Calf vaccines identified as low-hanging fruit in antibiotic reduction

REDUCING antibiotic use in calves could represent a significant opportunity for dairy farmers to cut overall antimicrobial usage, according to the latest industry data¹, which highlights oral antibiotics as a growing contributor to on-farm antibiotic use.

Figures released by RUMA at the end of 2025 show that calf oral antibiotic sales

more than doubled in 2024, rising from 1.92 mg/kg defined daily dose for animals (DDDvet)

to 4.03 mg/kg DDDvet.

RUMA has now introduced a new target to reduce calf oral antibiotic use by 10% year on year, underlining the importance of addressing antibiotic use in youngstock.

Dr Kat Baxter Smith

Supporting this, the latest Kingshay results, covering 967 dairy herds across 136

veterinary practices, show that while average total antimicrobial usage has continued to

decline, falling to 12.2 mg/kg PCU in 2025, down from 12.7 mg/kg PCU in 2024 and 15.7

mg/kg PCU in 2020, usage remains heavily concentrated within a subset of farms.

The data revealed that herds ranking in the highest quartile for antibiotic use

accounted for 50% of total antibiotics used, with oral products, often administered to calves

for respiratory disease and scour, making up 13% of total antibiotic use within these higher-

using herds.

While Kingshay data showed calf oral antibiotic usage fell from 1.38 mg/kg PCU to

1.05 mg/kg PCU between 2024 and 2025, the contrasting RUMA figures highlight that oral

antibiotic use in calves remains a key area of focus for the industry.

Emma Puddy, Kingshay farm services specialist and report co-author, said the use of

oral antibiotics in calves can significantly increase overall antimicrobial usage.

“If you use oral antibiotics within calves, you will see that your usage is significantly

higher than maybe the group average, and I think that is really highlighted in our report,” she said.

“Oral antibiotics tend to really increase your overall antimicrobial usage. Injectable treatments are for just one animal and involve only a small amount of

product, whereas if you’re treating a whole pen of calves, because 5% of them are getting

sick and you want to stop the rest, that’s when oral antibiotics tend to be used more.”

Kingshay training consultant and vet Michael Head said a strong starting point for

reducing antimicrobial use is monitoring disease incidence through an effective herd health

plan, with vaccination forming a key part of that approach.

He said: “Effective vaccination strategies form part of this because people can tend to reach

for antibiotics, but the benefits of strong immunity, genetic advances and good nutrition

mean cattle are better able to resist disease and, in turn, reduce the need for antimicrobials."

Despite this, the latest AHDB vaccine report shows that fewer than 50% of calves

are vaccinated against respiratory disease, while only around a quarter of producers

vaccinate for calf enteritis (calf scour).

Mr Head believes the introduction of two vaccines, Bovilis Cryptium for protection

against calf scour caused by cryptosporidiosis, and a vaccine for Mycoplasma bovis, could

make a meaningful difference.

“Their use is certainly increasing at pace, and I’m already hearing farmers recommending the use of vaccines to other farmers," he said.

Mr Head also highlighted the longer-term consequences of disease in calves.

“Calf diseases have significant onward consequences with regard to the future health

of those animals, their longevity and their disease resistance,” he said.

Dr Kat Baxter Smith, a vet at MSD Animal Health, said the Kingshay findings

underline how oral antibiotic use in calves can quickly influence overall farm figures and why

prevention through vaccination and management changes could provide a low-hanging fruit

for farmers to reduce overall antibiotic use in their youngstock.

“Respiratory disease and scours remain two of the most common reasons antibiotics

are used in young calves," she said.

"By tackling these challenges earlier through vaccination and good management, farmers can significantly reduce the need for antimicrobial intervention.

“Scours caused by cryptosporidiosis can be particularly difficult to manage, and while

some antibiotics don’t always treat the underlying cause, they are often used to manage

secondary infections.

"There have also been reports of some resistance to paromomycin 4 in E.coli K99, a commonly used antibiotic for treating E.coli K99 infections and is also licenced

for use against cryptosporidiosis."

She added that vaccination can play an important role in reducing disease pressure.

“Using vaccines such as Bovilis Rotavec Corona for rotavirus, coronavirus, and E.

coli and Bovilis Cryptium for Cryptosporidium parvum is one of the most effective ways to

reduce the incidence of neonatal diarrhoea.

"Vaccination used alongside good management such as housing, ventilation and colostrum management not only helps aid calf health, but supports better lifetime performance, resilience and productivity within the herd.”