Effect of using frozen-thawed bovine semen contaminated with lumpy skin disease virus on in vitro embryo production

Cornelius Henry Annandale; Mario P Smuts; Karen Ebersohn; Lizette du Plessis; Peter N Thompson; Estelle H Venter; Tom A E Stout

doi:10.1111/tbed.13179

Effect of using frozen-thawed bovine semen contaminated with lumpy skin disease virus on in vitro embryo production

Transbound Emerg Dis. 2019 Jul;66(4):1539-1547. doi: 10.1111/tbed.13179. Epub 2019 Apr 7.

Authors

Cornelius Henry Annandale¹, Mario P Smuts¹, Karen Ebersohn², Lizette du Plessis³, Peter N Thompson¹, Estelle H Venter^{2

4}, Tom A E Stout^{1

5}

Affiliations

¹ Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
² Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
³ Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
⁴ School of Public Health, Medical and Veterinary Sciences, Discipline: Veterinary Science, James Cook University, Townsville, QLD, Australia.
⁵ Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.

PMID: 30892826
DOI: 10.1111/tbed.13179

Abstract

Lumpy skin disease (LSD) is an important transboundary animal disease of cattle with significant economic impact because of the implications for international trade in live animals and animal products. LSD is caused by a Capripoxvirus, LSD virus (LSDV), and results in extensive hide and udder damage, fever and pneumonia. LSDV can be shed in semen of infected bulls for prolonged periods and transmitted venereally to cows at high doses. This study examined the effects of LSDV in frozen-thawed semen on in vitro embryo production parameters, including viral status of media and resulting embryos. Bovine oocytes were harvested from abattoir-collected ovaries and split into three experimental groups. After maturation, the oocytes were fertilized in vitro with frozen-thawed semen spiked with a high (HD) or a lower (LD) dose of LSDV, or with LSDV-free semen (control). Following day 7 and day 8 blastocyst evaluation, PCR and virus isolation were performed on all embryonic structures. After completing sufficient replicates to reach 1,000 inseminated oocytes, further in vitro fertilization (IVF) runs were performed to provide material for electron microscopy (EM) and embryo washing procedures. Overall, in vitro embryo yield was significantly reduced by the presence of LSDV in frozen-thawed semen, irrespective of viral dose. When semen with a lower viral dose was used, significantly lower oocyte cleavage rates were observed. LSDV could be detected in fertilization media and all embryo structures, when higher doses of LSDV were present in the frozen-thawed semen used for IVF. Electron microscopy demonstrated LSDV virions inside blastocysts. Following the International Embryo Transfer Society washing procedure resulted in embryos free of viral DNA; however, this may be attributable to a sampling dilution effect and should be interpreted with caution. Further research is required to better quantify the risk of LSDV transmission via assisted reproductive procedures.

Keywords: bovine embryo; culture media; in vitro fertilization; lumpy skin disease virus.

MeSH terms

Animals
Blastocyst / virology
Cattle
Cryopreservation / veterinary
Culture Media
Embryo, Mammalian / virology*
Female
Fertilization in Vitro / veterinary
Lumpy Skin Disease / virology*
Lumpy skin disease virus / isolation & purification*
Male
Semen / virology*
Viral Load / veterinary

Substances

Culture Media