The majority of the herd will now have calves on the ground as we get further into February which means the risk of calf scour in the calf shed increases.
The spring period can be hectic and farmers can struggle to get everything completed to the highest standard when cows are dropping calves rapidly.
However, farmers need to ensure the longevity and performance of their calves through proper feeding of colostrum, hygiene and proper rumen development to ensure proper weight gains are being achieved by calves without any disease creeping in.
Scour is the biggest killer of young calves on dairy farms, and although completely eliminating cases on farms will be difficult, the number and severity of cases can be reduced.
Scour refers to watery faeces and results from a badly damaged gut, which leads to a loss in function and an intestine that is not functioning properly which causes the calf to lose salts and water in the form of diarrhoea.
The initial damage to the gut is caused by bugs, and once the damage is done, the calf will be scouring until the intestine is repaired.
Calf scour is most commonly caused by parasites such as cryptodporidia and coccidia, or viruses like rotavirus and coronavirus. It is less commonly caused by bacteria such as salmonella and Escherichia coli (E.coli).
Calf scour
Ideally, calves that are showing symptoms of scour should be separated from the group, as this will prevent the spread of the infection and give the calf a better chance to recover.
Sometimes separation might not occur on farm due to the inconvenience of it amid an already hectic schedule during spring.
However, to limit the infectious pressure in the calf shed, separation is the best call to action to ensure all calves’ health is prioritised and it is vital that the calf with the scour has her fluids and salts replaced immediately.
Healthy calves need up to 4L of fluids per day and scouring calves need an additional 4L to replace lost fluids.
The calf with scour should be given one or two extra feeds of about 2L each of electrolytes or some sort of good quality rehydration solution as soon as the calf starts scouring.
If the calf is too weak to suck or drink the electrolytes, the calf should be stomach tubed to get something into the system.
A scouring calf is losing fluid which needs to be replaced, so it is important to continue to offer milk feeds, along with extra feeds of electrolytes.
It is not uncommon for some farmers to stop feeding milk to scouring calves, but research has shown that offering calves their milk feeds can reduce the length of sickness and recovery time.
Feeding milk separately while the calf is sick actually helps with the healing of the intestine, so offering it to the calf for as long as they want to drink it should continue, and the milk should not be diluted.
Prevention
Feeding decent quality colostrum is the key to calf scour prevention. Whether a calf stays healthy or gets scour is determined by the balance between the resistance of the calf and the level of infection it is exposed to.
Good quality colostrum should read 22-23% on a colostrometer and farmers should make sure they get their colostrum tested each time to ensure calves are receiving their required antibodies that helps fight off disease and build immunity.
Good hygiene is crucial as keeping the calf comfortable, dry and clean is important through all stages of calf rearing.
Cryptosporidia can cause severe diarrhoea in calves who have received adequate amounts of colostrum, and when hygiene is poor.
Individual calf pens should be cleared out between calves and when calves are grouped together, they should be put into clean pens, as clean, dry bedding is essential wherever the calf is housed.
As the calving season progresses, there is a tendency for infection to build up, so it is important to ensure that your calf housing is as clean at the end of the season as at the start.
Another thing that might get overlooked as the calving season goes on, is the cleanliness of the feeding equipment – make sure that all teats and buckets are thoroughly washed after every use.
Your feeding equipment should be thoroughly washed after each feeding with hot water, and should be cleaned with a detergent and descaler after every few feeds.
