Duck plague is an economically devastating viral disease prevalent in ducks which causes massive loss of duck populations annually. High morbidity and mortality are characteristic of the infection and outbreaks. Duck plague is reported from time to time from different parts of our country including Assam. The infected ducks manifest clinical signs like photophobia, partially or completely closing of eyelids, excessive thirst, nasal discharge, anorexia, drooped plumage, ataxia, diarrhea with soiled vents along with tremors in the head, neck and body. Present study was aimed to evaluate the deleterious effects of duck plague virus on liver and kidney condition by estimating liver and kidney specific biomarkers from indigenous ducks, namely Pati, Nageswari and Cinahanh of Assam from different agroclimatic zones. Study&nbsp; revealed significant increase of AST, ALT, ALP, uric acid and creatinine which is indicative of disruption of healthy function of liver and Kidney due to duck plague virus infection.

Alteration of Liver and Kidney Specific Biomarkers in Indigenous Ducks Infected with Duck Plague Virus

Gracilaria sp is as eaweed with carbohydrate-rich wastes. Its symbiont, Brotia sp,is rich in calcium and protein. The effects of Gracilaria&rsquo;s wastes (GW) as formulated feed supplement on carcass characteristics and production efficiency of local Indonesian ducks. Data were collected from 120 ducks fed either a basal dietor a fermented Gracilaria&rsquo;s wastes supplemented diet (FGW). Treatment levels of FGW were 10%, 12.5%, and 15%. The highest level of meat antioxidant status was reached at 15% FGW, while the optimum level of &nbsp;FGW for decreasing the fat content was 12.5%. The best reduction in meat fat mass was at 15% FGW. Further more, duck feed with FGW resulted in lower average and normalized costs and increased income than observed with the basal diet. Thus, GW as a feed supplement effectively ameliorated the productivity and carcass quality of indigenous Indonesian ducks.

Effect of duck diet supplemented with fermented seaweed wastes on carcass characteristics and production efficiency of indigenous Indonesian ducks

<div>Indigenous ducks are important biodiversity resources and genetic reservoirs needed for mitigating future challenges of food insecurity even though they are highly prejudiced in some parts of Nigeria. They can compare favourably with chickens to produce meat and egg, can adapt to different climatic conditions since raising them does not require elaborate houses. These ducks are known for their high hatching rate that is higher than any other local poultry species and also have the potential to perform better under improved management systems. Average body weight of 2.7 and 1.6 kg have been reported for drakes and females respectively, egg weight of about 50-60 g have equally been reported. Each duck can lay between 60-80 eggs annually under scavenging conditions, while meat from duck is rich in unsaturated fatty acids which are advantageous for human health. Wide variations in phenotypic traits and also high genetic diversity exist among ducks. Thus the findings of this paper suggest that the genetic makeup of these ducks have not been altered through selective breeding therefore, their genetic improvement and conservation is highly essential towards achieving food security.</div>

Characteristics of Indigenous Ducks and Their Production System in Nigeria: A Review

<div>Background: Duck farming plays a significant role, next to chicken in the socio-economic uplift men of the rural farmers of North-East India. Pati duck is the most common duck breed in the Brahmaputra valley of Assam and the other common variety reared in North-East India is Chara-Chambeli, however it originatein Kerala. Genetic characterization plays a significant role for formulation of breeding strategies for improvement of any breed. Microsatellites are codominant in nature and are highly polymorphic. High level of allelic variation, co-dominant mode of inheritance and potential for automated analysis make them an excellent tool for genotyping, mapping and genetic characterization. Pati duck is the most common duck breed&nbsp; in the Brahmaputra valley of Assam and the other common variety reared in North-East India is Chara-Chambeli however its origin in Kerela. Therefore, the present investigation was carried out to characterize these two duck breeds using microsatellite markers to evaluate the genetic diversity in these two duck population. 
 
Methods: For the present study, Blood sample were collected from 50 Patiducks and 50 Chara-Chambeli ducks from different parts of North-East India. Assessment of genetic characterization of duck breeds of north-east region were carried out using 16 microsatellite markers and population genetics analysis were done by POPGENE software. 
 
Result: In the present study, all the studied loci were highly polymorphic. Analysis generated a total of 41 microsatellite alleles. The number of observed alleles (Na) with an overall mean of 1.93&plusmn;0.258. However, the effective number of alleles (Ne) with a mean of 1.6933&plusmn;0.2712. The Shannon&rsquo;s information index was found to a mean value of 0.5685&plusmn;0.1693. The overall means for observed (HO) and expected (He) heterozygosities were 0.2889&plusmn;0.2477 and 0.5289&plusmn;0.0853, respectively. The chi-square (&chi;2) test for Hardy-Weinberg equilibrium revealed that all the loci are in within Hardy-Weinberg equilibrium.</div>

Genetic Characterization of Indigenous Duck of North-East Region using Microsatellite Markers

Background: Duck farming is one of the major income generating enterprise, promoting&nbsp; rural&nbsp; economy in India. The occurrence of infectious diseases is the major bottle neck in the profit generation process of duck rearing. Duck cholera is one of the major bacterial infections, commonly noticed in 4 to 11 weeks age of egg laying ducks caused by Pasteurella multocida, leading to high mortality in ducklings whereas adult as well as meat type ducks are resistant. The present communication describes pathomorphology of acute duck cholera in Vigova Super M meat type breeder flock. 
 
