Interpretive Summary: Effects of in ovo injection of nicotinamide riboside on high-yield broiler myogenesis

By: Xiaoxing Xu, Hanna M Alcocer, Morgan E Gravely, Ashunti R Jackson, John M Gonzalez

Broiler chicken weight gain is a result of genetics and nutrition, with increased muscle mass attributed to accelerated embryonic myogenesis and posthatch muscle growth. During the avian incubation period, in ovo injection may be used as a strategy to deliver exogenous supplements into growing embryos for improving skeletal muscle development and growth. Nicotinamide riboside (NR), a vitamin B3 analog, is a human performance supplement used to stimulate mitochondria biogenesis and elevate tissue NAD+ levels. Research showed injecting NR into the chick embryonic yolk sac increased breast muscle weight and muscle satellite cell numbers and proliferation rate. Therefore, our objective was to determine the effects of in ovo injection of high-yield broilers with NR on broiler breast muscle development and growth. Our study showed in ovo injection of NR into the yolk sac increased hatched chick breast muscle morphometrics, which coincided with an increase in muscle fiber density and tended to decrease fiber cross-sectional area. Increased Sirtuin1 and cyclin D mRNA expression of hatched chicks from eggs injected with 2.5 mM NR into yolk sac indicate a potential NR regulated Sirtuin1/cyclin D molecular mechanism mediating chicken muscle early development.