Electrolytes For Dairy Calves

Posted: December 5, 2005

Oral rehydration solutions are used to replenish fluids and electrolytes that are lost during the course of diarrhea. Also known as electrolytes, these solutions are a convenient way to treat calves with diarrhea.

There are many brands of electrolytes on the market that offer treatment for diarrhea through rehydration and electrolyte replacement. These products, however, can be variable and the right one needs to be chosen for each individual dairy.

Oral rehydration therapies are designed to improve acid-base balance by providing electrolytes and water. Although they are generally easy to use, neonatal calf diarrhea is still a major cause of death and economic loss in the dairy industry. According to the USDA, calf mortality averages 8.7% annually, of which 62.1% is due to scours. In past years, mortality due to scours averaged 60.5% in 1996 and 52.5% in 1991 indicating an expanding problem in the dairy industry.

Although convenient and easy to use, the capacity of oral rehydration use for treatment is limited when there is a lack of protocol on the farm. Farms should have a standard operating procedure for treatment of scouring calves that includes when to use oral rehydration solutions, how much to give and many other questions that can arise without proper protocol.

Calves can lose 5 to 10% of their bodyweight in water within 1 day of scouring. Fluid loss in excess of 8% requires IV treatment, and over 14% loss can result in death. This is why it is extremely important to monitor calves daily and treat them quickly when signs of illness are observed. The amount of water lost by scouring calves can approximated using symptoms such as skin tenting, gum condition, attitude, and ability to stand or suckle.

To evaluate hydration using skin tenting, pinch a fold of skin (best done on the neck) and count the seconds it takes to flatten. Flattening of skin in less than 2 seconds indicates normal hydration. If skin takes 2 to 6 seconds to flatten, the calf is about 8% dehydrated. Over 6 seconds indicates severe dehydration above 10%. Gums can be evaluated by looking at their color and feeling them for moisture. Normal gums should be pink and damp but if gums are white and dry this indicates 8 to 10% dehydration. One of the best measures of estimated dehydration and illness in calves is their attitude during milk feeding. Calves may show no symptoms of dehydration but if they need encouragement to drink, monitor them closely for scouring or other illnesses.

Different ways currently exist for feeding milk or milk replacer while feeding oral rehydration solution to scouring calves. One way is to cut milk out completely and only feed oral rehydration solution for the entire treatment period. Another way is to only feed the oral rehydration solution for 2 days then feed half and half with milk the last day. And the third way is to feed the rehydration solution and milk as well in separate feedings.

Calves need enough energy to maintain their weight as well as their immune system, especially when they are sick. Oral rehydration solutions cannot provide enough energy because they are limited in the amount of glucose that can be added in order to keep the osmolarity of the solution low. Therefore, feeding milk or milk replacer supplies more energy and protein, allowing calves to maintain weight.

If scouring becomes a regular occurrence a veterinarian should be consulted to determine the source and whether antibiotics are appropriate. Also, a few fecal samples should be taken and sent to a diagnostic lab to evaluate the cause of enteric infection. This may help establish a preventative program and save time and labor in treatment of scouring calves.

For further information on this topic see the mimeo Electrolytes for Dairy Calves in the Penn State Dairy Nutrition Web pages at

Sylvia Kehoe, Graduate Student and Jud Heinrichs, Professor of Dairy and Animal Science, Department of Dairy and Animal Science