Yang H.,Chinese Academy of Agricultural Sciences |
Chen Y.,Chinese Academy of Agricultural Sciences |
Qiao C.,Chinese Academy of Agricultural Sciences |
Xu C.,Shandong Academy of Agricultural Sciences |
And 4 more authors.
Veterinary Microbiology | Year: 2015
During 2006 and 2007, two swine-origin triple-reassortant influenza A (H1N2) viruses were isolated from pigs in northern China, and the antigenic characteristics of the hemagglutinin protein of the viruses were examined. Genotyping and phylogenetic analyses demonstrated different emergence patterns for the two H1N2 viruses, Sw/Hebei/10/06 and Sw/Tianjin/1/07. Sequences for the other genes encoding the internal proteins were compared with the existing data to determine their origins and establish the likely mechanisms of genetic reassortment. Sw/Hebei/10/06 is an Sw/Indiana/9K035/99-like virus, whereas Sw/Tianjin/1/07 represents a new H1N2 genotype with surface genes of classic swine and human origin and internal genes originating from the Eurasian avian-like swine H1N1 virus. Six-week-old female BALB/c mice infected with the Sw/HeB/10/06 and Sw/TJ/1/07 viruses showed an average weight loss of 12.8% and 8.1%, respectively. Healthy six-week-old pigs were inoculated intranasally with either the Sw/HeB/10/06 or Sw/TJ/1/07 virus. No considerable changes in the clinical presentation were observed post-inoculation in any of the virus-inoculated groups, and the viruses effectively replicated in the nasal cavity and lung tissue. Based on the results, it is possible that the new genotype of the swine H1N2 virus that emerged in China may become widespread in the swine population and pose a potential threat to public health. © 2014 Elsevier B.V.
Qiao J.,Tianjin Institute of Animal Husbandry and Veterinary Science |
Qiao J.,China Agricultural University |
Li H.H.,Tianjin Institute of Animal Husbandry and Veterinary Science |
Zheng Ch.J.,Tianjin Institute of Animal Husbandry and Veterinary Science |
And 3 more authors.
Journal of Animal and Feed Sciences | Year: 2013
This study was conducted to investigate the effects of crude Aloe vera polysaccharide AVP on the growth performance and immune function of weaned piglets. A total of 200 (Landrace Yorkshire Duroc) weaned pigs at 21 d with initial 8.88 ± 0.49 kg body weight (BW) were allotted to one of four dietary treatments in a randomized complete block design according to their sex and BW (5 replicates with 10 pigs per pen, 5 gilts and 5 barrows). Dietary treatments included one basal diet, and three diets with AVP supplementation (0.05%, 0.1%, or 0.2%). Average daily gain (ADG), average daily feed intake (ADFI), and feed:gain (F:G) ratios were calculated at the end of the experiment. Separated serum samples from each treatment were assayed at the end of the experiment for the concentrations of cytokines and the blocking rate of antibodies against classical swine fever virus (CSFV). Supplementation of AVP at 0.1% improved (P< 0.05) ADG compared with the control group. No significant differences in ADFI or F:G were observed between AVP-treated and untreated control piglets. All AVP-treated pigs had a significantly lower incidence of diarrhoea (P < 0.05) when compared with control pigs. Feeding AVP resulted in increasing (P < 0.01) IL-2 and IFN-y (at 0.1% and 0.2%) and IL-4 (at 0.05%, 0.1% and 0.2%), and in no significant changing of IL-10 (P> 0.05). Supplementation of AVP at 0.05%, 0.1% and 0.2% increased (P < 0.01) the blocking rate of antibodies against CSFV. These results indicate that dietary supplementation with dietary AVP enhanced growth performance in weaned piglets by improving immune function, decreasing the incidence of diarrhoea.