Tracking domestic ducks:A novel approach for documenting poultry market chains in the context of avian influenza transmission

Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System （GPS） locations and send them through the Groupe Spécial Mobile （GSM） cellular telephone system. For the ifrst time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide di-rect, quantitative information to document the movement of poultry and reveal their market chains. Our ifndings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.

Effects of foraging site distances on the intestinal bacterial community compositions of the sympatric wintering Hooded Crane(Grus monacha)and Domestic Duck(Anas platyrhynchos domesticus)

Background:The composition of intestinal microflora in animals is affected by cross-species transmission.In a nature reserve,the foraging sites of waterbirds are relatively fixed,but frequently close to residential areas and can also be visited by domestic fowls.It is easy to result in the trans-species-flock dispersal of gut microbes between the wild birds and domestic fowls.The effects of the variable foraging site distances on the gut microbe structures of the waterbirds and the sympatric domestic fowls are currently unclear,and further research is required to evaluate the impacts of geographic location on cross-infection.Methods:Illumina high-throughput sequencing and bioinformatics analysis software were utilized to compare and analyze the composition of gut microbes from the fecal samples of Hooded Cranes(HC;Grus monacha)and two groups of Domestic Ducks(Anas platyrhynchos domesticus)that foraged at 1 km(ducks in near areas,D-N),and 4 km(ducks in far areas,D-F)away from the habitats of the Hooded Cranes at Shengjin Lake,China.Results:The results showed that there were significant differences in the alpha-diversity of the gut bacteria in the HC,D-N,and D-F samples under the interspecific distance factor.The dominant bacterial phyla,Cyanobacteria and Proteobacteria,showed correlations with distance for each host.The D-N group had more diverse intestinal flora than the D-F,as they were physically closer to the HC and had more indirect contact and cross-transmission of their gut microbes.More potentially pathogenic bacterial sequences,and Operational Taxonomic Units(OTUs)were found in the D-N than in HC and D-F.Conclusions:Hooded Cranes and the Domestic Duck populations at variable distances from the cranes showed significant differences in their intestinal bacteria and potentially pathogenic bacteria.The closer the foraging sites were,the easier the intestinal flora spread across species.The results provide a basis for determining the safe distance between wild birds and domestic fowls in a nature reserve.

Analysis of the Genetic Diversity and Origin of Some Chinese Domestic Duck Breeds

Twelve fluorescence-labeled microsatellite markers were used to analyze the genetic diversity of 12 domestic duck breeds and 2 wild duck breeds to determine the relationship and origin of Chinese domestic duck breeds. Gene frequency, effective number of alleles （Ne）, expected heterozygosity （He）, polymorphism information contents （PIC）, inbreeding coefficient in population （Fis）, standard genetic distance （Ds）, and genetic distance （DA） were calculated by FSTAT and distance and phylogenetic analysis after the dates which were output from the Microsatellite-Toolkit software. Genetic distances between 12 domestic duck breeds and 2 wild duck breeds were analyzed by variance analysis. Unweighted pair group method with arithmetic mean （UPGMA） and phylogenetic trees used for cluster analysis were structured. The results indicated that 11 loci had medium- or high-level genetic diversity among the 12 loci, which could be efficiently used in the detection of the genetic parameters of each population. The values of He were 0.5414 to 0.7343, those of PIC proved similar, and those of Fis were 0.1101 to 0.3381 among all populations. All breeds were clustered into three groups by UPGMA phylogenetic trees. Banzui duck was clustered into a separate group. Differences of the DA were analysed by t-test. The results showed that difference in DA between the 12 domestic duck breeds and Lvtou duck and the Banzui duck were very significant （P〈0.01）, indicating that these 12 domestic duck breeds originated from Lvtou wild duck, but not Banzui duck.

