When calves are dehydrated and in need of electrolytes, what they need the most is the water in the electrolyte solution, according to Dave Wood, Director of Sales and Technical Support with Animix, Juneau, Wis.
Wood told the audience at the recent Vita Plus Calf Summit that mixing electrolyte powder with milk can cause excessively high osmolality that can delay nutrient absorption and possibly result in making the situation worse.
Noah Litherland, Dairy Youngstock Technical Specialist with Vita Plus, explained that excessive osmolality (or saltiness) of oral fluids can quickly dehydrate a young calf. Litherland said salty fluids pull water from the calf's tissues into its gastrointestinal tract and can cause diarrhea and dehydration. He said dehydration is a loss of water, electrolytes and oxygen, which can lead to increased clostridial growth. Litherland went on to explain that excessive osmolality also can slow the gut flow and "stall" the movement of nutrients in the intestines.
“The key to minimizing the risk of osmolality imbalance is to measure powder and water in order to accurately mix milk replacer according to label instructions,” he said. “Imbalances occur when too high solids (> 15% concentration) are fed or when calves do not have access to drinking water.”
Wood reported that during bouts of scours, the calf can lose 6 - 12% of its body fluids in one day, and that research shows that total body weight loss can reach 17.3%. He explained that much sodium and chloride is lost when calves experience diarrhea, and that electrolytes help replenish these vital nutrients.
It is Wood's opinion that electrolytes should be viewed as a strategic intervention -- not an ongoing adjunct -- to include continuously with whole milk or milk replacer solution for a short period of time. He encouraged presenting warm water (100 - 105° F) that contains electrolytes one hour or more after feeding milk or milk replacer, and offering electrolyte solution only to scouring calves or as a single dose to all calves after stress such as significant transport. Wood also encouraged limiting offering electrolyte in the water for concurrent periods of several days. He explained that if electrolytes are fed too long, sodium can build up in the calf's body and literally reverse proper osmotic balance, resulting in loss of body fluids.