We often hear that mastitis costs the U.S. dairy industry $2 billion per year. But what does this mean on a case level? The average cost of a mastitis case is around $250. However, this estimate also has a wide range. Depending on the study, the cost estimates for mastitis vary from less than $5 to more than $450 per case. Such highly variable estimates can make decisions regarding mastitis difficult. Because mastitis is a complex disease, costs should be considered on a case-by-case basis. Understanding both the direct and indirect or hidden costs will help in making better mastitis management decisions.
Direct costs
Direct costs include expenses for which money can be tracked as it leaves the farm, such as treatment costs, discarded milk and veterinary expenses. These costs heavily depend on the mastitis cases, but management standard operating procedures (SOPs) can significantly influence the total cost.
Treatment costs
Total treatment costs include the expense of the antimicrobial and discarded milk. Non-salable or discarded milk is the most significant direct cost of mastitis. Although still not widely adopted, milk cultures can help guide treatment choices, leading to more cost-effective treatments. Often, mastitis cases are treated based solely on clinical signs. As a result, treatments may be given when they are not actually needed.
Treatment success largely depends on the bacteria causing the intramammary infection. The cow's immune system often naturally cures mastitis caused by gram-negative bacteria. However, research supports treating cases caused by gram-positive bacteria according to label recommendations. These recommendations may vary in dosage and duration. Research indicates that the minimum dose and duration are effective in treating most mild to moderate cases of mastitis.
Since duration affects the number of doses and milk withdrawal, it can significantly influence the overall cost of a mastitis case. Research from Michigan State University demonstrated that farms could reduce their mastitis treatment costs by 40% by cutting treatment duration from five days to two days. In the example scenario, the farm saved $74,000 in treatment expenses for the same number of mastitis cases.
Since milk discard accounts for most treatment costs, reducing treatment duration can save money by decreasing the amount of milk dumped down the drain. For instance, a cow producing 80 pounds of milk daily, with a milk price of $18 per hundredweight results in $14.40 daily in discarded milk. Cutting treatment time from five days to two days can lower the cost of this single case by $43.20. Although these savings may seem small for a single case, applying a five-day treatment across the entire herd can lead to significant savings.Veterinary costs
When evaluating research on mastitis costs, veterinary expenses are among the most variable factors. This variability stems from inconsistencies in cases that require veterinary treatment. While most mastitis cases can be managed by farm staff, some do need veterinary care. As a result, most studies account for the likelihood of veterinary intervention when estimating the cost of a mastitis case.
Indirect costs
Indirect costs are expenses that aren't immediately visible on the farm. Because these costs are often unseen, they are more challenging to estimate in mastitis cases. We usually depend on research estimates in such situations. Indirect costs include poor reproductive performance, early culling and decreased milk production. The timing of the infection significantly affects the indirect costs associated with mastitis.
Reproductive performance
One of the simplest ways to estimate the economic impact of reproductive performance is by considering additional days open caused by a disease. Research estimates that each extra day open costs about $2. However, conflicting research exists regarding the impact of mastitis on days open. Consistent findings show that mastitis cases negatively influence pregnancy and conception rates. Cows with mastitis around the time of breeding experience the most significant impact on reproductive performance. Overall, studies estimate that up to $90 of the total cost of mastitis can be attributed to decreased reproductive performance.
Early culling
According to USDA data, about 25% of culling decisions are due to mastitis. When calculating mastitis costs, culling is included because of the possibility that the cow may be removed from the herd. This probability contributes to the high variability in estimates of mastitis costs. Estimating the cow's value can be very challenging. Simply taking the difference between the slaughter value and the cost of a replacement can underestimate the cow's actual value.
The most accurate way to evaluate a cow’s worth is by comparing her future profit potential to that of her replacement within a specific time frame. This value is known as the retention payoff. A positive retention payoff means the cow still has more value than her replacement. Any positive value should be added to the cost of the mastitis case. The retention payoff is mainly affected by days in milk, milk production and pregnancy status. Therefore, the timing of the mastitis infection can influence the cow’s value.
Milk production loss
Loss of future milk production is the most significant cost associated with a case of mastitis. Like other indirect costs, milk yield loss depends on when the infection occurs. Historical data indicate that infections occurring during the transition period or early lactation result in greater loss of milk production than those that arise after peak milk yield. However, research from the past five years indicates that not only do infections in early lactation significantly reduce milk production, but infections in late lactation do as well.
Cows that experience their first mastitis infection during the transition period or early lactation produce 6% to 8% less milk than their healthy herdmates. First infections late in lactation lead to 5% to 10% less milk production. The lost milk yield can amount to $180 to $360 of the total cost of a case of mastitis.
Overall, the duration and timing of infection treatment can significantly influence the total cost of a mastitis case. Duration impacts how much milk and revenue are lost, while timing affects future milk production. Recent research shows that milk production losses are similar across all lactation stages when comparing infected cows to healthy ones. To save money, follow label recommendations for the minimum treatment duration and only extend treatment with a veterinarian's advice for severe cases. Remember that a clinical cure is distinct from a biological cure. Just because the milk still looks abnormal does not mean bacteria are still present. Culturing can help guide more precise treatment decisions.
