In comparison with the external appearance, the physiology of pigs underwent insignificant changes. Among other pets, they stand out primarily for their omnivorousness. Pigs enjoy the same pleasure with root vegetables, fruits, vegetables, grain and mixed fodder, eggs, meat, fish, technical waste from oil mills and sugar refineries, any food scrap, from bread and skim (skim milk) to rotten products.
They have high food plasticity, so they easily adapt to the daily changing “home” diet, and to feed the same type of food. For example, in the old days, for pigs, no special feed mixtures were produced, but simply grazed them as cows and sheep. Especially intensively they were fattened in the autumn, when the harvest of acorns and nuts ripened. Since then, in many European countries, the custom to cut pigs in November has been preserved.
As for the population domesticated in the Far East, no prejudices prevented its spread. So, in China, Korea, Vietnam, some countries of Southeast Asia, pigs have become almost the main domestic animals. In Australia and Africa, pigs are relatively few, but only because they do not tolerate the dry climate. In total, there are about 1 billion of these animals in the world, they are inferior only to large cattle and sheep in terms of the number of livestock.