Managing calf scour effectively

Calf scour remains the biggest cause of disease and death in neonatal calves, along with pneumonia, with a range of short and long-term implications for health and profitability – from treatment costs and extra time caring for sick calves, to impacts on growth rates and ability to hit targets for age at first calving of 24 months.

Nutritional scour, which is generally mild and resolves once the underlying cause is addressed, is one cause, but infectious scour is more common and often more serious.

It’s most often caused by Cryptosporidium parvum and rotavirus, which often occur alongside each other, but other causes are E. coli, coronavirus and salmonella – and as calves get a little older, coccidiosis.

Vaccination 

Vaccinating cows can increase the levels of specific antibodies in their colostrum – Bovigen Scour contains rotavirus, coronavirus, and E. coli K99, three of the most common infectious causes of scour in young calves.

The cow receives a single intramuscular injection (3ml dose per cow) during the final trimester of pregnancy, 12-3 weeks before she’s due to calve.

The aim is to make vaccinating as simple for farmers as possible, so Bovigen has a 10-day broach life, meaning that cows do not have to be brought in and treated on the same day. In addition, being available in 5- and 30-dose vials allows for less wastage.  

The good news is the cost of the vaccine compared to the cost of disease means the benefits and return on investment are high.

For a non-antibiotic prevention and treatment option for scour caused by Cryptosporidium parvum, Virbac offers Kriptazen, a halofuginone with a twist. It can be used if calves have diarrhoea and have been diagnosed with cryptosporidiosis, but also as a preventative within 48 hours after birth, if you know you have a history of crypto on your farm.   

One unique feature of Kriptazen is the pump – with many halofuginones you work out the calf’s weight and calculate the dosage needed up to the nearest 4ml, but Kriptazen can be dosed to the nearest 10kg of weight by simply twisting the pump.

This is important with halofuginone as it has quite a narrow safety index, so calves can get signs of toxicity if the dosage is too high. As well as reducing time spent dosing product, it also means farmers will potentially use less product, which could build up to quite a saving.

“It’s just much more convenient, as you can dose up to 60kg with one pump, whereas with other products, you might have to give them multiple 4ml pumps,” Kate concluded.

Colostrum management 

It’s essential to ensure the calf then gets enough good quality colostrum, quickly enough after they’re born, so they can absorb the antibodies. While vaccination can be a really powerful tool in the armoury, it will not make up for other issues such as poor colostrum management or hygiene, Kate noted.

It’s important to follow industry recommendations for the three Qs (quantity, quality and quickly). This means 10–12% of their bodyweight being administered ideally within the first two hours (and must be within the first six hours), and making sure the colostrum is clean and of sufficient quality (at least 22% on the Brix refractometer). 

Hygiene protocol

Kate explained: “It’s virtually impossible to eliminate these pathogens; they are ubiquitous on the majority of farms, particularly cryptosporidia and rotavirus, but what you can do is significantly reduce the challenge that the calves actually get exposed to by good hygiene.”

This includes cleaning out and disinfecting properly between animals if they’re in individual pens, or between groups of animals, as well as keeping calving areas as clean as possible, as many of the pathogens that cause scour can be picked up from the dams.

“When you disinfect, make sure you use a product that is actually effective against all the different pathogens you’re trying to kill, particularly cryptosporidia, as not everything does kill crypto,” she added.

“Think about when you use it, reading the instructions, mixing it up properly and don’t leave it hanging around because the efficacy can reduce with time. Also make sure you adhere to the right contact time.”

Pay attention to all parts of the pens when cleaning and disinfecting – not just the floor but the sides of the pen, gates, feeding equipment and even things like the wheelbarrow you use to transport the calf from the calving shed to its accommodation. 

Stress 

Minimising stress is always important for immune function and reducing the risk of any disease. Causes of stress can include: cold and heat, mixing, weaning and any other stressful management changes.

Kate concluded: “There is some data that shows that supplementing calves with trace minerals ahead of these stress points can help reduce the rates of disease.

“Multimin, an injectable trace mineral containing copper, zinc, manganese and selenium, can be given to calves from birth and has been shown to reduce disease and boost their immune response.”

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