MC4R and Anorexia: POMC, a precursor of α-MSH, lipotropins and β-endorphin, is one of the important factors in the hypothalamus suppressing appetite [62], and α-MSH, as a melanocortin agonist, can act on melanocortin receptors MC3R and MC4R in the poultry hypothalamus as an anorexia signal, thereby suppressing appetite and promoting energy consumption [56, 63].