Relationship between the prevalence of hepatic milk spots in pig and the egg density of Ascaris suum in Kitakyushu Municipal Meat Inspection and Control Center

Abstract

The hepatic milk spots of pigs are chronic interstitial hepatitis, and are caused by the migration of pig ascarid worm, Ascaris suum, into the liver. A large number of livers are condemned in meat inspection centers as defective food once they are found to have developed milk spots, and thus the economic loss is great. Eggs of Ascaris suum from 120 caecum feces of slaughtered pigs were detected by the nylon mesh filtration (Makiya) technique and they were related to the condemnation data of the milk spot livers in Kitakyushu Municipal Meat Inspection and Control Center from April 2000 to February 2001. The condemnation rate was continuously more than 50% at some particular pig farms, the average rate being as high as 73% during this period. Liver milk spots and Ascarid infection from some 200 mg of caecum feces sampled with the template of the filtration technique were compared. As a result, a close agreement was observed between the two kinds of positive data, and a significant correlation was expected between the average egg density (EPG) of sampled pigs and the prevalence rate of milk spots of the same groups. These results proved that this filtration technique can be used as an effective inspection method for detecting milk spot liver.