WildAgain Wildlife Rehabilitation, Inc.


Milk Replacer product tests (6) – June 2013

PetAg’s® Esbilac®(2) & KMR®, plus Fox Valley’s® 20/50,  32/40, &  40/25

 

 

Highlights

WildAgain's research on milk replacement powders used with juvenile wild mammals in rehabilitation is a continuing longterm project. The following includes a summary of recent findings and observations, discussed in more detail below, including potential impacts when the powders are used to make formula for wild mammals in rehabilitation:

  1. Some of the milk replacement powders from 2012 -13, including Esbilac® and KMR®, are remarkably lighter in weight on a dry matter basis, which could lead to underfeeding of nutritional requirements.

  2. The increasing inconsistency of the texture of the products has caused greater measurement variability ranging from 20-30% when using the scoop measurement method. This fact, coupled with the previous point above (1), inadvertent underfeeding could be as high as almost 30%.

  3. The percent values of nutritional components continue to vary, with noticeable increases in protein values.

  4. The ingredients of two recent lots of Esbilac® tested are remarkably different, especially the secondary ingredients. It is unclear if this, plus some reformulation of the primary ingredients, is causing the noticeably different color of the powder, or if it is due to another change in the manufacturing and/or drying process.

  5. Chronically low levels of certain micro minerals continues to be an issue in some Fox Valley Animal Nutrition and PetAg products, primarily Copper and Manganese, even to the point of being undetectable in some of the samples.

  6. Probiotics have been added to Esbilac® powder since December 2012. However, there are questions about the extent to which the low levels provide measurable therapeutic value.

 

Product testing

The products tested include PetAg’s® Esbilac® (lots HG2182E and H3532E) and KMR® (lot H0713K), as well as Fox Valley’s 20/50 (lot 43282), 32/40 (lot 10413), and 40/25 (lot 20103). Testing methodology was identical as testing conducted on previous milk replacer product samples and as described on this website. Results are posted on this website, accompanied by the Midwest Lab proximate analysis of nutrient values and macro and micro minerals.

 

Finding #1 – PetAg® Esbilac® and KMR® weight (dry) is lower than recent years

The table below indicates that the dry powder weights of Esbilac® and KMR® have changed significantly, in the range of 20-23% less than prior lots tested in the last 2-3 years. The Fox Valley® products have remained more consistent over time. The current values can be quickly compared with prior years on the web page that provides this data for all products that WildAgain has had tested. The impact of this is that if the powder is being scooped to measure rather than weighed, the wet matter basis shows nutritional composition values of the fully reconstituted formula will be significantly lower than in prior years. For the PetAg® products tested, this weight variance can be in excess of 15% less than in recent years.

So while the milk composition analysis shows that the milk powders are meet the Guaranteed Analysis for protein and fat, the energy (kcals) are lower when mixed with the specified amount of water. A more in-depth discussion of these tests and the measurement error that can be introduced by scooping the dry products rather than weighing them is provided at the following link web page that presents this topic in more detail.

Table 1. Scooped weight in grams per tablespoon (large end of the PetAg® red scoop).

 

Finding #2 – Product texture (dry) is more coarse/inconsistent than prior years

The table below indicates that the dry powder texture and consistency of Esbilac® and KMR® have changed towards being more coarse, clumpy and inconsistent, in the range of 20-30% more than prior lots tested in the last 2-3 years. The Fox Valley® products have changed significantly over time, especially for 32/40 and 40/25, with changes in the 100-200% range. This is surprising for the Fox Valley® that have remained quite consistent in recent years. The current values for these products can be quickly compared with prior years on the web pages for each of the products that WildAgain has had tested.

The impact of this texture change is that if the powder is being scooped for measurement (rather than weighed), the wet matter basis shows nutritional composition values of the fully reconstituted formula will be significantly lower than in recent years. For a more in-depth discussion of these tests and the measurement error that can be introduced by scooping the dry products rather than weighing them, please visit the web page that presents this topic in more detail.

The term 'Standard Deviation' is used in the table below. Simple stated, this statistical measure indicates the value to be expected 68% of the time, or just over 2/3 of the time. So by example from the table for Esbilac® (2013), when the powder is measured by scooping rather than weighing, any given scoop can be 7% either above or below the average weight for the scoop. This degree of error can be completely eliminated by weighing the powder rather then scooping.

Table 2. Average standard deviation of scooped weight in grams per tablespoon (large end of the PetAg® red scoop). Statistically, the standard deviation represents the percentage that the scooped weight will vary plus or minus from the average. A higher standard deviation number means less accuracy when measuring the product by scooping rather than weighing.

 

Finding #3 – Nutritional composition is similar to recent years

The table below indicates that the products tested have remained mostly consistent from recent years in the dry matter composition of protein and fat. The one exception noted was the protein has dropped about 5% in Fox Valley® 40/25 (see yellow shaded area below). All other products are within about one percentage point from prior years, which is in within normally sample test measurement error.

