11 ways to avoid scour in calves

Calf scour is one of the biggest health issues in youngstock causing serious financial losses. 70% of farmers have seen scour in calves under six months of age during the previous 12 months and more than 40% of producers have lost animals to the disease over the same period. (1)

Scour can either be nutritional or infectious however we are unable to tell the difference without a laboratory test, this can be achieved with a dung sample and the help of your vet.

Nutritional scour can be due to the components of the milk replacer or the feeding and mixing of the CMR. The cheaper not so high-quality milk replacers can contain indigestible vegetable proteins and higher ash levels which usually means higher salt levels. Both the high salt levels and high levels of poorer quality vegetable proteins can cause scour simply due to an osmotic effect in the large intestine, the molecules, therefore, draw water into the gut lumen resulting in diarrhoea. Badly mixed powder, irregular feeding and inconsistent volumes and temperatures can also result in a nutritional upset.

Secondly, there is infectious scour, as we know every farm has pathogens. Whether the calves get a disease or not depends on the hygiene, management and immunity of the animal. Rotavirus is the most common cause of scour for calves aged 4-14 days. Rotavirus attacks the epithelial cells of the gut lining, the gut villi are then damaged meaning they are no longer able to absorb nutrients, and waters and salts are lost in the form of scour. (2)

Read more on the effects of dehydration in calves

The newborn calf is dependent on the antibodies it received via the damns colostrum this protection only last 3 – 4 days therefore it reduces rather than eliminates the risk of Rota Virus. Continued feeding of colostrum/transition milk can extend this period reducing the risk.

The second most common cause of scour is Cryptosporidium this parasite normally infects the calf shortly after birth and causes scour at 5-7 days. Once ingested the parasite attaches to the gut wall and multiplies which cause damage, this then reduces the ability of the calf to digest food leading to a watery scour. Cryptosporidium is spread through the oocysts that are secreted in the faeces of infected cows or calves contaminating the environment, calves then become infected when they consumed contaminated feed or water.

Remove the calf from the group this will help prevent the spread of infection. It is important to replace the salts and fluids that are lost due to scour. Give one or two feeds extra feed (2 litres each) of good-quality oral rehydration solution. Continue to feed the milk or milk replacer as this will not prolong or worsen the scour. It will help with the healing of the intestine.

Sources : 1. ADAS Report: Economic impact of health and welfare issues in beef cattle and sheep in England (p. 35/36), 2. Calfology.com, 3. Animalhealthireland.ie