Methods: An investigation was carried out to ascertain the possible cause of increased mortality in an intensively maintained 1000 Vigova Super M meat type breeder flock of 25 week old during the month of July 2023. Necropsy examination conducted on five dead birds and samples collected and subjected for bacteriological and pathological examination. 
 
Result: Affected breeder duck flocks&nbsp; showed cumulative mortality of 18 per cent. Clinical signs of depression, inappetance, mild conjunctivitis and mucus discharge from nostril for one or two days followed by death were noticed. At necropsy, hepatomegaly and splenomegaly with multifocal cream-colored foci randomly distributed throughout the parenchyma, vascular changes in various visceral organs were noticed. Impression smear of visceral organs of dead birds revealed bipolar organisms which was confirmed as&nbsp;Pasteurella multocida by cultural and biochemical examination. Microscopically, there was multifocal splenic and hepatic necrosis with intralesional rod-shaped bacteria. In conclusion, this investigation indicated that the adult breeder ducks susceptible to duck cholera,&nbsp; exhibiting pathomorphological features similar to young ducklings.

Pathomorphology of Acute Duck Cholera Infection in Meat Ducks

Background: One of the major diseases affecting ducks is Duck Virus Enteritis causing heavy mortality and high economic losses in duck farming.&nbsp; 
 
Methods: In this study, in ovo vaccination technology was adopted using a Duck Embryo Fibroblast passaged Duck Virus Enteritis vaccine virus. This would be the first reported use of in ovo vaccination in ducks against a viral disease. Virus Neutralisation Test was used to measure the immune response after standardisation of the technique using hyperimmunised Barred Plymouth Rock rooster. An optimised dose of the Duck Virus Enteritis vaccine virus was computed using Embryo Lethal Dose50 assessment of hatchability. In ovo vaccination was done in 2 groups of 40 embryos each, one group acting as negative control and the other group as virus treatment group. A booster dose was given to the treatment group on 14th day post hatch.&nbsp; 
 
Result: Virus Neutralisation test using a beta method was carried out to measure the immune response. The treatment group showed an immune response of 3.33&plusmn;0.21 Log2 Antibody titre. This opens up a plethora of options of application of in ovo vaccination in ducks against viral diseases which would be a boon to the duck farming industry.

In ovo Vaccination in Ducks against Duck Virus Enteritis

<div>Background:&nbsp;Escherichia coli and Klebsiella pneumoniae are two important commensals with pathogenic potentiality in animals and birds, causing intestinal and extra-intestinal infections. These are somewhat zoonotic too via different routes. So, the present study was undertaken to investigate the prevalence of these two bacteria from cloaca and environment of ducks from different districts of West Bengal, followed by detailed characterization and antibiogram. 
 
Methods: Around 197 duck and environmental samples were collected from different districts of West Bengal. E. coli and K. pneumoniae were isolated from collected samples as per standard methods followed by serotyping of the E. coli isolates. The detection of ESBL/ACBL producing isolates was done both phenotypically and genotypically by detecting the presence of antibiotic-resistant genes. Virulence property and biofilm-producing ability of these isolates were also studied. Antibiogram of the ESBL and biofilm positive isolates were done using common 12 antibiotics by disc diffusion method.&nbsp; &nbsp; 
 
Result: A total of 134(68.02%) Escherichia coli and 33(16.75%) Klebsiella pneumoniae isolates were recovered and confirmed by PCR. The prevalence of E. coli and K. pneumoniae in cloacal swabs were less in comparison to the environmental samples (72.09% and 20.93%). Approx. 79.85% E. coli and 72.73% K. pneumoniae isolates were found to be the ESBL/ACBL producers in vitro. E. coli and K. pneumoniae isolates possessed all major antibiotic-resistant genes with the blaAmpC (64.18% &amp; 48.48%) being the most prevalent one. Twenty three (17.16%) E. coli isolates were found positive for the virulence genes, of which stx1 (39.13%) was the most common one as detected by multiplex PCR. No virulence gene was found in K. pneumoniae isolates. Ninety one (67.91%) E. coli and 26(78.79%) K. pneumoniae isolates possessed the biofilm-producing genes. All the ESBL and biofilms producing E. coli and K. pneumoniae isolates showed 100% - 95.24% resistance to ampicillin. A high percentage of resistances were also seen against cefotaxime, ticarcillin/ clavulanic acid, ertapenem, ceftazidime, norfloxacin and ciprofloxacin, which may be due to several reasons. Maximum overall sensitivity was detected against chloramphenicol, co-trimoxazole and gentamicin.</div>

