The launch of a new vaccine against calf scour underlines why colostrum really is king when it comes to protecting newborn calves. So what steps should producers take to achieve the gold standard?
TEXT RACHAEL PORTER
A 2021 study, carried out in Germany, revealed that 18.5% of calves had scours and it was the most common disease observed in almost 14,000 neonatal calves from 731 dairy herds. An AHDB report put the average immediate cost at nearly £60 per case, but it’s the long-term impact on production that is most significant. An episode of scour in calves is associated with lower average daily liveweight gain and reduced first-lactation milk production. And, alongside respiratory disease, it is one of the top causes of neonatal calf mortality. Adding to the armoury of tools to reduce the impact of calf scour on the UK herd, Boehringer Ingelheim Animal Health has launched a calf scour vaccine – the first to prevent calf diarrhoea caused by E coli F5 and bovine rotavirus, as well as reduce the incidence and severity of calf diarrhoea caused by bovine coronavirus. The vaccine, Fencovis, works by providing passive immunity to calves through maternal colostrum.
“For optimal control of calf scour, it’s important to pay meticulous attention to dry-cow management and calving protocols, and also to ensure that colostrum feeding meets the gold standard,” says Boehringer Ingelheim Animal Health vet Becca Cavill
Calf scour is the symptom of a range of gastrointestinal diseases that impact young calves. “It is multifactorial in nature, involving infectious and non-infectious causes, which can make it difficult to prevent and control,” says Dr Cavill. “Calves are born without circulating antibodies and are reliant on those they absorb from colostrum in the first few hours after birth for protection against infection early in life. Vaccinating pregnant cows against key scour pathogens helps boost the level of antibodies in the colostrum, ensuring calves are optimally protected against this disease,” explains Dr Cavill.
Calf scour: vaccinating dams can help prevent and control disease
The vaccine is given to pregnant heifers and cows, and stimulates the development of antibodies against bovine rotavirus, bovine coronavirus and E coli to increase the level of passive immunity of calves against neonatal diarrhoea caused by these pathogens. “In calves fed colostrum and milk from vaccinated cows, these antibodies have been demonstrated to prevent diarrhoea caused by rotavirus and E coli and reduce the incidence and severity of diarrhoea caused by coronavirus,” says Dr Cavill. “Plus viral shedding in calves infected by rotavirus and coronavirus was also reduced.” That said, it’s not a silver bullet, and Dr Cavill supports a holistic approach to calf rearing that aims to further improve calf resilience and ensure optimal gut and immune health.
“Dry-cow management, calving and colostrum feeding all impact passive transfer of the antibodies produced by the vaccinated dam,” explains Dr Cavill. “Work to protect calves from scours – and other diseases – begins with pregnant cows and heifers. Transition-cow management has to be tip-top to avoid difficult calvings and help maximise colostrum quality.”
She says producers should focus on good dry-cow nutrition: “Ensure they’re fed a balanced ration and maintain body condition score. Avoid dry cows that are too fat or too thin. Ideally, cows should be dried off at condition score of 3 and this should be maintained until calving.
“The aim is to ensure easy calving, so also think about breeding decisions – avoid using large sires on smaller cows and heifers. Easier, stress-free calvings will help to support top-quality colostrum production and effective absorption of antibodies by the calf.”
The next step is to focus on hygiene, starting in the calving pen. “Attention to detail here is critical. The calving pens should be clean and dry, and only used for calving – not for housing sick cows. And protocols around calving should also focus on good hygiene – clean hands, clean clothes and clean equipment.
Looking at the calving pen, Dr Cavill stresses that excellent hygiene and total quality management start here. “Many of the pathogens that cause scour in neonatal calves are carried by adult cows and shed into the calving pen. It can be difficult to equate disease seen in calves days or weeks later in the calf pens to what happened in the calving pen, but this can in fact be the case for scour and bovine respiratory disease.
“Thoroughly cleaning and disinfecting calving pens regularly, and ensuring they are bedded daily and kept as clean and dry as possible, are all vital to help the immunologically naïve calf to survive and thrive.” Scrupulous hygiene is also vital when it comes to colostrum management. Maternally-derived antibodies (MDAs) are absorbed via the gut during the first 24 hours of life.
“After this time, although some local immunity is transferred, absorption into the bloodstream ceases. It’s important to get the basics right,” says Dr Cavill. Feeding 10% of the calf’s bodyweight of good-quality (with a reading of more than 22% on a Brix refractometer) and clean colostrum within the first six hours of life is the cornerstone of any good calf-rearing system.
She adds that colostrum must be harvested hygienically. "The cow should be prepped and milked in the parlour to provide the calf with clean milk that is less likely to be contaminated with some of the aforementioned pathogens. Hygiene is also critical in the management of Johne’s disease.
Know your status and follow your vet’s advice regarding testing, monitoring, management and prevention.” Colostrum can be fed to newborn calves in several ways, and there should be a protocol outlining how this is done, as part of the herd health plan. This protocol should be visible, concise and easy to follow for all members of staff involved in calving and colostrum feeding.
Hygiene is, without doubt, vital right from the outset, including the calving pen, colostrum feeding and then later, in the calf house and feeding equipment. “Poor hygiene at any stage of the calf’s journey can result in sick animals and also make them more susceptible to disease challenge,” says Dr Cavill.
“As with the calving pen, regular cleaning, disinfection and drying of calf pens should be carried out between calves. Use a disinfectant that is active against the pathogens identified on your farm. Remember when it comes to disinfectant it is not a ‘one size fits all’ situation.”
For tip-top feed hygiene, Dr Cavill likes to see a dedicated ‘calf kitchen’ on farm, specifically for the preparation of calf milk. “Make sure buckets and teats are cleaned and disinfected after each use, and that teats are inspected for wear and damage and replaced frequently. Store equipment so it is less likely to become contaminated between feeds. And have running hot and cold water available and plenty of space to prepare milk.
“Setting aside an area like this not only has benefits for calf health but also helps staff to carry out their duties in an effective and pleasant working environment,” she adds.
The #Calfmatters ‘Guide to continuous improvement in your early-life calf health management’ is a great resource for helping producers find the right things to focus on, on their own unit. Visit www.calfmatters.co.uk/resource-shed