Molecular Characteristics and Phylogenetic Analysis of Short Beak and Dwarfism Syndrome-Related Novel Goose Parvovirus

Short beak and dwarfism syndrome (SBDS) emerged in cherry valley duck flocks in China in 2015, and novel goose parvovirus (NGPV) was proved to be the etiological agent of SBDS. To date, whether SBDS-related NGPV isolates possess common molecular characteristics remains unknown. In this study, three new NGPV strains (namely, SDHT16, SDJN19, and SDLC19) were isolated from diseased ducks showing typical SBDS and successfully passaged in embryonated goose or cherry valley duck embryo. The whole genomes of three NGPV strains shared 98.9%–99.7% homologies between each other but showed slightly lower homologies (95.2%–96.1%) with the classical GPV strains. A total of 16 common amino acid point mutations were produced in the VP1 proteins of six NGPV strains (SDHT16, SDJN19, SDLC19, QH, JS1, and SDLC01) compared with the classical Chinese GPV strains, among which nine amino acid sites were identical to the European GPV strain B. The non-structural protein Rep1 of the six NGPV strains generated 12 common amino acid mutations compared with the classical GPV strains. The phylogenetic analysis indicated that the Chinese NGPV strains clustered with the European SBDS-related NGPV strains, forming a separate branch, distinct from the group formed by the classical GPV strains. Taken together, the present study unveils the common molecular characteristics of the NGPV isolates and directs the conclusion that the Chinese NGPV isolates probably originate from a common ancestor with the European SBDS-related NGPV.

Correlation between chemical composition, EHGE and TME of corn for ducks

Correlations between chemical composition, enzymatic hydrolysate gross energy (EHGE), and true metabolizable energy (TME) of corn for ducks were investigated. Twenty-two corn samples were collected from various regions in 11 provinces of China. The crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), Ash, gross energy (GE), dry matter (DM), amylopectin (AP), amylose (AM), total starch (TS), and AP/AM were determined for each sample. Five of the samples of corn were chosen at the mean, mean ± 1 standard deviation (SD), and mean ± 2 SD based on AP/AM. The EHGE of these samples was analysed using the pepsin-artificial small intestinal fluid enzymatic method. These five samples were also force-fed to male Cherry Valley ducks to assay their TME. Finally, correlation analyses were performed, and regression equations were established. Ash content, GE, and TS were highly related to EHGE. Univariate prediction equations were EHGE = 11.8566Ash-0.0421 (P <0.05), EHGE = 0.1535GE1.5642 (P <0.05), and EHGE = 0.1020TS1.1561 (P <0.05). The total starch, AP/AM, and ash of the chemical compositions were highly related to TME. The corresponding univariate regression equations were TME = 21.9355TS-0.0910 (P <0.05), TME = 15.6590AP/AM-0.0559 (P <0.05), and TME = 15.0778Ash0.0442 (P <0.05). The mean EHGE was equivalent to 78.5% of TME, but their correlation coefficient was low. In conclusion, chemical composition was predictive of EHGE and TME of corn samples for ducks, but the correlation of EHGE and TME was low Keywords: Cherry Valley duck, amylopectin, amylose, true metabolizable energy

Effects of Probiotic (Lactobacillus spp) Mixed with Cassava Leaves (Manihot esculenta) on Growth Performances and Meat Quality of Cherry Valley Duck (Anas platyrhynchos domesticus)

Probiotics are beneficial bacteria that had been used in poultry industry as alternative sources for antibiotic. The aim of this study was to determine the effect of probiotic mixed with cassava leaves (Manihot esculenta) on Cherry Valley Duck (Anas platyrhynchos domesticus) growth performance, carcass characteristics and meat quality. Lactobacillus spp. was used in this experiment to see its effectiveness in enhancing quality of cassava leaves as potential feed towards optimum growth performance of ducks like body weight gain, feed intake and feed conversion ratio, carcass characteristics and meat quality. 34 tails of Cherry Valley ducks aged 14 days with average weight of 500 g were randomly assigned to four treatments in triplicates. Treatments for the 35 days feeding trial were T1 at 0% probiotic + 75% commercial diet + 25% cassava leaves (control), T2 (0.15% probiotic + 75% commercial diet + 25% cassava leaves), T3 (0.30% probiotic + 75% commercial diet + 25% cassava leaves) and T4 (0.45% probiotic + 75% commercial diet + 25% cassava leaves) respectively. Proximate analysis was also conducted to determine nutritional content like protein, lipid, moisture, ash and fiber. Results show that supplementation of probiotic at 0.15% Lactobacillus spp. into 25% of cassava leaves and 75% commercial pellet gave highest body weight gain (BWG), low feed conversion ratio (FCR), highest carcass yield and good meat quality. It can be concluded that inclusion of probiotic at 0.15% in cassava leaves as duck’s diet gives good growth performance and may become an alternative super diet for duck in future.

Porin protein could be a vaccine candidate against Riemerella anatipestifer for ducks

such as domestic ducks and geese. Young birds have a high mortality rate after infection. The resistance caused by the abuse of antibiotics is also getting worse. Since there are 25 serotypes of RA, and the cross-immunization between serotypes is weak, it is necessary to find a vaccine that has cross-immunization against multiple serotypes of RA. In this article, the bioinformatics analysis of RA Proin protein was conducted, and it was speculated that it has the potential of a subunit vaccine. The protein was recombinantly expressed and purified, and immunized with Cherry Valley Duck. The results show that the serum antibodies of the Porin protein immunized group were positive at 1:24300 for the porin protein and RA strains CH1. The serum could improve the killing effect of complement and phagocytic cells on RA. After the challenge, the survival rate of Cherry Valley Duck can be increased by 80%.