Numerous factors come into play when evaluating benefits and payback on new mastitis prevention tool.
Numerous factors come into play when evaluating benefits and payback on new mastitis prevention tool.

Imrestor, Elanco Animal Health’s new mastitis prevention tool, came to the market this month. It claims to reduce clinical mastitis in the first 30 days after calving. The questions on the minds of producers: Will it work? How well? And will it pay?

Elanco sponsored seven producer meetings in key dairy areas across the country in April, introducing the product and reporting the results of its trial to prove product efficacy. In the five-herd commercial trial involving 800 total cows, Imrestor reduced mastitis 28% in the first 30 days after calving. The rate of clinical mastitis in the control cows was 25%; the rate of clinical mastitis in cows treated with two doses of Imrestor was 18%.

The key question, then, is what clinical mastitis costs in the first 30 days after calving. In a study published this past fall in the Journal of Dairy Science done at the University of Georgia and co-authored by Mike Overton, an Elanco veterinarian, the estimated total cost of one case of mastitis was $444. That included $128 in direct costs (diagnostics, therapeutics, non-saleable milk, veterinary, labor and death loss). The indirect costs were $316 (future milk production loss, premature culling and replacement loss, and future reproductive loss). The estimates were based on current prices at the time of the study for milk ($21 per cwt), feed (13¢ per pound of dry matter) and dairy replacements ($2,094 per head).

  • Whether Imrestor pays for itself depends on:
  • What a dairy farmer has to pay for the product
  • Whether he or she sees a 28% reduction in mastitis or, more or less, in the first 30 days after calving
  • How much milk, feed and replacements cost

If, as in the Elanco FDA trial, the herd sees seven fewer cases of clinical mastitis for every 100 cows in the herd, the savings would be about $3,100. So the break-even price on treatment of 100 cows would be about $30 per cow.

Again, that will obviously vary depending on costs, conditions and mastitis rates in individual herds. “You’ll need to use records to evaluate effectiveness and response in your animals,” says Paul Rapnicki, a veterinarian and a dairy technical consultant with Elanco.

How Imrestor works

A cow’s immunity is suppressed around the time of calving, therefore she becomes more susceptible to disease, particularly mastitis. Imrestor helps bolster immunity by restoring the function and increase the number of bacteria-killing neutrophils in the cow’s blood stream. If a mastitis infection occurs, these neutrophils migrate into the udder to kill the mastitis causing bacteria. In the trials, Imrestor was effective against all types of mastitis. (Somatic cell counts in milk are not increased unless mastitis occurs.)

The product is given twice subcutaneously. The first time should be administered seven days before anticipated calving (four to 10 days prior to the cow’s due date to accommodate management routines) and again within 24 hours after calving.

At the Sioux Falls meeting, one farmer asked if one shot of Imrestor would work. “The two-dose Imrestor regimen is important to follow because the window of vulnerability due to periparturient immune suppression starts at least a week before calving and lasts two to three weeks into calving,” Rapnicki explains. “If you only give one injection, you are not able to help restore the innate immune system for the entire period of vulnerability. In accordance with label direction, a producer should always administer two doses of Imrestor.”

Imrestor is not an antibiotic, hormone or vaccine. Rather, it is an immune restorative protein classified by the Food and Drug Administration (FDA) as an immunomodulator (pegbovigrastim injection). Consequently, the FDA is requiring it be sold through veterinarians because it is a prescription, biotherapeutic protein.

Imrestor should not be used to treat mastitis once it occurs because effectiveness has not been demonstrated for this use. No milk or meat withdrawal is needed if given according to label directions.

Veterinarians will set the retail price for Imrestor. Elanco is offering a 30% price discount for the first six months after its introduction.