The pig holdings in Swabia, Germany, that were temporarily closed after the discovery of the antibiotic chloramphenicol in animal feed, have since been opened.
The investigation of the prosecuter against the perpetrators of Memmingen Allgäu dairy is still ongoing. At the firm a human error is supposed to have led to the contaminated feed.
As a spokesman for the prosecutor said this week, it will examine whether intentional misconduct has taken place.
At the end of January, the authorities had found residues of the banned antibiotic chloramphenicol in urine of pigs for slaughter and by way of precaution 26 pig farms in Bavaria and in the Ulm region were locked.
As a result 11,900 pigs from nine farms could then not be slaughtered normally, since products from these animals are not allowed to enter the food chain.
The cause of the feed contamination was improperly disposed laboratory waste. The antibiotic ended up in the so-called white water. This liquid that accumulates in the production of dairy and still contains milk ingredients is collected mainly by pig farms free of charge and added to the animal feed.
The dairy is not using chloramphenicol anymore since the incident.