Four in five dairy farmers in the UK have experienced cryptosporidiosis in their herds, with significant financial and welfare implications, according to new research.
A study conducted at Harper Adams University found that 84% of surveyed farmers had dealt with cryptosporidiosis outbreaks, with nearly 60% rating the severity as seven or higher, with 10 being the most severe.
The survey of 63 farmers from across the UK in spring 2024 highlighted financial losses ranging from £300 to £30,000, with 68% of respondents citing financial strain due to increased vet bills, extended rearing times, and lower sale values.
Almost three-quarters (70%) of respondents said affected calves were less profitable, with poor growth rates being the most common reason.
This mirrors other UK studies, which show that calves infected within the first 16 days of life gained significantly less weight over six months, leading to a potential £161 reduction in sale price per calf.
Additional costs include increased labour for managing sick calves.
Cryptosporidiosis
Cryptosporidiosis occurs when calves ingest the parasitic protozoan cryptosporidium parvum (C. parvum), which produces vast numbers of encysted eggs (oocysts) shed in the faeces of infected animals.
Calves between five days and two weeks-of-age are most affected, with symptoms including colic (gut pain), reduced feed intake, watery scour, and dehydration.
The latest study was prompted by BSc animal production science graduate, Alice Powell of Massey Feeds, after witnessing the devastating effects of C. parvum firsthand.
“On one of the farms I worked at, there were a lot of calf deaths due to C. parvum, and the calves were severely dehydrated,” she explained.
“You could just smell it in the sheds. After testing, they found they had C. parvum, so they became very strict about cleaning, disinfecting, and colostrum management.”
Powell said the farm even invested in new calf accommodation with non-permeable surfaces that were easier to clean and disinfect.
Her study revealed gaps in biosecurity and prevention. Some of the measures ranked as most important also had a high number of farmers stating they were not important.
E.g., 28 farmers considered thorough cleaning of feeding equipment very important, while 18 disagreed, stating it was not important. However, four in five farmers reported cleaning and disinfecting after an outbreak.
More than half of respondents were using preventive measures, with cleaning equipment, good colostrum management, and correct calving protocols ranked as the most effective.
One issue raised was that many farmers were either using the wrong disinfectant or unaware that only certain disinfectants are effective against cryptosporidiosis.
“Having the correct electrolyte protocol is also crucial. Some farmers mentioned adding electrolytes to milk, but this can affect the osmolality in the calf’s digestive system, leading to dehydration rather than rehydration. Electrolytes must be provided separately from milk feeds,” Powell added.
Vaccine
The research also gauged awareness of Bovilis Cryptium, the first-ever vaccine for cryptosporidiosis.
At the time of the survey, it was not yet available in the UK, having only been launched in late 2024. However, 81% of respondents who were aware of it said they would use it if it became available.
Administered to pregnant cows in the third trimester, the vaccine requires two doses given 4–5 weeks apart, with the final dose completed at least three weeks before calving.
For subsequent pregnancies, a single booster dose is required.
Dr. Kat Baxter-Smith from MSD Animal Health said: “When used alongside excellent colostrum management and strict hygiene, vaccination can significantly improve calf health and farm efficiency.”
