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Prevent scours from mucking up your calves’ potential

Doug Hammon for Progressive Dairy Published on 02 March 2021

Scours is responsible for 56.5% of mortality among pre-weaned dairy calves, making it the leading cause of calf death and sickness. How can you make sure your calves’ health, growth and productivity are not affected? Let’s look at some of the ways you can better manage calves to reduce the risk of exposure and illness.

Feed high-quality colostrum

To facilitate passive transfer of antibodies from dam to calf, experts recommend that calves receive 10% of their birthweight in colostrum (4 litres for Holsteins) within the first two hours of birth and another 2 litres within the next six hours. However, this advice only tells part of the story – the quality of the colostrum is just as important as the amount you feed. Keep these three considerations in mind to ensure your calves receive a strong immune foundation:



1. Remember: Quality colostrum starts with the cow. Cows begin transferring antibodies into their milk about five weeks prior to calving. During that crucial window, you should support cows’ immune systems with adequate nutrition and environmental conditions to maximize the immunoglobulin G (IgG) antibody content in their milk. Administer a scours vaccine to provide specific immunity for pathogens that cause scours. All scours vaccines are labeled for pregnant cows to help ensure colostrum will protect calves from common causes of scours.

2. Collect and cool colostrum promptly. Ideally, cows should be milked within a few hours of freshening to obtain the highest-quality colostrum. While that may not be feasible on large-scale dairy operations, keep in mind that IgG concentrations drop 3.7% each hour that passes, so supplementation may be necessary. Once the colostrum is collected, feed it or cool it below 15ºC within 30 minutes to minimize bacterial growth.

3. Test colostrum quality and make adjustments as needed. You should perform quality control checks on colostrum collected from each cow to monitor IgG content and bacterial contamination. Aim for a Brix refractometer reading of at least 22%, a plate count of less than 50,000 colony-forming units (CFUs) per milliliter and a coliform count of less than 5,000 CFUs per milliliter. If you’re not meeting these quality standards, revisit your dry cow management program and check to make sure your milking and storage equipment are clean.

Provide quality nutrition

Setting calves up for success doesn’t end with colostrum. Continue to help support healthy calf immunity by following these feeding tips and talking with your nutritionist to ensure your calf nutrition program is complete:

1. Consistency is key. To minimize calf gastrointestinal upset and diarrhea, keep feedings consistent – pay attention to milk temperature, weight and percentage of solids as well as the time interval between feedings. It also is important to routinely sanitize storage tanks and feeding equipment that come into contact with your calves, like nipples and buckets.


2. Make gradual adjustments. You may have started feeding calves higher volumes of bulk tank milk due to supply chain issues associated with COVID-19, and it’s always a good idea to continue feeding extra milk. However, if your calves are currently on milk replacer, the shift to fresh milk can’t take place overnight. Avoid digestive upsets by slowly phasing the milk into calves’ diets over several days, making sure it is properly cooled, stored and pasteurized prior to feeding.

3. Consider feeding transition milk. Cows do not go straight from producing colostrum to producing milk. Instead, the second through fourth milkings are typically made up of “transition milk,” a nutritionally rich intermediate. By feeding calves transition milk across the first three to five days of life, you can provide additional nutrient support to their developing immune systems, potentially leading to greater gains and lower scours risks down the road.

Check calves regularly for signs of sickness

After you have taken steps to prevent scours, don’t forget to monitor calves twice daily during feedings for signs of sickness (e.g., loose stool, fever, depression, dehydration and weakness). Knowing what type of scours you are dealing with can help you identify which management changes are necessary for prevention.

Transitional scours typically occurs in 5- to 10-day-old calves, producing loose manure but generally no other clinical signs, and may be caused by inconsistent feeding practices. Infectious scours, on the other hand, may begin earlier or last longer than transitional scours, may involve additional symptoms like fever and depression, and may be caused by viral, protozoal or bacterial exposure within the calves’ environment or feed.

If you make adjustments to your calf management practices and are still seeing more than 15% incidence of scours or calves with unusual signs, there may be a more serious issue at hand. Team up with your veterinarian and nutritionist to run diagnostics, identify the problem, and determine what management steps you can take to reduce scours on your dairy.  end mark

References omitted but are available upon request. Click here to email an editor.


Doug Hammon
  • Doug Hammon

  • Senior Manager, Dairy Technical Services
  • Zoetis

Signs of Sickness

• Loose stool

• Fever

• Depression

• Dehydration

• Weakness