Jejunal Transcriptomic Profiling for Differences in Feed Conversion Ratio in Slow-Growing Chickens

Slow-growing Korat chicken (KR) is an alternative to broiler chickens that has been used as a national tool to support smallholder farmers due to a higher selling price of KR meat. However, the individual variability of feed efficiency (FE) within a KR stockbreeding results in a lack of competitiveness. Therefore, improvement of FE of KR is of major importance to improve the profitability of livestock production enterprises. Here, we selected two groups of KR with divergent feed conversion ratios (FCR). We performed RNA-sequencing in order to profile KR jejunal transcriptome and to identify the transcriptional variations and biological pathways implied in response to divergent FCR. The biological pathways involved were revealed by enrichment of the Gene Ontology (GO) terms, and the Kyoto Encyclopedia of Gene and Genome (KEGG) pathways. The results showed that main pathways involved in KR FCR divergence were related to immune response, glutathione metabolism, vitamin transport and metabolism, lipid metabolism, and maturation, development and growth. This is the first study to investigate the molecular genetic mechanisms affecting the FCR values in jejunum of slow-growing chicken. This study will be useful in the line-breeding programs for slow growing chickens to improve FE in the stockbreeding and its profitability. Jejunal samples of six KR were collected with extremely low FCR (n = 3) and high FCR (n = 3) and differentially expressed genes were identifiled using RNA-sequencing.