Avian Metapneumovirus (aMPV) has been recognized as a respiratory pathogen of turkey and chickens for a long time. Recently, a crescent awareness of aMPV, especially subtype B, clinical and economic impact has risen among European researchers and veterinarians. Nevertheless, the knowledge of its epidemiology and evolution is still limited. In the present study, the broadest available collection of partial G gene sequences obtained from European aMPV-B strains was analyzed using different phylodynamic and biostatistical approaches to reconstruct the viral spreading over time and the role of different hosts on its evolution. After aMPV-B introduction, approximatively in 1985 in France, the infection spread was relatively quick, involving the Western and Mediterranean Europe until the end of the 1990s, and then spreading westwards at the beginning of the new millennium, in parallel with an increase of viral population size. In the following period, a wider mixing among aMPV-B strains detected in eastern and western countries could be observed. Most of the within-country genetic heterogeneity was ascribable to single or few introduction events, followed by local circulation. This, combined with the high evolutionary rate herein demonstrated, led to the establishment of genetically and phenotypically different clusters among countries, which could affect the efficacy of natural or vaccine-induced immunity and should be accounted for when planning control measure implementation. On the contrary, while a significant strain exchange was proven among turkey, guinea fowl and chicken, no evidence of differential selective pressures or specific amino-acid mutations was observed, suggesting that no host adaptation is occurring.

nomic losses mainly due to respiratory or reproductive problems (Cecchinato et al., 2012), often exacerbated by secondary bacterial infections (Giovanardi et al., 2014).First, aMPV isolations in Europe date back to the second half of the 1980s, when turkey rhinotracheitis (TRT) outbreaks appeared in

This study was conducted to evaluate the safety and the beneficial effects of dietary supplementation with Boswellia serrata (Bs) and Salix alba (Sa) in Leghorn hens during the critical pre-laying and laying phases. A total of 120 pullets, 17 weeks of age, were assigned to two groups (Control—C; Treated—T, n = 60 each). For 12 weeks, the T group received a diet supplemented with 0.3% of dry extracts of Bs (5%) and Sa (5%). The study lasted 19 weeks. Productive performance, serum analytes, H/L ratio, IgA and anti-IBV antibodies were investigated. Water intake was significantly higher, while body and egg weight was significantly lower for the T group (p < 0.05). No other differences were detected in performance parameters, serum analytes, IgA and H/L ratio excluding t0, with a significantly (p < 0.05) higher H/R ratio and higher titers of anti-IBV antibody for the T group. Overall, the data obtained in this study show that the supplementation with Bs and Sa was safe and resulted in an increase in water consumption, a decrease in egg weight, and a sedative effect in the hens. In the future, it would be interesting to test this supplement in hens reared on intensive farms.

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Recent insights into the genetic and antigenic variability of avian metapneumovirus (aMPV), including the discovery of two new subtypes, have renewed interest in this virus. aMPV causes a well-known respiratory disease in poultry. Domestic species show different susceptibility to aMPV subtypes, whereas sporadic detections in wild birds have revealed links between epidemiology and migration routes. To explore the epidemiology of aMPV in wild species, a molecular survey was conducted on samples that were collected from wild birds during avian influenza surveillance activity in Italy. The samples were screened in pools by multiplex real time RT-PCR assays in order to detect and differentiate subtypes A, B, C, and those that have been newly identified. All the birds were negative, except for a mallard (Anas platyrhynchos) that was positive for aMPV subtype C (sampled in Padua, in the Veneto region, in 2018). The sequencing of partial M and full G genes placed the strain in an intermediate position between European and Chinese clusters. The absence of subtypes A and B supports the negligible role of wild birds, whereas subtype C detection follows previous serological and molecular identifications in Italy. Subtype C circulation in domestic and wild populations emphasizes the importance of molecular test development and adoption to allow the prompt detection of this likely emerging subtype.