AFLP analysis of genetic diversity and relationship among some Chinese domestic ducks and wild ducks

The amplified fragment length polymorphic(AFLP)technique was used to analyze the genome DNA polymorphism among 8 breeds of domestic ducks and 2 species of wild ducks.Nine of the 17 selected primers pairs gave reproducible polymorphic DNA amplification bands.The amplified bands ranged from 44 to 83 per primer pair.Of the 513 AFLP markers obtained,498 were polymorphic.The proportion of polymorphic loci was 97.1%.The genetic distance(D)and similarity coefficients(GS)were calcu-lated based on the polymorphic data.Between domestic ducks D ranged from 0.331 to 0.589,while between domes-tic ducks and the wild ducks,it ranged from 0.298 to 0.520(vs.Anas Platyrhynchos)and from 0.316 to 0.522(vs.A.Poecilorhyncha),respectively.The variance analysis showed no significant difference between the two groups of data,which indicated that both mallard and spot-billed ducks made contributions to domestic duck evolution.A dendrogram was constructed according to the D value.

A New Detecting Method for the Sequence Difference of CHD1 Gene on Sex Chromosomes Z and W in Domesticated Ducks of China

A new method for detecting the sequence differences of duck Chromo-helicase-DNA-Binding 1 （ CHD1 ） genes on sex chromosomes Z and W was established by amplifying DNA fragment length poly morphism, which aimed to solve some technical problems, such as the sex identification with nondamage, the misclassifc rate of artificial sex identification during embryonic period, and the injury caused by anal reversal identification method during neonatal period. The im- proved sex identification method was developed by DNA amplified fragment length polymorphism by using CHD1 gene sequence in bird. The sex identification PCR primers YPF/YPR were used, and the PCR product was cloned, sequenced and blasted; and the effectiveness and accuracy of this method were verified through liv- ing examples. 2% agarose gel electrophoresis was used to distinguish 495 bp CHD1-Z and 351 bp CHD1-W obtained by primer YPF/YPR. The female （ZW） dis- played two visible bands; while male （ZZ） had only one single band. It was proved that this method for detecting the sequence differences of duck CHD1 gene was visual and reliable, and the molecular marker provided was effective and precise in the sex molecular biological identification of domesticated duck in China.

Uranium Metabolism Associated with Ontogenetic Growth of Birds—Case Studies with Broilers and Ducks

Cobb broilers and domestic ducks, both one-day-old, were treated using ration doped with 20 ppm of uranyl nitrate. Uranium concentrations in the tibia (μg-U/g-bone) were measured by neutron activation analysis as function of the animals’ age, from the neonatal period to maturity. Results show that Uranium and Calcium qualitatively follow the same metabolic pathway, and that adult ducks incorporate on average ten times more Uranium than broilers. Data interpretation shows that the Uranium clearance rate in broilers is substantially higher than that in ducks, suggesting that metabolic characteristics favoring Calcium retention in bone may hinder the elimination of Uranium in ducks. The need for further comparative biochemistry studies between Galliformes and Anseriformes is addressed.

Circulation of the low pathogenic avian influenza subtype H5N2 virus in ducks at a live bird market in Ibadan, Nigeria

Background:To monitor carrier hosts of avian influenza in Nigeria,we randomly collected cloaca swab specimens from 155 ducks at a live bird market(LBM)in Ibadan,southwest Nigeria,between July 2011 and July 2012.Methods:The samples were analyzed by real-time reverse transcription-polymerase chain reaction(RT-PCR)and virus isolation was carried out in embryonated chicken eggs.Partial sequencing of the antigenic cleavage site of the haemagglutinin(HA)gene was performed,multiple sequence alignment was carried out using ClustalW,and a phylogenetic tree was constructed using the neighbor joining method.Results:Twenty(13%)of the 155 samples were positive for avian influenza subtype H5N2 by real-time RT-PCR and three isolates were obtained from embryonated chicken eggs.Partial sequencing of the amino acid cleavage site of the HA genes of two isolates corresponded to a PQRETGL*F sequence that is common in low pathogenic avian influenza(LPAI).Phylogenetically,the HA genes of the two influenza viruses are monophyletic and clustered with H5N2 viruses detected in wild ducks from Africa.Conclusion:The occurrence of LPAI in domestic ducks in Nigeria underscores the importance of continuous surveillance and monitoring of the virus(in a country that is considered to be free of avian influenza)in order to prevent the emergence of virulent strains that may spread to commercial poultry and humans.