Shiga toxin-producing E. coli, often referred to as STEC 0157 or simply E. coli, is naturally occurring in cattle and though it does no harm to the cattle, can make humans sick.
Though beef processors have implemented control steps to reduce the chances that beef leaving the plant is contaminated with the pathogen, another potential way to reduce prevalence of E. coli is to vaccinate cattle in feedlots before they are processed.
"Immunization through vaccination has been a commercially available pre-harvest intervention to reduce E. coli shedding in cattle for about five years," said agricultural economist Glynn Tonsor, who is a livestock marketing specialist with K-State Research and Extension. "Despite demonstrated substantial improvement in human health the vaccine offers, it has not been widely adopted."
In a recent study, Tonsor and K-State agricultural economist Ted Schroeder took a closer look at the potential economic impacts of incorporating animal vaccination into E. coli pre-harvest control practices.
The study found two primary reasons why feedlot managers don't use E. coli vaccines: There are no production costs for feedlots directly associated with the prevalence of E. coli, and there is no well-established market that compensates producers for vaccinating for the pathogen.
Generally, the price paid for cattle coming out of feedlots is the same whether the vaccine was used or not. Because there's no feeding efficiency benefit, and administering the vaccine adds costs without direct economic incentives, most cattle feeders choose not to, Tonsor said.
The study also found that in the current market, producer adoption of E. coli vaccination protocols is likely to remain limited. If such vaccinations were implemented, it would cost U.S. feedlots $1 billion to $1.8 billion in economic welfare loss over 10 years if demand didn't increase with premiums for vaccinated cattle.
Retail or export beef demand increases, however, could spur adoption by feedlot producers. Considering different scenarios, the study found that retail beef demand increases of 1.7% to 3% or export beef demand increases of 18.1% to 32.6% would be necessary to generate sufficiently higher fed cattle prices to offset the costs associated with vaccination.
Production cost decreases to either beef retailers or wholesalers could also provide an incentive for feedlot producers to vaccinate, the study said. Cost declines of 2.2% to 3.9% for retailers or alternatively production cost declines of 1.2% to 2.2% for packers would be necessary to generate sufficiently higher fed cattle prices to cover feedlot adoption costs, making producers economically neutral to adoption.
"A key point of this research is that limited use of E. coli vaccinations in U.S. feedlots is consistent with the lack of current economic signals for producers to expand adoption," Schroeder said. "Unless there is a substantial change in market signals presented to feedlot operators, limited use of E. coli vaccinations can be expected in the future."