The economic impact of cattle mastitis on Dairy Farms

Mastitis, an inflammation of the mammary glands caused primarily by bacterial infection, remains one of the most significant diseases in the dairy industry. This condition not only adversely affects the health and welfare of dairy cows but also results in considerable economic losses for dairy farmers. Worldwide, the cost of mastitis is estimated at €16-26 billion per year¹. The financial impact of cattle mastitis arises from multiple factors, including the cost of treatment, reduction in milk production, discarded milk due to treatment withdrawal periods, and the long-term effects of premature culling.

Treatment costs and decrease in milk production

Cattle mastitis leads to a direct economic burden on dairy farms through increased treatment costs and a decline in milk production. The immediate treatment of clinical mastitis typically involves the administration of antibiotics, anti-inflammatory drugs, and sometimes even more intensive care for severe infections. Treatment costs vary depending on the severity of the infection and the number of interventions required. The variation in cost is primarily dependent on the stage and severity of the infection, the drugs used, and the labor required for care.

Beyond treatment, mastitis significantly affects milk production, both in the short and long term². The most notable effect of clinical mastitis is a sharp reduction in milk yield. In addition to this, subclinical mastitis, characterized by elevated somatic cell counts (SCC) but no visible clinical symptoms, also reduces milk yield³.

Cattle mastitis leads to wasted milk

In addition to direct losses in milk yield, mastitis leads to significant milk wastage, both due to the disease itself and the necessary withdrawal periods associated with treatment. When cows are treated for mastitis, especially with antibiotics, there are prescribed withdrawal periods during which the milk cannot be sold for human consumption. These withdrawal periods vary depending on the type of antibiotic used. During these periods, milk produced by treated cows must be discarded, resulting in a loss of potentially saleable milk.

The amount of milk discarded is dependent on the cow's daily milk yield and the duration of the withdrawal period. For example, if we consider a 2-day course of treatment with a drug that has a 5-day withdrawal period, a cow producing 30 litres of milk per day will lose 210 litres. In addition, the cumulative effect of multiple treatments throughout the lactation period can result in the loss of thousands of litres of milk per cow.

Subclinical mastitis has an impact on the somatic cell count (SCC) in milk. Milk from cows with SCC above 200,000 cells/mL is generally paid less to farmers. In some cases, it may also be refused by dairy processors because of its reduced quality. It is therefore added to the waste, which exacerbates the farm's overall economic loss.

Premature culling can be a consequence of cattle mastitis

The long-term economic impact of cattle mastitis can be even more significant than the immediate effects of treatment costs and milk loss. Cows with a history of mastitis or cows with persistent or chronic mastitis are at an increased risk of being culled prematurely. The decision to cull a cow is often based on her inability to produce milk at profitable levels, prolonged or recurrent infections, or concerns over animal welfare.

Culling due to mastitis represents a direct financial loss to dairy farmers because it results in the loss of a productive animal and the need for replacement animals, which incurs additional costs. Moreover, mastitis has a detrimental effect on a cow's long-term milk production potential. Even cows that survive the acute phase of mastitis may experience a permanent decrease in milk yield. It has been estimated that the decrease in milk production for the whole lactation can range from 110 to 552 kg ⁴. This reduction in milk yield directly impacts the profitability of dairy farms over the long term, as the cows may be less productive throughout their lives.

Additionally, the genetic potential of the herd is impacted by the culling of cows with a history of mastitis. Dairy farmers invest considerable resources in breeding high-performing cows, and when these animals are culled due to mastitis, it results in the loss of genetic value. This can negatively affect herd genetics and future productivity. 

Key messages

• Cattle mastitis leads to high treatment costs and reduced milk yield.
• Significant milk is discarded due to the disease and treatment withdrawal periods.
• Premature culling of cows reduces long-term profitability and affects herd genetics.

References

1. Potential biomarkers of mastitis in dairy cattle milk identified
2. Bunch, K. J., Heneghan, D. J. S., Hibbitt, K. G., & Rowlands, G. J. (1984). Genetic influences on clinical mastitis and its relationship with milk yield, season and stage of lactation. Livestock Production Science, 11(1), 91-104.
3. Economics of mastitis control in dairy cows - Dairy Global
   
4. Rajala-Schultz, P. J., Gröhn, Y. T., McCulloch, C. E., & Guard, C. L. (1999). Effects of clinical mastitis on milk yield in dairy cows. Journal of dairy science, 82(6), 1213-1220.