OBSERVATIONS ON ENDEMIC COURSE OF PARVOVI RUS INFECTION IN HIGHLY CONCENTRATED PIG BREEDING STOCK

An account is given in this paper of studies into parvovirus antibody titres in sows prior to and after pregnancy in a stock affected by the chronic-endemic form of parvovirosis. Both titre levels prior to inse mination as well as titre dynamics during gravidity exhibited correlat ions with subsequent fertility and litter results, although such corre lations were clearly pronounced only in gilts. Hence, the conclusion i s drawn that growing frequency of pregnancies is accompanied by activa tion of defence mechanisms which are not correlated With antibody titr e levels.