Genetic parameters of feeding behavior traits and multi-tissue transcriptomic comparison of divergent feeding patterns in ducks.

Feeding behavior is a key factor influencing growth performance and feed efficiency in poultry, yet its complex phenotypes remain difficult to quantify accurately, limiting the application of large-scale behavioral data in genetic and molecular analyses. In this study, feeding behavior and feed efficiency-related phenotypes were recorded in 829 Tianfu Nonghua ducks using an automated feeding monitoring system integrated with radio frequency identification (RFID) technology. Genetic parameter estimation indicated that the heritability of feeding behavior traits ranged from 0.25 to 0.39. Individuals were classified into high-frequency feeding (HFF) and low-frequency feeding (LFF) groups. Phenotypic analysis showed that ducks in the HFF group had significantly higher residual feed intake (RFI) and feed conversion ratio (FCR) than those in the LFF group. Based on this grouping, transcriptome sequencing was performed on the hypothalamus, pituitary, and liver tissues. A total of 266, 181, and 94 differentially expressed genes (DEGs) were identified in the three tissues, respectively. Enrichment analysis highlighted tissue-specific pathways, including neuroactive ligand-receptor interaction and calcium signaling in the hypothalamus, the Apelin signaling pathway in the pituitary, and steroid hormone biosynthesis in the liver. Appetite-related genes in the hypothalamus (PMCH, HCRT, and CCKAR) and endocrine and metabolic genes in the pituitary and liver (TRH and NEGR1) showed differential expression between feeding strategies. Weighted gene co-expression network analysis further identified hub genes (ITPKB, BAMBI, and BCKDHB) associated with total feeding bouts (TFB). These findings provide new insights into the genetic architecture of feeding behavior traits and the molecular differences associated with divergent feeding patterns in ducks.