Thursday, December 12, 2013

The Most Common Mistake in Mixing Milk Replacer

The most common mistake when mixing milk replacer is to measure out the final volume of water and then add milk powder.
Disclaimer: If you milk milk replacer powder for one calf at a time and each calf consumes the total amount of mixed product, then these comments do no apply to you.

For all of us that mix a large volume of milk replacer and then feed a fixed volume to each calf, this potential error applies to YOU.

I visited a farm yesterday to help confirm that the mixing protocol was correct. Their goal is to feed 15 percent solids. 

Their protocol using a mechanical mixer that both mixes and delivers the reconstituted milk replacer is to add water until they have about one-half of the desired volume. Then they add the total amount of powder for the mix. After this is blended more water is added until the selected mark on the side of the stainless steel tank is reached.

Actual numbers? Run in 35 gallons of water. Add 85 pounds of powder. Blend. Add enough water to come to 65 gallons total mix. 

Total mix weighs 559 pounds (that is, 65 gallons X 8.6#/gallon = 559).
Total powder added was 85 pounds. 
When total powder is divided by total weight (85 / 559) we get .152 or 15.2 percent solids.

Great! Now when they feed 6 quarts of this daily the calves receive just about 2 pounds of solids a day   (6 quarts = 12.9 pounds "as-fed" at 15.2% solids)

The most common mistake in mixing milk replacer?

Measuring the total volume of water equal to the amount of mix desired and then adding powder to that water. What would have happened if this calf care person had not followed the correct protocol? She would have started by filling her mixer with 65 gallons of water. 
Then she would have added the 85 pounds of milk replacer powder. What would have been the result?

Well, she started with 65 gallons of water. At a little over 8.3#/gallon that comes to 542 pounds. Then added 85 pounds of powder. Total weight now is 627 pounds.

When total powder is divided by total weight (85/627) we get 13.5% - not the intended 15% solids. So when she feeds 6 quarts of this 13.5% mix daily the calves receive 1.74 pounds of powder each day.

Does a mixing error make a difference?

So what? There is not much difference between 1.74 and 1.96; only .22 pounds. But, in a week that comes to over 1.5 pounds less feed. 

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