From:
pjdutche@email.unc.edu
Date: 2003-04-17 14:01:02 UTC
Subject: RE: [ferrethealth] taurine (was RE: Hypoallergenic Diet)
To: ferrethealth@smartgroups.com
Message-ID: <13637843.1050588062749.JavaMail.root@scandium>
Author wrote:
> Hi Pam, it must be pretty low as canned cat food used to be processed at
> around 212 degrees F and didn't they find they had to add taurine after
> a lot of cats had health problems. I thought vitamins and taurine were
> damages well below the boiling point of water. Chris.
Chris, that definitely seems to be what is generally believed. I'm looking some things up and finding some conflicting info... I'm waiting to receive two articles from interlibrary loan right now that might help: one is about the taurine content in common food items that supposedly found some different results than earlier research with cooking food and taurine content; and one about how ferrets make bile acids (this is involved with high taurine requirements in cats). I'm hoping that between those two, I'll learn something. It'll take a little while for those to arrive and then to read them.
In the meantime, I found a couple of interesting web pages that give some figures for taurine content of raw vs cooked meat:
http://www.serve.com/BatonRouge/taurine_chmr.htm
http://www.felinefuture.com/fact/nutrition/taurine.html
http://www.holisticat.com/c_and_c.html
Note that boiling causes the most loss; however, in the case of people who make chicken gravy, the water is usually used in the recipe, and I found somewhere else that said that using the water would replace a lot of taurine lost in boiling. However, I for one make gravy with a pressure cooker and so might destroy more tuarine with that extra heat from the start than many people do. I don't know if the same would hold true for baby food - don't know how it's made.
Anyway, ferret nutrition expert Dr. Tom Willard kindly answered some of my questions and gave me permission to post the following:
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As far as the melting temperature of taurine as it relates to being destroyed during cooking, the two are unrelated. The melting temperature of a pure substance in the lab has little to do with its physical durability in a feed or as an integral part of a whole protein as is taurine. During extrusion, the moisture in the food does not get below 25% until the drying stage, which is at a lower temperature plus a higher air volume, which prevents loss of nutrients. This moisture protects the nutrients and minimizes the denatureation and loss. Canned
foods, which include baby food in jars, undergo a much higher temperature and longer time of cooking than dry foods, which will impact many of the nutrients especially the vitamins.
Now, getting to home made diets. There may be times where making a diet using baby food meats would be helpful but this must be supplemented with vitamins, minerals, fats and proteins to properly balance the food. Most individuals and a majority of the veterinarians do not have the ingredients or the know-how to do this on an ongoing basis while getting the ferret to eat it. This is especially true with ferrets since there is little published information on their nutritional needs. The other important factor in making a homemade food is how digestible are the ingredients used? The meats in baby food I am sure are well digested by ferrets but they may be deficient in some essential amino acids unless a variety of meats are used.
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SO - here we have an answer that would indicate that we DO need to be concerned with supplementing taurine in ferrets that are fed long-term on baby food or on other cooked meat home-made diets. How long is long-term in this case? I don't know. However, Dr. Kawasaki's article about retinal atrophy mentions that he fed a taurine-restricted diet for 3-4 weeks and noted significant retinal changes at that time. So, maybe a month or so? Or sooner if you are worried about it.
One round-about and tangential note regarding heart health. In cats with cardiomyopathy caused by taurine deficiency, it is a reversable condition if taurine is given. Taurine doesn't reverse it in ferrets, at least not commonly, according to something I read in either Fox or Hillyer and Quesenberry. Hmmmm.
Personally, I'm going to continue supplementing my ferrets' gravy with taurine. I don't think anyone knows the precise figure for dietary taurine in ferrets, so all's I know to do is keep looking at indirect evidence.
In any case, I'll post again when I receive those articles...
Best wishes,
-Pam S.