Diversity and Reassortment Rate of Influenza A Viruses in Wild Ducks and Gulls

Influenza A viruses (IAVs) evolve via point mutations and reassortment of viral gene segments. The patterns of reassortment in different host species differ considerably. We investigated the genetic diversity of IAVs in wild ducks and compared it with the viral diversity in gulls. The complete genomes of 38 IAVs of H1N1, H1N2, H3N1, H3N2, H3N6, H3N8, H4N6, H5N3, H6N2, H11N6, and H11N9 subtypes isolated from wild mallard ducks and gulls resting in a city pond in Moscow, Russia were sequenced. The analysis of phylogenetic trees showed that stable viral genotypes do not persist from year to year in ducks owing to frequent gene reassortment. For comparison, similar analyses were carried out using sequences of IAVs isolated in the same period from ducks and gulls in The Netherlands. Our results revealed a significant difference in diversity and rates of reassortment of IAVs in ducks and gulls.

Carcass, physicochemical and sensory characteristics of meat from genetic reserve ducks after two reproductive seasons

The aim of the study was to compare carcass composition and meat quality of i) Pekin ducks of French origin (P9), ii) crosses of wild mallard and Pekin duck (K2), and iii) crosses of Khaki Campbell drakes and Orpington Fauve ducks (KhO1). Twenty carcasses from 110-week-old ducks of each genetic group were used. Carcass weight of P9 was significantly higher than that of K2 and KhO1. Carcasses of K2 ducks had a significantly lower percentage of neck and leg muscles and giblet weight compared with P9 and KhO1 ducks, while carcasses of KhO1 ducks had a significantly higher percentage of wing meat compared with K2 and P9, and a significantly lower percentage of breast muscles compared with P9 ducks. Breast and leg muscles of P9 contained significantly more water than those of K2 and KhO1, and the breast muscles of P9 ducks had more protein and less fat than those of KhO1 birds. The leg muscles of KhO1 contained significantly more protein, and those of K2 had significantly more fat than the other duck groups. Breast muscles of P9 and KhO1 ducks had significantly more collagen but had less in leg muscles compared with K2. Breast fillets from P9 ducks showed higher L*, a*, and b* colour values and shear force than K2 and KhO1 ducks. Keywords: carcass composition, conservation flocks, meat quality, spent duck

Influenza A virus prevalence and its implications on survival in mallard

Avian influenza is an infectious viral disease of birds caused by type A strains of the influenza virus. Aquatic bird species have adapted to carry and transmit a wide range of influenza strains in nature. Here we report the results of a 4.5-year monitoring program forOrthomyxovirusprevalence in a population of wild mallard (Anas plathyrynchos) in northwestern Italy. To determine whetherOrthomyxovirusprevalence affects survival, we used MARK software to compare the survival of AIV-positive versus AIV-negative birds. Prevalence rates and variance were estimated using inverse sampling method. The prevalence rate of influenza A virus was 4.3% (SE 0.00116) and lifespan was shorter (29.8%) for the young infected birds than for the young non-infected birds.