Studies on the IBR-IPV virus in the semen of insemination bulls
Goffaux, M.; Harlay, T.; Allietta, M.
Deutsche Tierärztliche Wochenschrift 83(12): 544-547
1976
ISSN/ISBN: 0341-6593 PMID: 187400 Document Number: 103007
Frozen semen from serologically positive AI bulls was checked for IBR-IPV virus in two AI Stations A and B. Semen from A was collected at the earliest 11/2 years after clinical findings, while that from B originated in a period of serum conversion. In Station A, 0.9% of the semen doses and 1.4% of the ejaculates were found to be contaminated. Forty-four serologically negative cows were inseminated with the most contaminated ejaculate from A (32 TCID50/doses) without any effect on their serological status or non-return rate. In Station B, 12% of the straws and 20% of the ejaculates were found to be contaminated. The mean titre was 14 TCID50 per straw. 30% of the positive ejaculates had titres below 2 TCID50, but in a further 19% the virus was found in amounts above 200 TCID50 per straw and one ejaculate reached a titre of 66 000 TCID50. Possible causes of large variations observed among results of repeatedly checked or titrated ejaculates were investigated.