Detection and Characterization of &beta;​-lactamases and Biofilm-producing Escherichia coli and Klebsiella pneumoniae from Ducks and Duck Environments in West Bengal

<div style="text-align: justify;">An investigation was carried out to compare the serum biochemical profile of two prominent avian species: &nbsp;ducks vis a vis chickens, at peak egg production phases. The genotypes consisted of 3 breeds of ducks: Khaki Campbell, White Pekins and a native duck breed: Kuzhi (reared in Odisha and adjoining regions) and besides the White Leghorn chickens, at 50 week age, numbering 30 each, with rearing done in individual cages. The result revealed significant (p&lt;0.0001) genotype-associated differences for almost all the serum biochemical parameters, except globulin. There existed a significant (p&lt;0.0001) difference between the species (duck verses chicken) for these parameters, with distinct inter-breed variations. Among the lipid profile HDL of ducks remained comparable to that of chickens, with the indigenous Kuzhi ducks displaying the most desirable lipid-profile of all the genotypes except LDL. The serum liver-enzymes (SGOT and SGPT) were well within normal ranges, expected or laying birds with significant difference between species, with between-breed variations among ducks. It was concluded that, ducks had significantly-distinct and variant serum biochemical profiles compared to chickens, where the indigenous ducks (of Odisha region) possessed the most- desirable estimates, as expected from table- egg laying species.&nbsp;</div>

<div style="text-align: justify;">Comparative Serum Biochemical Profile for Different Breeds of Ducks versus White Leghorn Chickens in Peak Laying Period</div>

Indigenous ducks play a vital role in sustainable livelihood of the poor duck farmers. In Tamil Nadu, two popular indigenous duck varieties viz., Sanyasi and Keeri are being reared traditionally by the duck farmers under nomadic system. In the same way, Kuttanad ducks are popular in Kerala and Assam ducks are popular in Assam. The present research work was undertaken to study the genetic distance between and within the indigenous ducks and exotic duck breeds by using duck specific microsatellite markers. From the blood samples the genomic DNA was isolated and characterized genetically. With the molecular data, dendrogram was constructed. This revealed that, Keeri, Sanyasi, Kuttanad and Assam ducks formed the first group with White Pekin in the second group and Muscovy in the third cluster. Among the Indian duck varieties, Keeri and Sanyasi ducks of Tamil Nadu were found to be closer to each other as indicated by the genetic distance value of 0.11. However, within this group, 26.33 and 29.87 per cent of differentiation were noticed between Assam and Sanyasi and Assam and Keeri ducks respectively. Higher genetic distance value of 0.92 (92 per cent) was observed between two exotic ducks. Based on the genetic distance and genetic diversity between the indigenous ducks, the duck varieties of Tamil Nadu, Kerala and Assam may be classified as distinct breeds.

Phylogenetic analysis of six duck populations

<div>Background: The variety of indigenous duck germplasm contribute maximum to the poultry industry in India, besides chicken population. In southern part of India, the available duck genetic resource, particularly Arni ducks (comprises of Sanyasi and Keeri ducks) of Tamil Nadu, has its own characteristics with innate potentiality of higher productivity without any input system of management. Genetic characterization and diversity of indigenous duck genetic resources has not been properly studied. In the present study, the genetic diversity of Arni ducks with other indigenous and exotic duck germplasm were analysed with microsatellite markers.&nbsp; 
 
Methods: Genomic DNA was isolated from the blood samples of six duck populations. Molecular characterization was carried out with duck specific FAO recommended microsatellite markers. The genotyping of ducks was done based on the size of 4324 PCR amplicons of 23 microsatellite loci, which were subjected to capillary electrophoresis using automatic sequencer. 
 
Result: A total of 222 alleles in six duck populations across 23 microsatellite loci with a mean of 9.65&plusmn;0.95 alleles were found. Kuttanad duck variety had the highest number of alleles (139) followed by Sanyasi (136), Keeri (129), Muscovy (118), Assam (91) and White Pekin (78) ducks. The mean observed number of alleles was 6.04&plusmn;0.59, 5.91&plusmn;0.76, 5.61&plusmn;3.17, 5.13&plusmn;0.44, 3.96&plusmn;0.76 and 3.39&plusmn;0.40 in Kuttanad, Sanyasi, Keeri, Muscovy, Assam and White Pekin ducks respectively. The overall mean polymorphism information content (PIC) values among the six duck populations was 0.6269. &nbsp;In most of the duck populations, the mean PIC value was more than 0.5 except in Assam (0.4815) and White Pekin (0.3725) ducks. The observed heterozygosity was the highest in Keeri ducks (0.5217) and lowest in White Pekin ducks (0.2766), while, the mean expected heterozygosity was the highest in Sanyasi (0.5628) and lowest in White Pekin (0.4038) ducks. The variations in the observed and expected number of alleles, differences in PIC of various microsatellite loci might be attributed to the genetic variability of the duck populations, number and type of microsatellite primers utilised for analysis and the genetic diversity of the duck breeds under study. Higher FST value indicates the substantial degree of breed differentiation among the studied duck populations.</div>