Bovine leukemia virus (BLV) is a retrovirus of cattle that infects approximately 45% of all US dairy cattle. with about 90% of US dairy herds having at least one infected animal. Studies have found BLV infection to be associated with multiple measures of decreased immune function. which may explain the observed economic losses from milk production. https://www.crochetandknitshop.com/product-category/supplements/