First Defense is a USDA Veterinary Biologic that provides guaranteed levels of protection against both bacterial and viral scours. A single dose of First Defense provides antibody-driven immediate immunity proven to reduce mortality and morbidity from scours caused by E.coli K99 and Coronavirus. First Defense is OMRI listed for organic operations. Administer along with colostrum immediately after birth. The First Defense line of products is available in three different delivery options: capsule, gel tube (with a non-digestible blue dye protocol marker), and powder (for colostrum administration).