Li Shizhen's Compendium of Materia Medica contains the following records:
"Nameless" pigs, dolphins, Canada (referring to boars) and volunteers (referring to sows).
"Smell" pork: sour, cold and nontoxic (ordinary pork: bitter, slightly cold and slightly toxic. ) Lard: sweet, slightly cold and non-toxic. Pig liver: bitter in taste, warm in nature and nontoxic.
Chicken is warm, helps fire, and is not suitable for people with hyperactivity of liver yang, oral erosion, skin furuncle and constipation.