Thai food is known for its enthusiastic use of fresh (rather than dried) herbs and spices. Common flavors in Thai food come from garlic, galangal, coriander/cilantro, lemon grass, shallots, pepper, kaffir lime leaves, shrimp paste, fish sauce, and chilies. Palm sugar, made from the sap of certain Borassus palms, is used to sweeten dishes while lime and tamarind contribute sour notes. Meats used in Thai cuisine are usually pork and chicken, and also duck, beef, and water buffalo. Goat and mutton are rarely eaten except by Muslim Thais. Game, such as wild boar, deer and wild birds, are now less common due to loss of habitat, the introduction of modern methods of intensive animal farming in the 1960s, and the rise of agribusinesses, such as Thai Charoen Pokphand Foods, in the 1980s.[27] Traditionally, fish, crustaceans, and shellfish play an important role in the diet of Thai people.[28] Anna Leonowens (of The King and I fame) observed in her book The English Governess at the Siamese Court (1870):[29]