What is BLV and Why do we Care? 

Bovine Leukemia Virus

Bovine leukemia virus (BLV) is a retrovirus that affects both dairy and beef cattle, and causes enzootic bovine leukosis. 

For a great podcast from the MSU Extension Dairy team, listen here!


Introduction to BLV & Retroviruses, Created by Lauren Eichberger and Presented by Dr. Tasia Kendrick

Impact on the Economy & Animal Productivity

Did you know? Annual economic losses to the US dairy industry due to BLV have been estimated to be $285 million for producers and $240 million for consumers (32). 

Countries may have import and export restrictions based on BLV status. New Zealand and Australia will only import/export BLV-free milk. Many European countries have strict policies on the import/export of embryos dependent on BLV status. 

In addition to the economic impacts of BLV, there are potential animal welfare and productivity. BLV has been demonstrated to:

  • Decrease milk production
  • Decrease cow welfare and longevity
  • Increase slaughter condemnation.