The treatment and control of mastitis is arguably one of the largest losses on a UK dairy farm and globally costs the dairy industry an estimated £14-23 billion each year.
These costs are in the form of antibiotic contaminated milk which has to be discarded, a reduction in yields due to illness, costs of veterinary care and medicines, reduced longevity due to premature culling and increased demand for labour when caring for cows with mastitis.
Abingdon Health, specialist in rapid diagnostic technology and tenants of the BioHub laboratory at Birmingham University, has secured funding, along with the University of Glasgow, to develop a quick on-farm test for mastitis.
Dr David Pritchard, chief technical officer of Abingdon Health, says: “The pressure to reduce the use of antimicrobials in food production is growing rapidly.
"To do this we need to provide farmers with rapid diagnostic tests which guide the choice of antibiotic and ensure animals are treated quickly and effectively with the right antibiotic.”
Current methods of identifying mastitis can be subjective or costly and often take a long time to establish the cause of infection, they can also contribute towards excessive use of antibiotics.
The California mastitis test is a common method used to identify cows with raised somatic cell count (SCC) which confirms cases of sub-clinical mastitis.
Milk from cows suspected to be suffering from mastitis is mixed with a reagent, this causes milk high in SCC to turn into a gel-like substance depending on level of infection, it is then scored from zero-three (scores of two or three are considered to be positive results).
The CMT is cheap to carry out however results are subjective; what is a level 2 for one person may not be for another.
An alternative is to send milk samples away to a lab to identify the type of pathogen involved in the specific case of mastitis, this can be more costly and can take 24-48 hours but the results are more accurate and they allow for more specific treatment to be administered.
Certain antimicrobial treatments are only suitable for treating certain classes of bacteria, so it is important to identify the bacteria in order to use the correct type of antibiotic.
The new test will be in the form of a lateral flow test, similar to a pregnancy test. This technology detects the presence or absence of specific pathogens.
It will aim to provide sensitive measurements to allow the class of bacteria to be identified and determine whether the mastitis is caused by gram-positive or gram-negative bacteria.
Gram-negative bacteria, such as E.coli are more resilient to treatment by antibiotics as they have a largely impermeable cell wall. They are also more likely to become resistant.
However, antibiotics are more effective in treating infection with gram-positive bacteria such as streptococcus agalactiae and staphylococcus aureus, both common causes of mastitis in cattle.
Dr Pritchard says: “We also believe the test will provide benefits to the dairy industry in terms of milk quality and yield, and to the cattle in terms of animal welfare.”
The new test will ensure the cow is quickly prescribed the right antibiotic to treat the infection, with the aim of reducing the use of inappropriate antibiotics and control the spread of infection between cows.