I wrote this in responce to a request about a NM study that showed no difference when PIs were in a feedlot pen. I thought it was worth sharing.
We (Animal Profiling) have always focused on finding and eliminating BVD PIs at the ranch. I have seen the study and others that do not support testing at feedlot arrival. I have also worked with yards that have data to support testing. We have seen that there are a lot of dynamics that are difficult to repeat in a study and do a large enough study to determine significance. All PIs are not equal and they do shed at varying levels. Previous vaccination, metaphylactic antibiotics, commingling and source all can effect the outcome. Bottom line we feel is that BVD is bad for the cattle industry and the PI is the continued source/reservoir for the virus.
I continue to ask the feeding industry to help us identify PIs through what we call our surveillance program not by testing all incoming cattle. That is simply looking for PIs in the deads. This helps us identify a problem source and make a difference on the farm or ranch by testing and eliminating the PIs along with improving their vaccination and biosecurity awareness. Many feedyards are not able to determine ranch origin, but finding them still identifies problem buyers and possibly salebarns. With this info we can then educate the cowcalf operation that there is a problem and we can control it through testing, vaccination and making sure that purchased bulls and heifers are tested PI negative.
The key is proper education and awareness regarding PIs. We are testing in over 30 states primarily with cow calf operations and dairies. I believe we need the feedyard support, but not in the form of testing all incoming. As a veterinarian with feedyard experience, I like the fact that I can identify a PI and know that it was a ranch problem and we did not cause it at the feedyard. Too many times the person I was talking to that was upset with the deathloss thought that the feedyard caused the dead. This is one condition that I can say you have a problem and offer to figure out a way that we can help to solve it. One feedyard recently said that PIs were 11% of their deathloss.
There is not one way that we as an industry are going to solve the BVD problem, it will take an effort by the several sectors. As I travel around the country doing meetings, I am convinced that we are making a difference.