When a third or more of a rancher’s cows turn up open, which can happen when trichomoniasis, or trich, infects a herd, the rancher obviously takes a significant economic loss. But due to the sporadic nature of the disease, quantifying losses the disease causes across a region or across the country presents a challenge.

Texas A&M University economist David Anderson, PhD, recently presented his economic estimates of trich losses during a meeting of the NCBA BVD Working Group at the Cattle Industry Summer Conference. Anderson worked with university veterinarians to develop a set of assumptions and calculate the annual losses across the Texas cow-calf sector attributable to trich. He estimates that 20 percent of the 150,000 beef herds in Texas have some degree of trich infection in any year. Based on research, he used an average calving rate of 85 percent for the 80 percent of herds that do not have trich and a 73 percent calving rate for herds that do have it.

For this model, he based the estimates on a 90-day calving season. When cows are exposed to trich from bulls during breeding, they often conceive but lose the fetus 50 to 80 days into gestation. Over time, cows typically clear the infection and return to near-normal fertility in two to five months. So, with a 90-day breeding season, trich-infected cows probably will be open at the end of breeding. A longer breeding season could increase calving rate, but late calves would be much lighter at weaning, also resulting in financial losses.

Based on Anderson’s assumptions, trich could be reducing annual calf production in Texas by 2.5 percent, or 96,000 calves. Using 2013 averages, the lost revenue for those calves would be $95 million. At the finishing level, the lost value for those 96,000 missing calves is another $156 million.

He also applied his model to an actual ranch using historical data from Texas A&M’s Agriculture and Food Policy Center. Anderson selected a 335-cow operation and examined the impact of a 73 percent calving rate versus 85 percent.  The model shows the loss of 40 calves at a 73 percent calving rate would result in a reduction of $44,000 in net farm revenue, and because the farm would have invested in maintaining the cows and all other associated costs, that loss represents an 81 percent reduction in net farm revenue, which clearly would not be sustainable for the business over time.