Embryo transfer from cattle infected with bluetongue virus

Area of Science:

• Veterinary Virology
• Reproductive Biology
• Embryo Transfer Technology

Background:

• Bluetongue virus (BTV) is a re-emerging pathogen affecting livestock.
• Concerns exist regarding potential BTV transmission through cattle embryo transfer.

Purpose of the Study:

• To evaluate the risk of bluetongue virus transmission during cattle embryo transfer.
• To determine if BTV can be transmitted from viremic donors to recipients via embryos.

Main Methods:

• Embryos were collected nonsurgically from BTV-viremic cattle donors.
• Embryos were surgically transferred to seronegative recipients.
• Virus isolation attempts were made from donor uterine fluids, recipient blood, and embryos.
• Immunofluorescence was used to detect virus antigen in embryos and oocytes.

Main Results:

• BTV was isolated from 11 of 20 donor uterine flushes, confirming viremia.
• BTV was not detected in any recipient blood or embryos.
• No recipient seroconverted, and pregnancy rates were not affected.
• Virus antigen was absent in all tested embryos and oocytes.

Conclusions:

• Standard cattle embryo transfer procedures are unlikely to transmit bluetongue virus.
• Nonsurgical embryo recovery and transfer do not appear to pose a significant risk for BTV spread.
• This study supports the safety of embryo transfer in BTV-endemic regions.