ABSTRACT Chicken abdominal fat (AF) is an economically important trait, and many studies have been conducted on genetic selection for AF. However, previous studies have focused on detecting functional chromosome mutations or regions using gene chips. The present study used the specific-locus amplified fragment sequencing (SLAF-seq) technology to perform a genome-wide association study (GWAS) on purebred Wengshang Barred chicken. A total of 1,286,715 single-nucleotide polymorphisms (SNPs) were detected, and 175,211 SNPs were selected as candidate SNPs for genome-wide association analysis using TASSEL general linear models. Two SNPs markers reached genome-wide significance. Of these, rs7943847, rs127627362 were significantly associated with AF at 120 days. These SNPs are close to eight genes (SLC16A6, ARSG, WIPI1, PRKAR1A, FAM20A, ABCA8, ABCA9, CPQ,). These results would enrich the studies on AF and promote the use of Chinese chicken, especially the Wenshang Barred chicken.

ABSTRACT The effects of plant essential oil (PEO) on the production performance and immune function of laying hens were evaluated to provide theoretical basis for promoting the natural plant extracts. Eight thousand 1-day-old healthy laying hens were randomly divided into a control group or PEO group, with four replicates per treatment and 1000 hens per replicate. The PEO diet was supplemented with 3g/kg plant extract. Diets were fed for 56 days. The tibia length and keel length were detected on an empty stomach at the end of the trial. Blood samples were collected on the 28th and 56th days to detect the level of C3, C4, IL-1, IL-2, IL-17 and immunoglobulin in the serum. The results showed that, compared with the control, PEO supplementation significantly increased the weight gain rate (WGR) at the 2nd, 4th, 5th and 7th week (p<0.05), and decreased the WGR at the 3rd and 6th week. The tibial length was significantly increased at the 3rd, 5th, 6th and 7th week (p<0.01), and also the keel length at the 5th and 7th week in PEO group. The concentration of IgG and IgM also significantly influenced with PEO supplementation, but there was no significant difference in the complements, C3 and C4, and the IL levels between days 28 and 56. Moreover, no significant difference was observed in body weight and immune organ on day 56. Therefore, we conclude that the addition of PEO could improve the production performance and immune function in laying hens.