The minimum percentage of taurine in wet cat food (canned cat food) should be 0.2% and in dry cat food it should be 0.1%. Put another way, there should be a minimum level of 1000 mg taurine per 1 kg of diet in dry cat food and a minimum of 2000 mg per 1 kg of canned cat food.
The information comes from the Association of American Feed Control Officials, official publication (1997) as referred to in the book: The Cat Its Behaviour, Nutrition & Health by Linda P Case.
Going online, I can confirm that the above figures are correct as per the Association of American Feed Control Officials (AAFCO) PDF file official publication “proposed revisions edited per comments for 2014”. This document is described as the AAFCO Methods for Substantiating Nutritional Adequacy of Dog and Cat Foods.
The AAFCO website does not have a search facility. I discovered this document online using Google. As you can see it’s quite current at 2014. And the numbers square up with the information from Case’s book of 1997.
The figure of 0.2% per canned and 0.1% the dry cat foods, “Presumes an energy density of 4000 kcal ME/kg as determined in accordance with Regulation PF9. Formulations greater than 4000 ME/kg must be corrected for energy density as is the case for formulations less than 4000 kg ME/kg.”
ME stands for metabolisable energy. For commercial foods, the statement of calorie content is often located on the back or sides of packaging and is expressed as ME (kcal/kg) = X; where X will be a number such as 4000. 4000 kcal ME/kg means there is 4000 kcal per 1000 g of food.
Reason for the difference between wet and dry cat food
As is obvious, there is a distinct difference between the required taurine content in wet and dry food. The taurine requirement for cats eating canned food is twice that of cats consuming dry foods. It was found that the reason for this is that the protein in canned products was damaged by heat processing. This led to the production of indigestible protein byproducts which in turn are fermented by intestinal microbes. These microbes proliferate in the intestines and degrade taurine.
I hope this helps.
Some more information on taurine
It is an essential nutrient which is synthesised by cats from two amino acids: methionine and cysteine. It is required for many aspects of the cat’s metabolism. It’s important in bile acid conjugation and to digest fat. Taurine is also required for the function of the retina for normal eyesight and is necessary for the normal functioning of the myocardium.
Taurine is in animal tissues. Fish, poultry and meat have high concentrations. A carnivorous diet provides a domestic cat with an adequate taurine intake. Conversely a diet containing high amounts of plant products and cereal grains may not provide sufficient quantities of taurine. Domestic cats can synthesise only small amounts of taurine and need a dietary supplement of it for a balanced diet.
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