Amanda Kilby, MSD animal health veterinarian, explains what Bovine Viral Diarrhoea is and how you can control it.
A calf gets scours when it accidentally ingests more scours-causing pathogens than its immune system can handle.
Unfortunately, the pathogens that cause scours can be found in the faecal material of healthy animals, and they can stay in the environment for days or even months, so all calves will have some exposure.
But, you can reduce the risk of calves getting sick by keeping colostrum, calf milk and the calves’ environment as clean as possible.
Tips to reduce risk:
- Dump colostrum and milk from scouring cows
- If cows in the colostrum mob have dirty udders, clean their teats with dry paper towels or alcohol teat wipes before cupping.
- Keep colostrum and transition milk in covered containers after collection. Use it asap.
- Clean & disinfect all calf feeding equipment and test buckets every day.
- At each feeding, begin with the new-born calves first. Then, feed all the healthy animals, moving from youngest to oldest. Feed sick pens last, ideally with dedicated equipment.
- Divide calf pens from one another with solid, easy-to-clean plastic or metal partitions or at least isolate sick pens with solid partitions, so sick calves don’t have direct contact with healthy calves.
- Keep enough fresh bedding in each pen so that calves are always dry.
- Spraying pens with disinfectant will only work if no organic matter is present.
- As calves come in, fill the shed pen-by-pen, so they’re with other calves their age. Leave them in the same pen until they go outside. This is sometimes called “all-in, all-out” management.
- Remove an individual sick calf from a pen of healthy calves as soon as you see that it’s scouring. Ideally, after they’ve recovered, these sick calves should go into another “recovered calf pen” instead of back with healthy calves.
- If more than a third of the animals in a pen are scouring, leave all the calves together and make that a sick pen.
- Clean and disinfect your boots, waterproofs, and change your gloves whenever you move from a sick pen to a healthy pen. Change foot baths daily.
- After calves are in the calf shed, ensure that you follow the 3 Q’s (Quickly, Quantity, Quality) and that you’re feeding the cleanest possible colostrum (“gold” - from the first milking), and transition milk (from the second and subsequent milkings).
Here is a summary of what to do if you have scouring calves:
- Isolate individual scouring calves or pens of scouring calves as early as possible.
- Check your hygiene and colostrum management practices. Watch our other Top Farmers’ videos for more information about these topics.
- Get your vet involved right away to help you contain the current outbreak and prevent an outbreak from happening again.
- Alternate milk and electrolyte feeds to scouring calves, providing 6-8 L of total fluids each day. Tube calves if they won’t drink. Provide free choice electrolytes overnight in pens of scouring calves, and ensure clean water is always available to all calves.
- Treat scouring calves with any other medications prescribed by your vet. Check with your vet that you’re using them correctly.
- Lastly, consider vaccinating the herd with Rotavec Corona. Calves fed colostrum from cows vaccinated with Rotavec Corona shed a lot less rotavirus & coronavirus in their faeces, therefore there is less likelihood of disease spread to other calves due to environmental contamination.
Remember to also be careful about your own hygiene around scouring calves so that you and your family don’t get sick. Always wear gloves in the calf shed and wash your hands and change clothes before eating and before interacting with young children, the elderly, pregnant women, or anyone else with a fragile immune system.
Consistently doing these things requires constant attention-to-detail, but, if you’re able to get the whole team on board before calving season begins, then, in the long-run, you’ll save time, money, stress, and, most importantly, calves.
For helpful videos and fact sheets which expand on the information in this article visit www.topfarmers.co.nz , a reference library of industry best practice for some key animal health management areas.
• Kim Kelly is MSD Animal Health’s regional technical advisor/vet.