WildAgain has had a variety of tests conducted on the powdered milk replacer products from several of the major manufacturers. The tests performed include a proximate analysis (solids, protein, fat, ash) and mineral analysis (macro and micro minerals). For fat, the acid hydrolysis test was performed to more accurately assess the fat value. In some cases, a Peroxide Value test was performed to test for rancidity. The information from these tests was also used to calculate the component values for the liquid formula once reconstituted.

Midwest Laboratories in Omaha, performed the tests on the milk replacer powders listed below (except for the calculated values for carbohydrates, Ca/P ratio, kcals, and mineral percentages on the bottom chart). More information on Midwest Labs is presented below.

WildAgain also compared the mineral content of the various milk replacers. Unfortunately, there is limited information available on the nutrient requirements of many wild mammal species. As a result, WildAgain decided to use information published by the National Research Council in the Nutrient Requirements for Laboratory Animals, 4th edition (1995) as a guide. While the required amount of minerals for other species is likely to vary somewhat, the levels listed for laboratory rats may be considered a general range for other rodents, including squirrels. WildAgain compared the test results provided by Midwest Labs to the target minimum mineral level required for rodents as per the National Research Council. The results are in the chart below. One hundred percent (100%) is the target minimum level for rodents.

While the tested levels of some of the micro nutrients exceed the the targeted minimum levels for rodents, it is unclear to what extent the juvenile wild rodents or other mammals would be digesting, absorbing, or utilizing the trace minerals and the affect. Several of the milk replacers contained micronutrients that did not meet the minimum requirements for laboratory rats. It is very difficult to know what levels of these micronutrients are needed for different species and age of wild animals! Rehabilitators, nutritionists, veterinarians and others will want to further explore this information and decide if and how it affects juvenile wild mammals of various species that are fed these products.

It should also be noted that it is extremely difficult for a rehabilitator or other user to know the appropriate level and be able to adjust the extremely tiny amounts of trace minerals of the type needed in a milk replacer. Supplementing a milk replacer powder by adding a micronutrient could result in adding too much -- and cause toxicity, e.g., excess copper could result in liver and kidney damage, and more. Further research and consultation with professional nutritionists and veterinarians knowledgeable about and experienced with wild mammals is essential.

Analysis of mineral content (for 33/40 type milk replacers used for squirrels)

Midwest Labs

Testing of all product samples referenced in this document was arranged through Midwest Laboratories in Omaha, NE. Midwest Labs has serving the agricultural, industrial, environmental, and sampling needs of the United States and Canada for over 30 years.  Government agencies, such as the USFDA and USDA and official laboratory inspection teams regularly audit them to verify accuracy and quality of their procedures.  An extensive list of their qualifications and certifications is provided on their website. Midwest’s staff consists of over 100 scientists, lab technicians, clerical assistants, and administrative officers, housed in over 80,000 square feet of laboratory and support area. 

Pet food testing

Rehabilitators who wish to have any food products tested may contact certified independent laboratories. While such facilities may be found on the internet, there are benefits from asking nutritionists, food scientists and others about specific facilities. Since services, certifications, qualifications, experience, and prices vary, it is worthwhile to consider all of these factors rather than just selecting a lab that is nearby or less expensive.

Those interested in having tests conducted by Midwest Laboratories should call Sue Ann Seitz (Client Service Representative) at 402-334-7770 or email her at sueann@midwestlabs.com to establish an account. A sample of about 2 cups is required for powdered milk replacer products. Midwest will provide reduced cost UPS labels upon request for shipping. Once received, testing generally takes about 3-5 days with results provided quickly via email and later by U.S. mail. A variety of ingredient and microbiology testing is available, as listed on their website at www.midwestlabs.com. Contact Midwest for current pricing.