BVDV Testing Strategy Guide—BeefTest With Confidence™ U.S. veterinarians estimate that bovine viral diarrhea virus (BVDV) costs producers more than $30 per head each year in lost productivity, even after vaccination.1 Fortunately, with an effective management strategy and the right diagnostic tools, BVDV can be controlled. IDEXX recommends this 3-step strategy for BVDV control: 1. Determine your herd status using the IDEXX BVDV PI X2 Test at a local laboratory. 2. Test all new introductions to the herd using the IDEXX SNAP® BVD Test. 3. Work with your veterinarian to design a vaccination and biosecurity program. PI (Persistently Infected) An animal infected before birth that remains infected for life and can continually infect other cattle. TI (Transiently Infected) An exposed animal whose system eventually fights off the virus. Infection lasts several days to a few weeks and makes the animal susceptible to other diseases. Cow/Calf Ranches and Seed Stock/Purebred Breeders Maximum Protection Strategy Before breeding season: • Determine herd status by testing all: - Calves (If calf is negative, dam is negative. No need to test dam.) - Cows of positive calves (If calf can’t be traced to cow, consider testing all cows.) - Open cows and bulls • Test all new introductions, including replacement heifers, bulls and stockers. • Test all seed stock/purebred bulls and heifers offered for sale. • Develop a vaccination and biosecurity program with your veterinarian. • Keep vulnerable cattle (especially pregnant cows and those of uncertain testing status) away from fence-line contact with untested cattle. • Test annually using the Surveillance/Maintenance Strategy and/ or continue to test each calf crop. (Note: Pl-tested calves bring added value.) Surveillance/Maintenance Strategy • Test all: - New introductions - Aborted fetuses and calves that die - Animals treated for bovine respiratory disease (BRD) and/or other illnesses • If a PI animal is detected, implement the Maximum Protection Strategy. Stocker/Backgrounder/Feedyard Maximum Protection Strategy • Determine herd status and test new introductions by: - Purchasing BVDV-PI-tested cattle. - Testing all calves with unknown PI status on or before arrival. • Develop a vaccination and biosecurity program with your veterinarian. Medium Protection Strategy • On or before arrival, test all high-risk calves with unknown PI status. • Follow the Surveillance/Maintenance Strategy for all other cattle. • Develop a vaccination and biosecurity program with your veterinarian. Surveillance/Maintenance Strategy • Test all: - Animals treated for BRD or other illnesses and cattle that die. This may identify pens/pastures with additional PI animals that need to be tested. - Cattle in problem pens/pastures with an unusually high sickness rate. If no PI animal is found, consider testing cattle in adjacent pens/pastures. Fence-line contact with a PI animal may be the source of infection. • If a PI animal is detected, test all cattle in that pen or pasture and consider implementing the Maximum or Medium Protection Strategy. 1. Data on file at IDEXX Laboratories, Inc. Westbrook,

BVDV Testing Strategy Guide—Beef Understanding How a PI Calf Is Created Is Key to Developing a BVDV Control Strategy Less common route (Less than 10%) BVDV persistently infected (PI) female becomes pregnant More common route (More than 90%) Susceptible pregnant female (non-PI) infected with BVDV at about 1½–4 months of gestation BVDV virus from any source PI calf BVDV persistently Infected (PI) calf is produced MYTH: BVDV won’t affect vaccinated cattle. FACT: he tremendous amount of virus secreted by a PI calf can T overwhelm a level of immunity that is protective under less severe exposure....