This study investigated the effects of floor and cage rearing systems on performance, meat quality, and enteric microorganisms of male and female yellow feather broilers.  Two hundred Xueshan chickens (42 days old; 100 of each sex) were divided into four groups, according to sex and rearing system (stainless-steel cage or litter floor).  Male and cage-reared broilers exhibited better (P<0.001) performance and higher (P≤0.001) eviscerated percentage than female and floor-reared broilers.  The interaction between rearing system and sex had an effect (P<0.05) on the percentage of breast and thigh muscles.  Female floor-reared broilers presented the highest (P<0.02) percentage of breast and thigh muscles among all the groups.  In both sexes, the abdominal fat content in cage-reared broilers was higher (P<0.01) than that in floor-reared broilers.  Female cage-reared broilers exhibited better (P<0.05) meat quality of breast muscle than other groups.  An analysis of welfare observations indicated that the feather quality of floor-reared broilers was better (P<0.01) than that of cage-reared broilers, whereas the gait scores were not significantly affected (P>0.05) by rearing system.  The enteric microbiota assessment by 16S rRNA amplicon-based sequencing showed that Firmicutes, Proteobacteria, and Bacteroidetes were the most prevalent phyla in both rearing systems, and that the cecum was relatively stable in terms of microbiome composition.  Floor-reared broilers exhibited a richer diversity of bacteria in the intestinal tract than cage-reared broilers, while alpha diversity was not significantly different (P>0.05) among the groups.  The ratio of Bacteroidetes to Firmicutes and the abundance of Helicobacter and Romboutsia could potentially affect the production of broilers.  These findings indicate that cage rearing improved the production of male Xueshan broilers, which may be due to the difference in enteric microbiota between cage and floor rearing systems. 

Follicle-stimulating hormone (FSH), an important hypothalamic-pituitary-gonadal axis (HPG) hormone, is secreted by the pituitary gland.  This study confirms that FSH is expressed in chicken follicles at different stages, and positive FSHβ mRNA signals were stronger (P<0.05) in granulosa cells than in oocytes.  The 369 bp coding sequence of FSHβ in ovaries is 100% identical to that in the pituitary gland.  The experiment in vitro revealed that the ovary possessed FSH secretory capacity.  Further, FSHβ mRNA was significantly upregulated (P<0.05) in follicles and significantly higher (P<0.05) than that in the pituitary gland by approximately 2–23 times with the development.  The number of granulosa cells decreased significantly (P<0.05) in the cells with siRNA treatment, confirming that the ovarian FSH could promote granulosa cell proliferation.  This view was supported by cell cycle analysis and CCND2 and CCNE2 expression.  Further research indicated that no difference (P>0.05) was observed between the number of granulosa cells treated with FSHβ siRNA and in exogenous FSH. However, the number of granulosa cells without FSHβ siRNA transfection was significantly higher (P<0.05) for exogenous FSH.  This finding suggests that the proliferative effect of exogenous FSH on ovarian granulosa cells depend on endogenous FSH.  This study demonstrated that the FSH gene was expressed in chicken follicles and promoted ovarian granulosa cell proliferation, which enriched the theory on HPG axis.

Reticuloendotheliosis virus (REV) causes the atrophy of immune organs and immuno-suppression in chickens, but the underlying molecular mechanism of the immune response after infection by REV is not well understood.  Presently, the RNA-seq was used to analyze the regulation of immune response to REV in chicken lymphocytes from peripheral blood.  Overall, 134 differentially expressed long non-coding RNAs (lncRNAs) between cells with REV infection or without  in vitro were screened.  Based on the differentially expressed protein-coding genes, the nucleotide-binding oligomerization domain (NOD)-like receptor pathway related to immune regulation was enriched.  Two lncRNAs (L11530 and L09863) were predicted to target the NOD1 and tumor necrosis factor receptor-associated factor 5 (TRAF5) gene, respectively, which are involved in the NOD-like receptor pathway with cis-regulation way.  The in vitro results revealed the significantly up-regulated (P<0.01) levels of lncRNA-L11530 and its target gene, NOD1, and the significantly down-regulated (P<0.05) levels of lncRNA-L09863 and its target gene, TRAF5, in lymphocytes after REV infection.  These changes also occurred in vivo in blood lymphocytes of chickens infected with REV.  Further, L09863 and L11530 were respectively interfered, the expression levels of their target genes NOD1 or TRAF5 were significantly down-regulated, accompanied by the change of IL-8 and IL-18 secretions in lymphocytes.  The NOD-like receptor pathway appears to be important in the immune response to REV, LncRNA-11530 and lncRNA-09863 might involve in the immune regulation on REV infection by targeting NOD1 or TRAF5 in blood lymphocytes of chickens.  Our findings reveal a new regulation of lncRNAs (L11530 and L09863) on immunity in chicken peripheral blood lymphocytes for REV infection by changing the expression of the target genes via the NOD-like receptor pathway.