Last winter MSD Animal Health was able to monitor scour pathogen incidence on a number of UK calf rearing units. “Between October 2020 and March 2021, we were able to examine different scour pathogen incidence thanks to our own disease surveillance scheme based on faecal sample test kits,” explains MSD Animal Health Livestock Veterinary Adviser, Dr Kat Baxter-Smith.
She adds that these ScourCheck kits are convenient, easy-to-use and accurate on farm – and will pick up the presence of rotavirus, coronavirus, E. coli or cryptosporidium infections. Their use helps farmers and their vets to discuss appropriate scour disease management approaches, depending on the mix of infectious organisms identified. Other pathogens, such as Salmonella spp and coccidia, should be identified by full lab analysis.
“During this six-month period, we gathered data from 112 farms and 61 percent of faecal samples taken from these calf rearing units returned a positive result – with 23 percent of these positive tests having mixed infections.”
Kat stresses that, unfortunately, treatment for infectious calf scours can be challenging and time consuming, so the key to better disease control lies in prevention of this troublesome young animal health issue.
“We know that scour continues to be a significant disease problem in young calves, particularly over the winter months. Indeed, scour is the main cause of death in animals under two months of age. The husbandry aim, therefore, simply has to be trying to stop the disease occurring in the first place,” she says.
“Practically, this means making sure your cow colostrum is as good as it can be, in addition to ensuring good environmental hygiene and management. Indeed, a good first step in terms of making your calf rearing enterprise more resilient to infectious scour problems is to give your dry cows a vaccine to boost dam colostrum quality pre-calving – and then feeding enough of this fortified feed to your newborn calves.”
Kat says that calves are most at risk from infectious scours during the first one to four weeks of life and need a source of protection – through passive transfer of antibodies in the colostrum – to help keep them healthy. On many units, she suggests, normal colostrum may not provide enough antibodies.
“However, vaccination of the calf’s mother with Bovilis Rotavec Corona between 12 and 3 weeks before calving boosts colostrum quality, allowing you to feed high levels of antibodies against rotavirus, coronavirus and E.coli F5 (K99) in early life. Calves gain protection by drinking this fortified colostrum from their vaccinated mothers.
“To ensure this passive transfer of antibodies from the dam to calves, four litres of colostrum (or at least 10 percent of calf body weight) containing 50g/litre of IgG antibodies should be fed within the first four hours of birth. This should be followed by two additional litres within 12 hours of birth. For calves left on the cow, getting four litres of colostrum requires approximately 20 minutes of continuous suckling,” she says.