology and molecular diagnostics. Histological analysis revealed severe glandular epithelial damage, necrosis, mononuclear infiltration, epithelial hyperplasia, and metaplasia. Using RT-PCR on nucleic acid extracted from FTA card samples, we detected CPNV, in addition to infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), and avian reovirus (ARV). The amplified CPNV VP1 fragment was sequenced, and phylogenetic analysis placed the Bangladeshi strain within clades of previously reported CPNV isolates. This study represents the first report of CPNV and TVP in Bangladesh, highlighting the need for active surveillance in commercial and breeder poultry flocks to understand the virus’s epidemiology and support the development of control strategies.

Background: Bacteriophage-based interventions are increasingly considered antibiotic-sparing tools in poultry production, but target-animal tolerability should be documented before efficacy-oriented field application. Methods: This pilot study evaluated the formulation-level tolerability of the repeated drinking-water administration of Fagovet, a commercial multi-component bacteriophage product, in Ross 308 broiler chickens under non-challenged conditions. According to the manufacturer’s product documentation, the formulation contains a declared mixture of 23 bacteriophages at a concentration of not less than 1 × 10⁶ plaque-forming units per milliliter. However, the concentration of active bacteriophages was not independently confirmed immediately before administration or after dilution in drinking water. A total of 120 birds were allocated to 12 pens, with three replicate pens per treatment, and received untreated water or product-volume-based administration rates corresponding to 1×, 3×, or 5× the manufacturer-recommended rate for 27 days. Body-weight gain and pen-level feed intake were analyzed using linear mixed-effects models with Dunnett-adjusted comparisons against controls. Clinical observations, mortality, diagnostic necropsies, terminal gross postmortem examination of all surviving birds, and descriptive histopathology in eight randomly selected birds, comprising two birds per treatment group, were used as supportive endpoints. Results: Body-weight gain did not differ from controls at 1× (ratio 0.99; 95% CI 0.88–1.10; p = 0.9856), 3× (1.03; 0.92–1.15; p = 0.8273), or 5× (1.01; 0.91–1.13; p = 0.9902). Feed intake showed no significant treatment-related reduction, and no consistent dose-related adverse clinical or pathological pattern was identified. Conclusions: Repeated drinking-water administration of the tested commercial formulation was well tolerated under the conditions of this pilot study. Because individual phage components, genomic safety, actual PFU-based exposure, and drinking-water stability were not independently characterized, the findings apply to the administered formulation and should not be interpreted as a component-level safety or quantitative phage dose–response assessment.