At the input side of the chain, the feed industry plays a major role. Food safety demands have led to strict procedures for tracking and tracing. Not all food ingredients, especially some imported ones, like soy, can be fully traced back to origin, however. Feed companies also give advice to companies and often are brokers for so-called pig rights. Since about a decade now, the number of pigs in The Netherlands is limited to a fixed maximum. Whenever a farmer sells his business, the released pig rights will be sold to other farmers, often through these brokers. Feed companies may also play an integrating role between farrowing farms, finishers, and slaughterhouses, although this role is still limited.
German Association of Animal Nutrition (only in German)

There are also worries with respect to soy production. Soy is an important component of animal feed.

Links of the Adour Sanders Animal Nutrition in France wich provide feed for Bayonne Ham chain porcs