Dairy cows: Evaluating heifer mastitis and its costs 

Mastitis treatment and control is one of the largest costs to the UK dairy industry, and it’s also a significant factor in heifer welfare. Read our advice on understanding the impact of mastitis on your heifer herd and profitability.

Mastitis before or after calving, or during the first lactation, significantly affects a heifer’s lifetime yield and udder health. Preventing and managing mastitis is, therefore, critical on dairy farms, both for protecting animal welfare and for managing costs.  

Rearing a healthy adult cow that produces high-quality milk needs careful heifer management from birth to first calving. This requires a considerable cost investment that isn’t usually recovered by a single lactation.*  

To protect this investment, it’s important to be aware of heifer mastitis and the long-term financial impact of infections on your herd and its yield.  

*You can use the AHDB Heifer Rearing Cost Calculator to estimate the costs of rearing.  

Intramammary infections often go unnoticed because heifers aren’t milked before calving, and few farms actively look for infections. However, you have scope to improve the control of mastitis infections in your heifers when:  

• More than 1 in 12 calving heifers have clinical mastitis in the first month, or have blind quarters around calving (with little or no milk production from those quarters)  
• More than 10% of your heifers have a first-test-day somatic cell count (measured between 5 and 35 days in milk) greater than 200,000 cells per ml  

You should investigate these problems urgently. You can use our Mastitis Pattern Analysis Tool to identify and track problems and risks with udder health in your herd.  

Mastitis costs your business money because heifers with mastitis infections at calving are likely to produce less milk, both in the first and subsequent lactations. Research shows that this could mean at least 1,000 litres of milk lost over the animal’s lifetime. 

Not only that, but clinical mastitis affects heifers more severely than older animals. Heifers that calve with mastitis are more likely to be culled during their first lactation.  

The impact of heifer mastitis on an individual animal depends on:  

• The type of mastitis (clinical or subclinical)  
• The severity of the infection  
• The time of infection relative to calving  
• Whether or not the infection is cured  
• When milk production has started   
• The animal’s own immunity  

At the herd level, the impact will depend on:  

• The number of cases  
• The nature of the problem (clinical, subclinical, non-functional quarters)  
• The pathogens involved (major or minor)  
• The animal’s ability to cope with the disease  
• Your response to controlling it  

A study by Nottingham University and Ireland’s Animal and Grassland Research and Innovation Centre looked at eight years of milk-recording data from over 50,000 heifers in nearly 6,000 Irish herds. The group was interested in the impact on lifetime milk production of an increased somatic cell count (SCC) in heifers at calving.  

They found that heifers that calve in over 200,000 cells/ml lose at least 1,000 litres in their lifetime.  

Archer, S. C., Mc Coy, F., Wapenaar, W., Green, M. J. (2013). 'Association between somatic cell count early in the first lactation and the lifetime milk yield of cows in Irish dairy herds'. Journal of Dairy Science, 96, pp. 2,951–9.  

Follow the links below to learn more about the types of mastitis and how to reduce the risks in your heifers: 

If you would like to order a hard copy of the Control of contagious mastitis guide, please contact: Email: publications@ahdb.org.uk or Telephone: 0247 799 0069