Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recom...Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.展开更多
Background: The present work is aimed at evaluating the effect of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens,L.;HI) larva meal for ducks.A total of 192 female 3-day-old Musc...Background: The present work is aimed at evaluating the effect of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens,L.;HI) larva meal for ducks.A total of 192 female 3-day-old Muscovy ducklings(Cairina moschata domestica,Canedins R71 L White,Grimaud Freres Selection,France) were divided into 4 groups,assigned 4 different dietary treatments(6 replicates/treatment and 8 birds/replicate) and reared from 3 to 50 days of age.HI larva meal was included at increasing levels(0,3%,6% and 9%,HI0,HI3,HI6 and HI9,respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter(3–17 days of age),grower(18–38 days of age) and finisher(39–50 days of age).The growth performance and apparent total tract digestibility were evaluated during the trial using titanium dioxide as an inert marker(0.3% of inclusion).At 51 days of age,two birds per pen were slaughtered and histomorphological investigations were performed.Results: The live weight and average daily gain showed a quadratic response to increasing HI meal in the grower period(minimum corresponding to the HI6 group).No effects of dietary inclusion levels were observed for the daily feed intake or feed conversion ratio.The apparent dry matter and organic matter digestibility were not affected by the dietary treatment.A linear decrease was observed for the crude protein apparent digestibility in the starter period(minimum for the HI9 groups).The ether extract apparent digestibility increased linearly during the grower and finisher periods(minimum for the HI0 group).The morphometric indices were not influenced by the dietary treatments.Conclusions: The inclusion of up to 9% of HI partially defatted larva meal in the diet of ducks did not cause any effect on growth performance,as well as the apparent digestibility.Moreover,dietary HI inclusion preserved the physiological intestinal development.展开更多
基金supported by the National Key Research and Development Program of China(2021YFD1800200)the Laboratory for Lingnan Modern Agriculture Project(NT2021007)the China Agriculture Research System of the MOF and MARA(CARS-41-G12)。
文摘Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.
基金Research supported by the University of Torino(Italy)funding:SCHA_RILO_16_02
文摘Background: The present work is aimed at evaluating the effect of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens,L.;HI) larva meal for ducks.A total of 192 female 3-day-old Muscovy ducklings(Cairina moschata domestica,Canedins R71 L White,Grimaud Freres Selection,France) were divided into 4 groups,assigned 4 different dietary treatments(6 replicates/treatment and 8 birds/replicate) and reared from 3 to 50 days of age.HI larva meal was included at increasing levels(0,3%,6% and 9%,HI0,HI3,HI6 and HI9,respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter(3–17 days of age),grower(18–38 days of age) and finisher(39–50 days of age).The growth performance and apparent total tract digestibility were evaluated during the trial using titanium dioxide as an inert marker(0.3% of inclusion).At 51 days of age,two birds per pen were slaughtered and histomorphological investigations were performed.Results: The live weight and average daily gain showed a quadratic response to increasing HI meal in the grower period(minimum corresponding to the HI6 group).No effects of dietary inclusion levels were observed for the daily feed intake or feed conversion ratio.The apparent dry matter and organic matter digestibility were not affected by the dietary treatment.A linear decrease was observed for the crude protein apparent digestibility in the starter period(minimum for the HI9 groups).The ether extract apparent digestibility increased linearly during the grower and finisher periods(minimum for the HI0 group).The morphometric indices were not influenced by the dietary treatments.Conclusions: The inclusion of up to 9% of HI partially defatted larva meal in the diet of ducks did not cause any effect on growth performance,as well as the apparent digestibility.Moreover,dietary HI inclusion preserved the physiological intestinal development.
