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Tips for a healthy calf crop

On-farm biosecurity to reduce disease risk just makes good business sense

Calving season poses the greatest risk for spread of disease on our farms or between neighbouring farms and this is repeated every year. That makes it worth reviewing some common biosecurity practices, which should be stepped up to prevent a scours, respiratory or other disease outbreak.

It is a time when both the cow herd, because of calving stress, and the newborns are subjected to multiple pressures on their immune systems. This coupled with weather changes and close confinement can really increase the risk of disease. If new additions to the herd are made (such as bred heifers) or commingling occur your odds of seeing sick calves increases for sure.

With biosecurity one needs to consider exposure to organisms from outside the herd and the concentration and spread of infectious organisms within or between individuals in the herd.

Your own individual herd becomes exposed over time to infectious organisms that are present in a low level. The cattle’s immune systems will develop protection to these organisms very similar to a vaccination. If exposure to an organism at a high level or to one that is new — there has been no exposure in the past — puts the herd at risk of being infected with the disease. The outbreak occurs once one animal is infected and starts shedding that organism at a high level in close proximity to other susceptible animals.

Keep diseases out

For outside exposure we can eliminate it almost to zero by sticking to some very clear rules.

Do not bring in any herd additions either close to or for sure during calving season. This would be cow-calf pairs, bred cows or calves to mother up with cows that have lost calves.

To avoid having cows go unproductive when their calves are lost several things can be done. Many herds have a high incidence of twins. Where possible switch the least valuable calf as these calves do go under considerably greater stress adapting to the new mother who may not want them. The calf most often orphaned is the freemartin heifer in the case of the heifer/bull twins.

At preg checking good managers often keep one or two possible cull cows if they are bred early as potential surrogate mothers who will have their calves removed at calving and then be culled. They need to be calving relatively early in the season for this to work. This avoids the need to bring in any calves from outside sources. Dairy calves especially seem very susceptible to contracting scours in a beef situation and becoming the initiating case.

If you do purchase bred animals isolate them for a time and make sure they are vaccinated and fit into the farm’s vaccination program. You may need to contact the owner if past treatments are not described in the sale catalogue. If no history of vaccination then you need to assume they are not vaccinated and may have not been treated for lice or internal worms. If you have a scours vaccination program give that to the new additions.

Discourage visitors and wash your coveralls

Visitors touring through the herd should be kept to an absolute minimum to zero during calving season. Although everyone likes seeing newborn calves it is also dangerous for inexperienced people with overprotective mothers around.

At the very least if outsiders do enter make sure they have street clothes or use a boot dip and keep them out of the calving areas. A boot dip can contain a disinfectant called Virkon, or water vinegar mixed 50/50 works as well. Virkon is very safe and is good for most bacteria viruses and fungi. Better yet, have a few pairs of thick plastic boots to slip over their own boots. The boot dip should be used on entry and exit from either a contaminated area or one which you want to keep protected. Both boot dips and plastic booties create a heightened awareness on how important biosecurity really is.

Change the boot dip at least every few days or when soiled. It is best to also have a good brush handy to encourage cleaning the soiled areas. Disinfectant mats can also be used as long as they are replenished and cleaned.

Ranchers or their herdsmen have to regularly wash their coveralls and outer clothing. This is probably “THE” most common spread of infectious organisms around the farm. I have seen many of these bib overalls extremely soiled from carrying newborn calves, calving cows or treating calves. With the direct contact with many calves it is clearly evident this is where the greatest potential spread of infection can occur. As producers, keep yourselves clean by using a calving suit, which is easily cleanable, and use obstetrical gloves when checking the cows.

If you do get a scours or respiratory case it is best to isolate that animal away from the calving area. Treat it daily after the calving cows have been checked. Dip your boots and either change coveralls or have one pair present to put on for the treatments. Remember any instruments such as feed buckets forks, shovels, or esophageal feeders should be used solely for sick calves and definitely cleaned and disinfected before using on the next case. Efforts spent here may eliminate or slow a scours outbreak.

Different feeders

Many producers give slow or sluggish calves colostrum so I recommend using a different feeder for sick calves and newborns. Label them appropriately. Make sure and have an isolation area to contain several cow-calf pairs. Individual isolation is best as sick calves are already compromised from catching whatever other sick calves carry. It is much better putting them together than exposing the healthy herd to this threat of disease.

To minimize a potential huge outbreak in the calving area itself, utilize several fields and have 50 cow-calf units in each. This generally happens in chronological order the first 50 go to a certain field the next 50 another field and so on. That way if a disease outbreak does happen it can be kept hopefully to just the one pen. Sick calves are easier to see, catch and treat in a smaller group. In the morning check the healthy groups first and proceed to the sick pens later. If treating, anything you use such as syringes needles balling guns and other tools should not be used on healthy stock unless first disinfected.

About the author

Columnist

Roy Lewis is an Alberta-based veterinarian specializing in large-animal practice. He is also a part-time technical services vet for Merck Animal Health.

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