The development of pig production started in the 1960s when the first group of exotic pigbreeds
was imported by the Department of Livestock Development from the United Kingdom.
These were Large White, Tamworth and Berkshire breeds. Later, Landrace and Duroc pigs were
imported from the United States [2]. Before these exotic breeds were introduced, farmers relied on
the relatively slow growing native pigs that had the desirable quality of not needing much in the
way of trade inputs [1]. Since 1981 pig breeding has steadily been industrialised in Thailand. Thus,
indigenous native pigs have been increasingly mated with imported breeds to improve their
performance in economically important traits. Native pigs have gradually become crossbreeds and are
finally replaced by European commercial breeds as the meat delivering end product in the pork
industry [7].