Field studies with in-feed medication of pigs in the Netherlands using the anthelmintic thiophanate with particular reference to efficacy against Ascaris suum.

Studies on the efficacy in pigs of low level in-feed medication with the anthelmintic thiophanate at a minimum intake of 6 mg/kg/day for fourteen days are reported. A trial was conducted to compare a group of medicated fattening pigs with a similar unmedicated group on premises known to have a high challenge of Ascaris spp. Daily growth rate was improved whilst feed conversion ratio and the liver condemnation rate were reduced in the treatment group. Routine medication of a whole herd using this regime contributed to a great improvement of the herd production when assessed by the above criteria. User studies in various geographical areas of the Netherlands involving 1500 adult pigs and 1200 fattening pigs medicated with thiophanate in-feed for fourteen days demonstrated that the compound eliminated the faecal worm egg output and was readily accepted and tolerated by pigs.