Another observation, as noted in the other yellow shaded numbers in the table, is the continuing excess of certain nutritional values over guaranteed minimums. These excesses should be taken into account when analyzing the nutritional composition of a wet matter formula. All of the products tested in this report have been added to the WildAgain Nutritional Calculator for such purpose.

Table 3. Percent values for the protein and fat content of the dry powder. Plus comparisons of variations from the Guaranteed Minimum values for protein and fat.

 

Finding #4 – Esbilac® has different ingredients and color

The figure below shows noticeable differences in the color of two separate lots of Esbilac manufactured about 5 months apart during 2012. This could be a result of differences in ingredients and/or changes in the manufacturing or drying process used for each lot. Additionally, the table indicates significant changes in the formulation of the two lots, in both primary and secondary ingredients. Manufactures have a history of regularly changing ingredients - and even the sources of the ingredients to improve products, reduce costs and so forth. While such changes may be beneficial, WildAgain has not assess the changes and cannot comment on them at this time  - other than to mention that there seem to be substantial changes in ingredients and prominence.

 

Table 4 (at left). Comparison of the primary and secondary ingredients of the same two lots of Esbilac® pictured above. In addition to the many secondary ingredients showing changes between the lots, the December 2012 lot also includes the inclusion of various probiotics, discussed in more detail below. It is unknown if the changes in ingredients (both primary and secondary) are responsible for the significant  color differences noted above, or perhaps resulting from changes in the spray drying process, which has occurred in the past. The blue highlighted ingredients indicate changed ingredients between the two lots. The ingredients are listed in the order they appear on the label, which usually indicates degree of prominence in the powder. In other words, since it is listed first for both lots, there is more vegetable oil in the product than any other ingredient listed.

Figure 1. Two cans of Esbilac® powdered milk replacer manufactured in August 2012 (left, Lot#HG2182E) and in December 2012 (right, Lot#H3532E) showing noticeable color differences. The powder in can on the left weighs approximately 8% more than the powder in the can on the left (in average scooped weight) and results in a slightly higher standard deviation error when scooped.

Figure 2. Close up view of the same two cans of Esbilac® powdered milk replacer manufactured in August 2012 (left, Lot#HG2182E) and in December 2012 (right, Lot#H3532E) showing noticeable differences in color.

Finding #5 – Certain micro minerals remain low or absent

As with prior lots tested of Esbilac® and various Fox Valley® products, levels of certain micro minerals remain at very low dietary levels. Notably, tests by Midwest Lab, a certified independent laboratory, show copper is low or not detectable in Fox Valley® products. Dietary copper is is very low or not detectable in Esbilac®. Deficiencies in these minerals can affect growth and energy levels. Some rehabilitators have developed formula recipes to meet the nutritional composition analyses of milks of wild mammals by combining PetAg® and Fox Valley® milk powders to achieve minimum levels of copper and manganese.

 

Finding #6 – Probiotics have been added to Esbilac®

The photo at right shows a change in the Esbilac® can labeling that indicates that probiotics have been added to the powder.

There seem to be a number of key questions that need to be addressed  to understand more about the probiotics that are mixed in with formula fed to a specific species in wildlife rehabilitation:

  1. What are the specific strains of bacteria that are normally present in the gastrointestinal tract of the species being fed? Is the probiotic a good match?

  2. Does the animal need supplemental probiotics on a recurring, routine basis, and why?

  3. What instances/conditions would suggest that probiotics be added to the diet? Which ones and how much? Should they be mixed with food or administered separately?

  4. What types of probiotics are beneficial to the species being fed? And in what concentrations/dosages? How often?

  5. What types of probiotics might prove harmful to the species being fed? And in what concentrations/dosages? Are there side effects or potential problems? If so, what problems are possible and what are the consequences/risks?

  6. Does the product have enough CFU's (Colony Forming Units) of the organisms to exist during the shelf life of the product, and to pass through to the intestinal tract when fed as viable organisms? Does storage or preparation affect the probiotics? How?

  7. Are there other and possibly more effective alternatives to products containing probiotics, such as preparing an innoculant from the stool of a healthy animal from the same species?

Interestingly, common milk replacer products commercially available and that have been tested in the past by WildAgain contain added probiotics. Presumably those manufacturers leave the decision to administer probiotics separately from including in the primary food product.

 

The table below shows the probiotics and concentrations (CFU's) for several commercially available products for small animals. As can be seen, there is no consistency on which specific probiotics are included, as well as no consistency on concentrations in the products. Most research studies do indicate that a recommended therapeutic dose is in the range of 1-4 Billion CFU's which is far above what Esbilac®, Bene-Bac™ and some of the other products provide. The research also indicates that the true beneficial health effects of probiotics are real, but knowledge of the specific types and concentrations is still evolving.

 

As for the user concerned about Esbilac® now containing probiotics, the research and table below raise questions about the benefits of the relatively very low concentrations. WildAgain and others will continue to explore the the issue of probiotics for wildlife in the future.

Table 5. Ingredients (and associated health benefits) and concentrations (CFU's) of certain commercially available probiotic supplements for small animals.

 

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