Proper Milk Replacer Concentration Helps Prevent Clostridium
What is Clostridium?
Clostridium is a Gram-positive bacteria with around 250 species. One of the more prevalent clostridia in calves is Clostridium perfringens, and it is ever-present in both the animals’ housing environment and intestinal tracts.
Although healthy calves can co-exist just fine with clostridia, abrupt changes in diet or feeding schedule can disrupt the normal flow of milk through the abomasum, and cause an overgrowth of Clostridium perfringens. One of the most telling symptoms is sudden bloat on both sides of the belly, sometimes accompanied by scours, depression, and calves going off feed.
Once an infection is established, treatment is challenging. Calves sometimes die even before they develop scours, and even may fall into the frustrating scenario of “fine at one feeding, dead the next.”
Consistency is the cheapest and easiest way to prevent Clostridium perfringens infections. It usually takes a stressor to set off a problem. One of the bigger mistakes is the inconsistent mixing of milk replacer from one feeding to the next.
Here is a suggested protocol for proper mixing of milk replacer (MR):
Throw away cups. Depending on who is filling the cup and the density of the MR, the variance can easily be 2 oz. per scoop. In a 10-oz. feeding, that’s 20% variation.
Use a scale to measure MR powder instead.
Calculate the solids concentration (12.5% – 13.5%) desired for the mix.
Use a thermometer to measure temperature. Consistency from one batch to the next is critical.
Add hot water at minimum of 110˚F. If MR powder is cold, water temperature may need to be as high as 140˚F to achieve the desired feeding temperature of 105˚F.
Add the powder and mix for 1 minute. Use a whisk for small batches, or a mechanical mixer or power drill for larger batches.
Let solution sit for 1 minute, then mix again until all powder is in solution.
Add water to achieve desired volume and a feeding temperature of 105˚F.
All mixing and feeding equipment must be cleaned and sanitized after each use, and feeding times each day also should be consistent. In very cold weather, adjustments may need to be made so the “as fed” temperature of the MR solution does not drop below the calf’s body temperature of 102˚F.
Establishing mixing protocols is an important step to ensuring that each batch of milk replacer is formulated at correct and consistent solids concentrations, no matter who is preparing the MR solution. Calculating these concentrations can be a bit confusing, depending on whether a final volume of water (example: 2 quarts) is added to the powder; or if water is added to achieve that target volume. Either way is acceptable, but they will produce different solids concentrations if equal amounts of powder are used.
The calculation to determine solids is:
Weight of powder ÷ (Weight of powder + weight of water)
For example, mixing 10 ounces of powder with 2 quarts of water will result in approximately 2.2 quarts of solution that is 13.5% solids:
10 ounces of powder ÷ (10 ounces of powder + 64 ounces of water) = 13.5%
As opposed to mixing 10 ounces of powder in 2 quarts of water, which will result in approximately 2 quarts of solution that is 15.6% solids:
10 ounces of powder ÷ (10 ounces of powder + 54 ounces of water) = 15.6%
This demonstrates the importance of using a proper equipment to accurately measure the powder and water.
You can use a Brix refractometer as a cross-check to verify solids concentration in finished batches, but I recommend relying most heavily on the initial calculations. It is important to follow directions to ensure consistency and maintain digestive health. Inconsistent mixing of the ration puts the calf at risk to have digestive and clostridium issues.