Interpretive Summary: Effect of combined maternal and post-hatch dietary 25-hydroxycholecalciferol supplementation on broiler chicken Pectoralis major muscle growth characteristics and satellite cell mitotic activity

By: Luis P Avila, Samuel F Leiva, Gerardo A Abascal-Ponciano, Joshua J Flees, Kelly M Sweeney, Jeanna L Wilson, Kathryn J Meloche, Bradley J Turner, Gilberto Litta, April M Waguespack-Levy, Anthony Pokoo-Aikins, Charles W Starkey, Jessica D Starkey

Skeletal muscle growth is largely dependent on the proliferation and differentiation of muscle-specific stem cells known as satellite cells (SC). Previous work has shown that dietary inclusion of the vitamin D3 metabolite, 25-hydroxycholecalciferol (25OHD3), also called calcidiol, can promote skeletal muscle growth in post-hatch broiler chickens. Improving vitamin D status of broiler breeder hens by feeding 25OHD3 in addition to vitamin D3 has also been shown to positively impact progeny. Yet, whether combined pre- and post-hatch supplementation with 25OHD3 produces an additive or synergistic SC-mediated, skeletal muscle growth response remains unanswered. The results of this study reveal that combined maternal and post-hatch 25OHD3 supplementation does not produce additive or synergistic effects on SC-mediated broiler muscle growth. However, vitamin D status improvement through dietary 25OHD3 inclusion in either the maternal or post-hatch diet stimulated broiler breast muscle growth by increasing proliferating SC populations. Overall, this work answers not only practical questions for the broiler industry regarding the possible benefits of combining maternal and post-hatch dietary 25OHD3 supplementation but also improves our understanding of vitamin D’s role in pre- and post-hatch broiler skeletal muscle growth.