(From Another Article On Bottle Feeding Wild Exotic Cats)
Off-The-Shelf Milk Replacers
The most commonly used commercial milk formulas to bottle-feed exotic cats in the US are those produced by PetAg. Many use their KMR or Esbilac formulas because they are readily available and opinions are pretty much evenly split as to which works best in exotic cats. When one prefers one over the other, it is usually because they think they see less diarrhea and bloat with one or the other product. Some straddle the fence by use a mixture of the two. Everyone has occasional problems with both. When problems occur, it appears to be due to the fat portion of the formulas.
Because results have been mixed when either KMR or Esbilac is used in wildlife, PetAg also sells a line of Milk Matrix products that are milk-fat free the way all their products once were manufactured. The fat and oil portion of Milk Matrix formulas is all from vegetable sources. Of this line, their Milk Matrix 33/40, 42/25 and 42/50 are suggested. The first number in the names of these products represents their percentage of protein and the second the percentage of fat. I have not noticed that any one of these three Milk Matrix formulas gives consistently better results than another. Individual exotic cat professionals each have their favorite and which one you will personally find best is not predictable. That is probably because it is not so much, which one you feed, as how you feed it that makes most of the difference. Differences between product batches and limited product shelf life probably account for the rest of the differences you will see.
Most people purchase these formulas in dry powdered form. The process by which PetAg and the other Borden clone company, Fox Valley, include a fat or oil in a dry powder formula is a difficult one. Think about it. Have you ever considered turning a stick of butter into a powder? These products are, by their nature, very unstable with a short shelf life. They also vary from batch to batch because bulk dairy ingredients they purchase to make them are not a uniform product. During storage, milk-based formulas often become rancid and irritating as they form unhealthy peroxides and aldehydes (malondialdehyde, hexanal, alkenals) and loose vitamin E, other anti-oxidants and essential omega fatty acids.
It is not just the quality and freshness of the fats in dry formulas that is important. It is very important that the size of the fat droplets in the formulas you prepare be such that the cubs can easily absorb them. If the powdered formula you purchase is old or if that particular batch was not up to quality, or if the liquid you prepare was not blended sufficiently or was blended too vigorously, the fat can form lumps that are too large for infant exotic cats to absorb. When this occurs, the cubs can die from intestinal blockages. the milk fat ingredients (creams) they use to produce feeding formula seem more prone to this problem than their vegetable fats ingredients. Be sure there are no lumps, clumps or graininess in the formulas you prepare and that the powder itself shows no sign of off-odor or rancidity. I have tried various ways of keeping these powders fresh but haven’t been happy with any. The stuff just seems to have a mind of its own.
To be used successfully, all dry formulas needs to be well blended with pre-warmed water. The fat portion of KMR and Esbilac were reformulated some years ago to include milk fat. Changes were also made in the way the products were manufactured. So old formulas and advice you read about are no longer valid. Unfortunately, a lot of product information that might be helpful are company trade secrets. Each time a change occurs, it has lead to major confusion when their products are used to raise wildlife. The older formulas of KMR and Esbilac are still available from PetAg as Milk Matrix 42/25 and 33/40 respectively.
PetAg says that their Milk Matrix line has only vegetable fats, so the clumping of milk fat should not be a problem when you use them. However, PetAg put out an advisory a while ago that electric blenders, when used to vigorously, might cause the fat portion of their products to clump and congeal. They suggest the formulas only be mixed in blenders with intermittent pulse bursts. The characteristics of the fats in these commercial formulas are as important as their source. When fat or oil globules are the wrong size, they can lead to constipation and death in big cat cubs due to intestinal blockages. Cow-source butterfat in these formulas caused this problem at a number of large zoos and wildlife centers. This butter fat clumping problem does not seem to occur when you make your own formula using heavy cream.
You also have the option of purchasing similar products from Fox Valley or Wombaroo Food Products but, as far as I know, they all face the same production challenges.