Calf Oral Electrolytes
When a calf breaks with scours, it is critical to keep her hydrated with additional fluids until her scours resolve. In the worst cases where the calf becomes severely dehydrated, she will likely need IV fluids. But for mild and moderate cases, it is possible to keep her hydrated through oral electrolyte solutions (OES). Similar to Gatorade, OESs not only hydrate but replenish specific electrolytes that are lost in the diarrhea. Loss of electrolytes would cause the calf’s blood pH to drop below normal and become acidic (called a metabolic acidosis), resulting in a droopy, weak calf.
OESs should be fed in two extra meals to sick calves separate from their normal milk feeding. Offering just one extra meal is acceptable, but not ideal. Begin offering an OES at the first sign of scours and continue until scours resolve, which could take 6-8 days. Even if the label says you can, don’t mix the OES with milk: sick calves need the extra fluid volume, and adding OES powder can change the osmolality (or concentration) of the milk which can slow abomasal emptying, which results in an increased risk of bloat!
While there are tons of OESs on the market for calf scours, they’re not all the same. There are some very specific ingredients that are necessary for a good OES, and unfortunately the majority of products don’t have the most important one! Here’s what makes a good OES:
An alkalinizing agent is essential to correct the metabolic acidosis by countering the acidity of the blood with a base (alkaline) to neutralize the blood to a normal pH. There are three options for alkalinizing agents: acetate, propionate and bicarbonate. Acetate and propionate are the best of the three because not only do they correct the acidosis, but they produce a source of energy when metabolized, they stimulate water and sodium absorption in the intestines and they inhibit the growth of Salmonella and other bacteria by not changing the pH of the GI system. Bicarbonate will correct the acidosis but doesn’t do any of the other things and will actually raise the pH of the GI system, which encourages opportunistic bacteria to grow and cause trouble.
Acetate and propionate also contribute toward the other properties of a good OES. Sodium is one of the main electrolytes lost in diarrhea and it also helps with rehydration, so it must be replaced through the OES. Ingredients that facilitate intestinal sodium and water absorption are also necessary. The good alkalinizing agents already do this and are assisted by other ingredients like glycine or glucose. Another ingredient is any form of energy to correct a decrease in blood sugar from the fact that the calf’s intake is likely decreased. As mentioned above, acetate and propionate provide energy after they’re metabolized. Note that milk will always have much more energy than an OES, but a little energy will provide a boost until the next milk feeding. Too much energy in an OES changes the osmolality and has an increased risk of bloat, just like when an OES is added to milk. Finally, an OES should encourage a healthy GI by maintaining the correct pH in the GI which will discourage opportunistic microbial growth. Remember, bicarbonate can change the pH of the GI and encourage growth, while acetate and propionate will maintain the pH.
Manufacturers are constantly trying new ingredients in their OES to help the calves, but there are two that could be harmful. Psyllium is a form of dietary fiber used in humans and small animals with diarrhea. However in calves, it is thought to slow abomasal emptying, resulting in an increased risk in bloat, and studies have shown it doesn’t work. The other ingredient to avoid is anything rice-based. While common in human medicine, it will induce severe diarrhea in calves!
Even with this nice list of what should be in a OES, checking it against an ingredient label isn’t always easy. We’ve saved you the trouble and put together the chart below of the best, the acceptable and the OESs to avoid. The chart will also be on our website with a printable review sheet covering the basics of OES for quick reference. If your OES isn’t on the list, save the label for your next herd health or call and we’ll take a look. There’s a new product called Resoltz that is similar to Epic electrolytes and seems promising, but we haven’t had the opportunity to try it out. It will be added to the chart as we learn more, as will any new products.