CALF SCOURS

A calf gets scours when it accidentally eats more scours-causing germs than its immune system can handle. This happens if:

• Its food/environment contains too many scours-causing germs (hygiene) AND/OR
• Its immune system isn’t working as well as it could be (colostrum management)

Scours-causing germs can stay in the environment for a long time, and healthy animals can shed these germs in their faeces, so all calves will have some exposure. But, following hygiene best practices will reduce the chance of calves getting sick, and will minimise the spread of scours germs from sick to healthy calves. Be careful about your own hygiene around calves, since people can get also get sick from many of the germs that cause scours.

CALF REARING HYGIENE: BEST PRACTICES

In the calving paddock

1. Avoid calving cows on crop
2. Shift springers onto new grass breaks twice a day
3. Teat-spray the springers when they go through the milking shed
4. Pick calves up twice a day (more during wet weather)
5. Keep the calf trailer clean and dry
6. Dip/spray navels with 7-10% alcohol-based iodine before and after transport to the calf shed (NOT teat spray or 2.5% stock iodine)

For colostrum (first milking) & transition milk (from second and later milkings)

1. Dump colostrum and milk from scouring/sick cows
2. Clean dirty teats with teat wipes/dry paper towels before cupping up colostrums
3. Avoid pooling colostrum if possible
4. Keep lids on colostrum/transition milk storage containers
5. Use colostrum & transition milk as soon as possible after collection.
6. If you store colostrum or transition milk:
   1. Keep it cool
   2. Add 10mL of a 50% potassium sorbate solution per litre
   3. Stir it daily
   4. Use within 7 days
7. At each feeding:
   1. Start with new-borns
   2. Feed healthy animals from younger to older
   3. Feed sick pens last, ideally with separate equipment.
8. Clean calf feeding equipment with soap and warm water daily
9. If equipment is shared between sick and healthy calves, then, after each time it’s used for sick calves:
   1. Clean it with hot water and soap
   2. Disinfect it with 250mL bleach per 20L water
   3. Rinse it with clean water

In the calf shed

1. Separate calf pens with solid, easy-to-clean partitions. If air quality suffers by doing this, then only isolate sick pens with solid dividers
2. Manage bedding so calves are dry at all times
3. Spray pens with a disinfectant safe to be used around calves regularly
4. Use “all in, all out” management of calf pens
   1. Fill calf sheds up pen by pen (group by age)
   2. Don’t move calves from pen to pen (except if moving a calf to a sick pen or to a “recovered calf” pen)
5. Remove a sick calf from a pen of healthy calves ASAP
6. If more than 1/3 of animals in a pen are scouring, leave all of the calves in there together and make that a sick pen
7. Clean boots/waterproofs and change to clean gloves when exiting sick pens. Set up a washing station outside of each sick pen with:
   1. bucket of disinfectant water + scrub brush (change water — at least daily)
   2. box of clean gloves
   3. rubbish bin
8. When calf sheds are empty:
   1. remove old bedding
   2. water blast pens with disinfectant solution
   3. let pens dry before re-use
9. Consider vaccinating the herd with Rotavec® Corona. Calves fed colostrum and transition milk from cows vaccinated with Rotavec Corona shed less rotavirus and corona virus in their faeces.
10. To help keep you and your family from getting sick, always wear gloves when working with calves. Wash your hands and change your clothes before interacting with children or anyone with a fragile immune system.

REFERENCES

1. Berge, ACB et al. (2009). Evaluation of the effects of oral colostrum supplementation during the first fourteen days on the health and performance of pre-weaned calves. Journal of Dairy Science. 92:286–95
2. Chuck, G. (2015). Calfwise: right from the start. 2015 Proceedings of the Society of Dairy Cattle Veterinarians of the NZVA Annual Conference. p71-80.
3. Chuck, G. (2015). Targeting calf-hood morbidity & mortality. 2015 Proceedings of the Society of Dairy Cattle Veterinarians of he NZVA Annual Conference. p227-232.
4. Conneely, M. et al. (2013). Factors associated with the concentration of immunoglobulin G in the colostrum of dairy cows. Animal 7:11. p1824-1832. https://www.cambridge.org/core/journals/animal/
5. Cuttance, E. & Denholm, K. (2016). Dairy NZ technical series. Colostrum management: giving calves a great start to life. Accessed online: www.dairynz.co.nz/media/4439069/tech-series-june-2016-colostrum-management.pdf
6. Denholm, K et al. (2017). Associations between management practices and colostrum quality on New Zealand dairy farms. New Zealand Veterinary Journal. 65:5. p257-263. DOI: 10.1080/00480169.2017.1342575
7. Faber, SN et al. (2005). Case study: effects of colostrum ingestion on lactational performance. The Professional Animal Scientist. 21:420-425.
8. Godden, SM et al. (2012). Heat treated colostrum and reduced morbidity in preweaned dairy calves: Results of a randomised trial and examination of mechanisms of effectiveness. Journal of Dairy Science. 95: 4029-4040.
9. Gomes, V. et al. (2011). Factors affecting immunoglobulin concentration in colostrum of healthy holstein cows immediately after delivery. Pesq. Vet. Bras. 31:1. http://dx.doi.org/10.1590/S0100-736X2011001300009
10. Morrison, S. (2013). The impact of calf health on future performance. Veterinary Ireland Journal. 3:264–8.
11. Parkinson, TJ et al. (2010). Calves: management & disease. Diseases of cattle in Australasia: a comprehensive textbook. VetLearn. pp.627-659.
12. Recca, A. et al. (2003). Comparative lactogenic antibody responses of cattle from European field trials with a new enteric disease vaccine. Vet Record. 152: 751-752.
13. Schouten, B, et al. (2005). Oral electrolytes? A comparative study of some commercial electrolytes. NZVA VetScript.18:6. pp 35-39.

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