Domestication and Feed Restriction Programming Organ Index, Dopamine, and Hippocampal Transcriptome Profile in Chickens.

The domestication process exerts different phenotypic plasticity between slow- and fast-growing breeds of chicken. Feed restriction has a critical role in production performance, physiological plasticity, and stress response. Our study aimed to explore how feed restriction programed the organ index, dopamine, and hippocampal transcriptome profile between slow- and fast-growing chickens, which were fed either (SA and FA), or feed restricted to 70% of (SR and FR), for 30 days. Results showed that feed restriction influenced the brain organ index ( < 0.05), but not the organ index of the heart, liver, and spleen. The slow-growing breed tested had a higher brain organ index than the fast-growing breed ( < 0.05). Under feed restriction conditions, both the slow- and fast-growing breeds had significantly elevated dopamine concentrations ( < 0.05) compared to those fed . In the GO term, upregulated genes in the FA group were enriched in the mitochondria, respiratory chain, and energy metabolism compared to the SA group ( < 0.05). Membranes and ribosomes were enriched in the cellular component between the SR and FR groups ( < 0.05). In the KEGG functional pathways, upregulated DEGs in the FR group were enriched in the cardiovascular disease category and neurodegenerative disease category compared to the FA group ( < 0.05). Downregulated DEGs in the FA group were enriched in the oxidative phosphorylation and neurodegenerative disease categories (Parkinson's disease and Huntington's disease) compared with the SA group ( < 0.05). Upregulated DEGs in the FR group were enriched in the cardiovascular disease category, neurodegenerative disease category, and energy metabolism than the SR group ( < 0.05). In conclusion, feed restriction had profound effects on the brain organ index and plasma dopamine in the slow- and fast-growing chickens. Feed restriction may result in issues relating to cardiovascular and neurodegenerative diseases in the fast-growing breed tested, but not in the slow-growing breed.