Transcription factor forkhead box L2 (FOXL2) and growth differentiation factor-9 (GDF9) genes have critical roles in the regulation of hen ovarian development. In the present study, these genes were explored as possible molecular markers associated with BW, hen-housed egg production, and egg weight in Chinese Dagu hens. Samples were analyzed using the PCR-single strand conformation polymorphism (PCR-SSCP) technique followed by sequencing analysis, and two novel single nucleotide polymorphisms (SNPs) were identified within these candidate genes. Among them, an A/G transition at base position 238 in the coding region of the FOXL2 gene and a G/T transversion at base position 1609 in exon 2 of the GDF9 gene were found to be polymorphic and named SNPs A238G and G1609T, respectively. The SNP A238G (FOXL2) leads to a nonsynonymous substitution (isoleucine77-to-valine), and when the 360 Dagu hen samples were divided into genotypes AA and AB, allele A was found to be present at a higher frequency. Furthermore, the AA genotype correlated with significantly higher hen-housed egg production at 30, 43, 57, and 66 wk of age and with a higher egg weight at 43 wk (P<0.05). For the SNP G1609T (GDF9), the hens were typed into TT and TC genotypes, with the T allele shown to be dominant. The TC genotype was also markedly correlated with higher hen-housed egg production and a higher egg weight (P<0.05). Moreover, four haplotypes were reconstructed based on these two SNPs, with the AATC haplotype found to be correlated with the highest hen-housed egg production at 30 to 66 wk of age and with higher egg weights at 43 wk (P<0.05). Collectively, the two SNPs identified in this study might be used as possible genetic molecular markers to aid in the improvement of egg production traits in chicken breeding.

Aims Genotype VII Newcastle disease (ND) is one of the most epidemic and serious infectious diseases in the poultry industry. A novel vaccine targeting VII Newcastle disease virus (NDV) is still proving elusive. Methods and Results In this study, we constructed regulated delayed lysis Salmonella strains expressing either a fusion protein (F) alone under an eukaryotic CMV promoter or together with chicken IL‐18 (chIL‐18) as a molecular adjuvant under prokaryotic Ptrc promoter, named pYL1 and pYL23 respectively. Oral immunization with recombinant strains induced NDV‐specific serum IgG antibodies in both pYL1‐ and pYL23‐immunized chickens. The presence of chIL‐18 significantly increased lymphocyte proliferation in immunized chickens, as well as the percentages of CD3+CD4+ and CD3+CD8+ T cells in serum, even if a statistically significant difference did not exist. After a virulent challenge, pYL23 immunization provided about 80% protection at day 10 postinfection, compared with 60% of protection offered by pYL1 immunization and 100% protection in the inactivated vaccine group, indicating the enhanced immune response provided by chIL‐18, which was also confirmed by histochemical analysis. Conclusions Recombinant lysis Salmonella‐vectored DNA vaccine could provide us a novel potential option for controlling NDV infection. Significance and Impact of the Study This study took use of a regulated delayed lysis Salmonella vector for the design of an orally administrated vaccine against NDV.

Background: Cross-breeding is the main strategy for improving the economic traits of livestock and poultry within a short time. But there are only a few studies on the comparative assessment of different cross-breeding methods to poultry reproductive performance. Methods: Here, intersect, back, upgrading and three-way cross-breeding strategies are employed for quantitative comparison of male reproductive performance using Carlos goose, Jilin White goose and Siji goose. The fertility rates and testis weight were analyzed and compared among the five cross-breeding groups. Also, the seminiferous tubule diameter and sperm concentration were measured. The mRNA levels of two reproduction-related genes, GnRH (gonadotropin-releasing hormone) and PRL (prolactin) were quantitatively measured and compared using the qPCR technique. Result: Finally we found that the three-way cross strategy had the biggest advantage for improving male reproductive performance according to the analysis of fertility rate and testis structure. Also all these data we measured suggested that the three-way cross strategy was beneficial to male reproductive performance and thus we provided a theoretical basis for making appropriate cross-breeding plans.