Nested polymerase chain reaction detection and duration of porcine circovirus type 2 in semen with sperm morphological analysis from naturally infected boars

Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada.

A nested polymerase chain reaction (nPCR) protocol was applied to porcine semen to demonstrate the porcine circovirus type 2 (PCV2) shedding patterns and duration in naturally infected boars. Sperm morphology analysis was performed on a subset of samples to determine if the presence of PCV2 DNA in semen was associated with reduced semen quality. Semen was collected serially from 43 boars representing 6 breeds, aged 33.9 to 149.3 weeks. Of the 903 semen samples collected, 30 samples (3.3%) were positive for PCV2 DNA by nPCR from 13 boars. Boars shedding PCV2 DNA in semen ranged between 35.9 and 71.0 weeks of age, and shedding occurred during a period of up to 27.3 weeks. A semen nPCR test was 2.6 times more likely to be positive when collected from pigs that were < or =52 weeks of age, and 3.0 times more likely to be positive when collected from pigs that were < or =26 weeks from time of entry into the stud main unit (generalized estimating equations: P = 0.02; 95% confidence interval [CI] of the odds ratio 1.2 to 5.5, and P = 0.01; 95% CI of the odds ratio 1.3 to 6.9, respectively). These results demonstrate a sporadic and long-term shedding pattern of PCV2 DNA in semen from naturally infected boars. PCV2 DNA in semen does not appear to have detrimental effects on sperm morphology; however, boar age and, possibly, breed may contribute to the persistence of PCV2-shedding in semen.

This article has been cited by other articles:

				C. Firth, M. A. Charleston, S. Duffy, B. Shapiro, and E. C. Holmes Insights into the Evolutionary History of an Emerging Livestock Pathogen: Porcine Circovirus 2 J. Virol., December 15, 2009; 83(24): 12813 - 12821. [Abstract] [Full Text] [PDF]

				D. M. Madson, A. R. Patterson, S. Ramamoorthy, N. Pal, X. J. Meng, and T. Opriessnig Reproductive Failure Experimentally Induced in Sows via Artificial Insemination with Semen Spiked with Porcine Circovirus Type 2 Vet. Pathol., July 1, 2009; 46(4): 707 - 716. [Abstract] [Full Text] [PDF]

				D. M. Madson, A. R. Patterson, S. Ramamoorthy, N. Pal, X. J. Meng, and T. Opriessnig Effect of Porcine Circovirus Type 2 (PCV2) Vaccination of the Dam on PCV2 Replication In Utero Clin. Vaccine Immunol., June 1, 2009; 16(6): 830 - 834. [Abstract] [Full Text] [PDF]

				T. Opriessnig, A. R. Patterson, D. M. Madson, N. Pal, M. Rothschild, D. Kuhar, J. K. Lunney, N. M. Juhan, X. J. Meng, and P. G. Halbur Difference in severity of porcine circovirus type two-induced pathological lesions between Landrace and Pietrain pigs J Anim Sci, May 1, 2009; 87(5): 1582 - 1590. [Abstract] [Full Text] [PDF]

				D. M. Madson, S. Ramamoorthy, C. Kuster, N. Pal, X.-J. Meng, P. G. Halbur, and T. Opriessnig Characterization of shedding patterns of Porcine circovirus types 2a and 2b in experimentally inoculated mature boars J Vet Diagn Invest, November 1, 2008; 20(6): 725 - 734. [Abstract] [Full Text] [PDF]

				K. S. Lyoo, H. B. Kim, and H. S. Joo Evaluation of a nested polymerase chain reaction assay to differentiate between two genotypes of Porcine circovirus-2 J Vet Diagn Invest, May 1, 2008; 20(3): 283 - 288. [Abstract] [Full Text] [PDF]

				T. Opriessnig, X.-J. Meng, and P. G. Halbur Porcine Circovirus Type 2 associated disease: Update on current terminology, clinical manifestations, pathogenesis, diagnosis, and intervention strategies J Vet Diagn Invest, November 1, 2007; 19(6): 591 - 615. [Abstract] [Full Text] [PDF]