To study the effects of melittin on egg-laying performance and intestinal barrier of quails, 240 quails (aged 70 d) were randomly divided into 4 groups with 6 replicates (10 quails per replicate). They were fed with basal diet (group B), basal diet + 0.08 g/kg melittin (group BA1), basal diet + 0.12 g/kg melittin (group BA2) and basal diet + 0.16 g/kg melittin (group BA3). The experiment lasted for 21 days. The eggs were collected every day. At the end of the experiment, duodenal, jejunal, and ileal tissues were collected, and the cecal contents were sampled. Intestinal antioxidant index, barrier function, and intestinal flora were analyzed. The results showed that the addition of melittin significantly increased the laying rate and average egg weight. Addition of melittin significantly increased the antioxidant function, mechanical barrier, immune barrier, and the villus height to crypt depth ratio of small intestine. Addition of melittin had no significant effect on the α and β diversity of cecal flora, but significantly increased the abundance of Bacteroidales at family level and genus level. Bioinformatics analysis of cecal content showed significant increase in COG functional category of cytoskeleton, and significant decrease in RNA processing and modification in group BA2. KEGG functional analysis showed significant decrease in steroid biosynthesis, caffeine metabolism, and cytochrome P450 pathways in group BA2. In conclusion, addition of 0.12 g/kg melittin to feed improved the laying performance and the intestinal antioxidant capacity and barrier function of quails but had no significant effect on the composition and structure of cecal microbial community. This study provides experimental data and theoretical basis for the application of melittin as a new quail feed additive.

Objectives: Ferulic acid is a natural and safe herbal feed additive. This study aims to evaluate the effects of ferulic acid on the growth performance, anti-inflammatory and antioxidant capacities, immune function, and intestinal microbiota of broiler chickens. Methods: A total of 320 broiler chickens, aged 14 days, were randomly divided into four groups: a blank control group (MA group), a low-concentration ferulic acid group (BM group, 10 mg/kg), a medium-concentration ferulic acid group (CM group, 30 mg/kg), and a high-concentration ferulic acid group (DM group, 90 mg/kg) after a 14-day acclimatization period. The experiment lasted for 28 days, and the chickens were dissected on day 29. Results: The results showed that compared to the MA group, the feed-to-meat ratio in the CM and DM groups was significantly reduced. The activity of duodenal trypsin in the CM and DM groups was significantly enhanced, and the activity of pancreatic protease in the DM group was significantly increased. The serum levels of urea nitrogen, creatinine, and triglycerides were significantly elevated in the CM and DM groups. The serum malondialdehyde (MDA) levels in the BM, CM, and DM groups were significantly reduced, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were significantly increased in the CM and DM groups. The serum interleukin-2 (IL-2) levels in the BM group were significantly decreased, while interferon-gamma (IFN-γ) levels in the CM group and complement component 3 (C-3) levels in the DM group were significantly increased. The mRNA expression levels of TLR4, MyD88, NF-κB, TNF-α, NLRP3, IL-1β, and IL-18 in the jejunum of the DM group were significantly reduced. The diversity of cecal microbiota in the ferulic acid groups changed, with a certain degree of increase in the relative abundance of Spirulina and Ruminococcus. The relative abundance of Escherichia coli in the DM group significantly increased, altering the metabolic function of the cecal microbiota in broiler chickens. Conclusions: The above results indicate that ferulic acid, as a novel feed additive for broiler chickens, has an impact on the growth performance, anti-inflammatory and antioxidant capacity, immune function, and intestinal microbiota of broiler chickens.

This study aimed to identify candidate genes regulating ovarian development following ovarian tissue transplantation through transcriptome sequencing (RNA-seq) and weighted gene co-expression network analysis (WGCNA). Ovarian tissues were collected from 10 thirty-day-old donor chickens, and each ovary was divided equally into three parts of similar size, and transplanted in situ into two-day-old recipient chickens. Samples were collected on days 0 (untransplanted), 6, and 12 after transplantation. RNA was extracted from ovarian samples for construction of a transcriptome library, and then sequenced on the IlluminaHiSeqTM2000 sequencing platform. The sequencing results were evaluated to determine differentially expressed genes (DEGs) through GO function and the KEGG pathway analyses, Gene Set Enrichment Analysis (GSEA), WGCNA, and PPI networks. Some candidate genes were further validated through real-time fluorescence quantitative PCR (RT-qPCR). RNA-seq analysis identified 2242 up-regulated and 3095 down-regulated DEGs at 6 days after ovarian transplantation, and 2181 up-regulated and 2129 down-regulated DEGs were identified at 12 days after transplantation. Enrichment analysis showed that the genes were enriched in multiple inflammatory pathways, pathways involved in signal transduction and cellular processes. Through the WGCNA, five modules were constructed, from which 4 and 5 candidate genes were mined at 6 and 12 days after ovarian transplantation, respectively. Transcription factor prediction showed that GTF3A was the most important transcription factor. The results of RT-qPCR verification confirmed that the expression profile of 8 candidate genes was consistent with that of the sequencing results. In summary, this study presents the candidate genes involved in ovarian vascular remodeling and ovarian proliferation after ovarian transplantation.

Gut microbiota plays an important role in animal health, production and diseases. Little is known about whether heat stress alters the composition of quail gut microbiota; therefore, we studied the effects of heat stress on growth performance, antioxidant functions, heat shock proteins and caecal microbiota. Two groups of 40 (20-day-old) quails were set up, including a control reared at 24 ± 2°C and a heat stress group subjected to heat stress at 36 ± 2°C for 4 h per day for 7 consecutive days. We found that heat stress significantly elevated the relative expression levels of HSP70 and HSP90 mRNA in the thymus, bursa and spleen by real-time fluorescence quantitative PCR assay, indicating successful establishment of the experimental model. Heat stress was found to have an effect on gut microbiota composition. At the genus level, Alistipes were significantly increased in the heat stress group. PICRUSt2 function prediction revealed that most of the KEGG pathways with high temperature-induced abundance differences are metabolism-related. These data indicated that heat stress reduced the production performance of quails by affecting antioxidant functions, as well as the composition and structure of the intestinal microbiota. The results of this study provide technical information for conducting research on heat stress prevention and control techniques in quails.