BOAR SEMEN - A POTENTIAL RISK FACTOR IN THE INFECTIOUS CYCLE OF THE PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME

Based on an experimental study using two and six PRRS-negative young b oars and gifts, respectively, it was proven wether boar semen could be a risk factor in the transmission of the disease. The two boars were inoculated intranasally with the PRRS-virus strain l10 (Intervet) cont aining 107 TClD50/ml. Using ovulation synchronization six gilts were p repared as bioindicators to be inseminated, two of them with semen of the two boars at day 4, 8 and 12 after infection. Following inoculatio n of the boars, PRRS virus was shown to be present in blood from the 2 nd until the 35th and 40th day p.i., respectively. PRRS virus could al so be isolated from nasal swabs at day 6, 9, 12 and 19 and from preput ial swabs at day 4, 12 and 27 after infection. PRRS virus could only b e detected at day 19 p.i. in semen of one boar. Drastic changes in qua lity and volume of the ejaculate were oberserved about day 25 p.i. in both animals. Insemination of the gifts with semen collected at day 4, 8 and 12 p.i., however, did not lead to an infection of the females, because neither clinical signs typical for PRRS nor seroconversion cou ld be observed. Reproductive parameters as well as birth and growing t raits of the gilts were in accordance with norm values.