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Be proactive in using electrolytes to raise healthy calves

Dr. Julian “Skip” Olson for Progressive Dairy Published on 03 July 2019
Calf feeding

Electrolytes are a staple of successful calf-raising. If we were to make a list of necessities for raising healthy calves, electrolytes would be on it. 

Why are electrolytes so important? Electrolytes play an integral role in rehydrating calves that have lost fluids from stress or sickness, like scours. They also provide supplemental nutrition and correct metabolic acidosis that frequently accompanies scours.



Electrolytes can have a positive impact on calf health when used proactively and correctly. Here are 10 tips to successfully incorporate electrolytes into your calf program.

1. Use proactively 

Electrolytes can give calves a supportive boost ahead of stress events. Examples include extremely hot or cold weather, temperature fluctuations, moving to new housing, transportation and procedures such as castrating, dehorning or vaccination. 

Some dairies choose to support every newborn calf by feeding them electrolytes for the first one to three weeks of life. Other dairies in hot climates feed all pre-weaned calves electrolytes during midday. When using these proactive strategies, choose an electrolyte supplement versus treatment. For simplicity, you may be able to use a treatment product, but more diluted than the prescribed treatment rate. Work with your veterinarian or nutritionist to determine the best strategy for proactively managing hydration and health for your calves. 

2. Check for essential ingredients

An electrolyte powder should contain:

  • Sodium: Replenishes systemic salts and promotes water absorption to re-establish extra-cellular fluid volume

  • Glucose (dextrose): Provides energy, helps maintain body condition and assists with water absorption

  • Glycine: Helps absorb sodium, glucose and water

  • Alkalinizing agents: Such as bicarbonate, acetate or propionate – help reduce metabolic acidosis

  • Other electrolytes: Potassium and chloride – replenish lost systemic electrolytes commonly seen with diarrhea

Keep in mind that water is the most important component of electrolyte solutions. When calves are affected by a virus or bacteria, their intestine’s ability to absorb water is often compromised. The addition of sodium, glucose and glycine help calves absorb the liquids and restore fluid loss.


3. Feed in addition to milk 

Calves need adequate nutrition, particularly during times when they also need electrolytes. Even the best electrolyte solution cannot replace milk or milk replacer. There is evidence that milk can also serve as a source of hydration as shown in the beverage hydration index (BHI) – a ranking of beverages for human hydration.

When using a standard score of 1 for water, the BHI ranked whole milk at 1.50, equivalent to oral rehydration solutions. While the BHI is for humans, we may be able to extend this hydrating benefit to calves by using milk or milk replacer to maintain hydration, in addition to feeding electrolyte solutions.

4. Allow time between feeding milk and electrolytes 

Some alkalinizing agents found in electrolytes, such as bicarbonate, will interfere with the formation of casein curd and decrease acidity in the abomasum. It is thought that casein curd formation helps slow the passage of whole milk into the intestine, allowing more complete digestion of proteins in the abomasum. A lower pH in the abomasum forms an acidic barrier to bacteria and helps prevent pathogens from entering the intestine. Avoid feeding electrolyte solutions right after whole milk to prevent this interference. If you’re feeding milk replacer, it’s likely a non-issue because milk replacer is often void of casein. 

Another concern with feeding the milk ration and electrolyte solutions too close together is the impact on osmolality, the measure of concentration of particles in a kilogram of solution. If osmolality gets too high (greater than 600 mOsm per kilogram), calves cannot process the solids, causing a delay in passage through the abomasum. This can result in bloat and digestive tract damage. For both reasons, wait at least one hour between feeding milk or milk replacer and electrolyte solutions.

5. Do not combine electrolyte powder and milk or milk replacer

Creating dangerously high osmolality levels is a risk when combing electrolyte powder with milk or milk replacer. For example, whole milk has an osmolality of about 300 mOsm per kilogram and is typically about 12.5% solids. If you add 4 ounces of an electrolyte powder to 4 quarts of whole milk, the resulting total solids would be about 15%. Adding that same electrolyte powder volume to 2 quarts of whole milk would result in a total solids of 17.5%. 

Don’t run the risk of feeding a high-solids solution by adding electrolyte powder to whole milk or milk replacer. If you do, it is mandatory the calf has access to fresh water and it drinks enough to counteract the high-solids feeding. 


6. Feed the appropriate dosage for the calf’s size and condition 

Begin feeding electrolytes at the first sign of stress, dehydration or scours. Mildly dehydrated calves have already lost 5%-8% of their bodyweight in a day or less. They will show signs of lethargy or mild depression, sunken eyes and dry mucous membranes and poor appetite, but will still suckle. Calves with dehydration less than 8% can usually be treated with electrolytes.

The next step is to determine the amount of fluids lost by multiplying the calf’s bodyweight by its estimated percent dehydration, then administer that volume of electrolyte solutions. 

Example for a 100-pound calf that is 6% dehydrated: 100 x .06 = 6 pounds of water lost

One quart of water weighs about 2 pounds, so the calf would need 3 quarts of electrolyte solutions daily until its condition improves. Remember, the calf still needs to maintain its milk intake of at least 10% of bodyweight per day along with fresh water.  

Dehydration over 8% usually requires the calf to receive fluids intravenously. These calves are very depressed and lose their desire to suckle and stand.

7. Follow the same sanitation practices for feeding the milk ration

Just as you take great care to clean, sanitize and dry equipment for feeding calves milk or milk replacer, the same applies for electrolytes. This equipment includes pails, whisks, bottles, nipples and esophageal feeders. Because calves receiving electrolytes may already be stressed or sick, you don’t want to introduce more harmful bacteria into their systems or spread it to healthy calves being fed electrolytes proactively.  

8. Store electrolyte powder to protect quality 

Like milk replacer, electrolyte powder should be stored in a cool, dry environment to prevent moisture accumulation and caking. Use dry utensils to scoop electrolyte powder and carefully seal multiuse containers between uses.

9. Consider buying in bulk 

The cost savings between purchasing individual packages of electrolytes and bulk packaging can be significant. Buying in bulk can sometimes cut the cost per dose in half or more. But you will have to weigh the cost savings with your rate of use. Bulk packaging should be resealable or stored in a sealed container to minimize moisture accumulation.    

10. When in doubt, feed it out 

Aside from the cost, there is little detriment in overfeeding electrolytes as long as they are adequately spaced between milk feedings. If you are questioning whether to continue feeding electrolytes for another day, err on the side of generosity, and administer another feeding.

Just as oral rehydration therapy was called “potentially the most important medical advance of the 20th century” by The Lancet, electrolytes for calves play just as important of a role. Using electrolytes as a preventative tool can get calves back on track for healthy gains and performance.  end mark

PHOTO: Some dairies choose to support every newborn calf by feeding them electrolytes for the first one to three weeks of life. Other dairies in hot climates feed all pre-weaned calves electrolytes during midday. When using these proactive strategies, choose an electrolyte supplement versus treatment. Staff photo.

Julian “Skip” Olson
  • Julian “Skip” Olson, DVM

  • Technical Services Manager
  • Milk Products LLC
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