WildAgain Wildlife Rehabilitation, Inc.

Milk replacers for wildlife
Scooping or weighing - which is better?


One of the issues with some of the powdered milk replacer products is that the powder is uneven and inconsistent, and the particles show a tendency to clump together. This makes it difficult to accurately measure the powder volume with a scoop. WildAgain's lab tests show a relatively high degree of variability, averaging around +/- 5%, but in some cases as high as almost 20%. Since rehabilitators are striving for accurate measurements when making formula, is it better to use a scoop and measure volume  - or use a scale and measure weight?

Measuring by volume  (using a scoop)

Many rehabilitators use a scoop to measure milk replacer powder prior to mixing as it is easy and quick. The scoop used can vary in size from a teaspoon, tablespoon, a cup, or even larger, depending on how much formula is being made at a time. When the powder is very fine in texture and consistent between different lots (such as the Fox Valley products), this approach to measuring can generally produce consistent and repeatable results.

Measuring by weight  (using a scale)

However, when the powder is uneven and inconsistent in texture (such as some PetAg products), using the volume or scooping method can produce considerable error, especially where fine measurements of components, such as proteins and fats, are desired. For these types of products with high variability in texture, measuring by weight will yield a more consistent amount of powder to be mixed into a formula.

There are many scales available. Scales that measure in grams are preferred since they are able to be more precise. A digital scale is desirable since the amounts can be easily read. It is nice to have a digital scale that measures in precision to tenths of a gram if weighing small amounts, such as milk replacer powders or very small animals. Regardless of type of scale, it is important for it to be accurate. There are many types of inexpensive digital scales available, including from online sources.

For those not familiar with using a digital scale, the photos below provide an overview of the process.

Figure 1. The powder can be placed on a small piece of wax paper and then weighed on the scale. In this case, the amount of powder on the scale weighs 6.5 grams, which is equal to 1 tablespoon of the powder. Figure 2. If the scoop is to be used in measuring and then using a scale, it is important to know the weight of the scoop. In this case the scoop weighs 3.1 grams. Figure 3. Here the scale has been adjusted, or "tared" to compensate for the weight of the scoop. Once this is done, then the scale will then show only the weight of the powder. In this case, the powder weighs 6.5 grams. Figure 4. If the scale used does not have a tare function, then simply weigh the scoop (as in Fig.2), then weigh the scoop filled with powder, and subtract the weight of the scoop. In this case, 9.6 minus 3.1 equals 6.5 gr.

What should the milk replacer powder weigh?

For products and lots listed on this website. All of the lots tested by WildAgain have 1 tablespoon weights associated with them, as determined by WildAgain's tests. All of the calculated component analysis values presented on this website are based on those weights. So using those same weights of powder and mixing 1:2 are expected to produce the same component values for those lots.

For products and lots not listed on this website. The best suggestion is for the first 2-3 measurements from a can or bag, weigh each of them, try each in a proven formula recipe, and if successful results are seen, then use that weight as the standard for that bag. If successful results are not seen, then add or subtract slightly from the weight and try again to establish a standard weight for that bag or can that produces successful results in a formula. This is especially important for any milk replacer powders that have a pronounced tendency to compact in the bag or can, and having lighter weight volumes at the top and heavier weights at the bottom. For those products with the tendency to compact, such as some lots of PetAg milk powders, the compaction can be somewhat compensated for by turning or rolling the bag or can multiple times between each time the powder is used.

Clearly measurement by weight is a more time consuming procedure, but it can help reduce measurement error from mixing and using formula made with a powdered milk replacer.


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