- Tesseraud S, Metayer S, Duchêne S, Bigot K, Grizard J, Dupont J. Regulation of protein metabolism by insulin: value of different approaches and animal models. Domest Anim Endocrinol. 2007;33:123-42 pubmed..Finally, although the role of insulin has been doubtful and has long been considered to be minor in ruminants and in avian species, this hormone clearly regulates protein metabolism in both species. ..