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Why bio-availability of every nutrient in dog food is vital to your dog.

The science paper that I am reviewing  suggests that " Progress in the nutrition of companion animals requires more precise information on the requirements of cats and dogs at various physiological stages, bio availability of nutrients, interaction among nutrients and the role of various nutrients in the prevention of diseases."

Essentially it posits that the majority of food trails that the aafco dog food standards are based on are either inadequate, are outdated or were performed on other species.

The newer food trials often are not based on a lot of science because the research on bio availablity is very scant. There is a long held belief that plant sources are never going to supply your dog as good as meat sources will.

The reason that they posit this is the global dog food companies are so big and powerful that new trials are often done by themselves with inadequate external checks. They could not afford to find that dogs require meat based foods, so conveniently most studies done avoid these kinds of questions. This paper we critique does not hold back on giving you actual facts and data of the papers it could find.

This if often how the dog food trials are conducted:

" One approach to setting nutrient requirements is to determine the minimal intake of the nutrient that prevents clinical signs of deficiency. This value is useful to veterinary nutritionist for diagnostic purposes but should not be used as the minimal level in a practical diet." REF 1

"Deficiency signs appear when the stored nutrient is depleted, which is dependent on the extent of the body stores and the difference between the intake and requirement of the nutrient. Studies to determine requirements are generally of two types: depletion studies, where normal replete animals are given diets with various concentrations of the nutrient, and depletion-repletion studies, where the animals are first depleted of the nutrient and then given diets supplying various amounts of the nutrient. REF 1

"Two further important reasons why the minimal intake to prevent deficiency signs should not be used to set requirements are

1) a population of animals need nutrients in excess of minimal requirements to account for individual variation in the utilization of nutrients and

2) feed ingredients are biological materials that have biological variation in nutrient composition.

Note, in this paper this is only the beginning of their arguments against the current aafco table requirements.  And while they don't suggest grains should be banned, the later arguments on bio availability are pretty obvious. Your dog needs a lot more meat to just meet the minimum REAL requirements of dogs.

"Requirements for growth. What criteria were used to set the NRC nutrient requirements of dogs and cats? Most of the requirements for essential amino acids listed by the NRC (1985, 1986) for growing puppies and kittens were determined as the minimal in take of an amino acid that supported maximal rate of body weight gain or nitrogen balance.

This technique gives valid estimates WHEN the diet contains excess levels of all essential nutrients other than the one being studied and body weight gain and nitrogen balance have the same maxima. We have reservations that the diets used to determine the amino acid requirements of growing puppies by Milner and associates (Milner 1979, 1981, Burns et al. 1982) supplied nitrogen in excess of the puppies' requirements for maximal performance." REF 1

Its almost like the tables were created to allow as many loop-hole as possible to exist to ensure that dog food could be created with grains and vegetables to meet the requirement - even though they are often lacking in useability by a dog.  You will also note that every can and pack of dog food has a mass of vitamins and minerals added to them because grains and vegetables alone come nowhere near the requirements set in the tables.

Grains and vegetables also are not palatable to dogs in their raw form and have to be treated a great deal to make them edible often destroying nutrition in the process. The only reason that meat is included by dog food companies (besides branding purposes) is to reach the minimum amino acids requirements (as grains and vegetables fall well short).

How long do you want your dog to live?


"The appropriateness of the criterion of maximal rate of body weight gain to set the requirement is open to question. Longevity studies with rats and dogs (Headhammar et al. 1974, Kealy et al. 1992) indicate that maximal rates of gain are not necessarily compatible with maximal lifespan and optimal skeletal development. Cats and dogs are not usually raised for human food so the efficiency of food conversion is not relevant to these animals." REF 1

But it does turn out that if you feed your dog or cat a log of their product, that it will provide them with a lot more money for their shareholders. 

"Although reasonable values for the quantitative requirements of essential amino acids for growing kittens and puppies are published, the same does not apply to maintenance values for adult cats and dogs. There have been a number of studies on the amount of various proteins required for nitrogen balance in adult dogs, but virtually the only values on the quantitative amino acid requirements for maintenance are in a thesis by Ward (1976) that has not been published.

If you have read to this part of the page in my article, well done.  The whole deal with science papers by the dog food companies is to tell you over and over how good they are for your dog, and hide any of the boring science stuff. And rely on you never fiding these kinds of critiques of science papers or be too bored to try and read one 

 The fact that most dog owners just want to TRUST these multi nationals because they can't be bothered learning the science to properly assess their dogs diet, is what the big companies rely on.

Then also imagine if you decided that dog food based on vegetable matter was inadequate for your dog. What would you do with this information?  Would you give up the convenience of buying pre made dog food at the super market. Would you actively campaign against the makers selling this species inappropriate food?  

Most people don't want to have to see what evidence they would have to dismiss and how they would have to change their entire lifestyle. Imagine not trusting big business, unheard of  ?!

The following is a snippet of information on the MAIN REASON that I researched and suggest feeding your dog more meat.  If you don't do it through their main diet, then meat based dog treats like I sell on this site are a good alternative.   But please read on and decide for yourself.

Nutrient availability for your DOG

"A knowledge of the bioavailability of individual nutrients in dietary ingredients is essential for accurate and predictable formulation of nutritionally complete diets.

Estimates of the bioavailability of energy yielding nutrients can be readily accomplished with a digestibility trial and measurements of the energy values of the food and faeces. Similarly, nitrogen availability (apparent digestibility) can readily be measured, but apparent digestion coefficients of crude protein (nitrogen) are not necessarily the same as the availability of individual amino acids in the protein.

The amino acid composition of undigested food residues is modified in the gastrointestinal tract by bacteria, which both contribute and utilize amino acids, such that the faeces contain a mixture of unmodified food amino acids and amino acids of bacterial origin.

In addition, amino acids of low nutritive value, such as the dipeptides lysinoalanine and lanthionine, are absorbed and increase the apparent digestibility of nitrogen (Robbins et al. 1980)." REF 1 

Why is lysine (essential amino acid) vital to your dog?

"Lysine is of particular importance in canine nutrition because it is the first limiting amino acid in grains, and processing can decrease the availability of lysine. In the presence of reducing sugars and moisture, the free epsilon amino group of lysine forms a Schiffs base with the sugar and results in a product of lower digestibility than the entire protein. Therefore, the apparent digestibility of nitrogen may seriously overestimate the availability of lysine." REF 1

This is a long paper and as you can see these guys 'know their stuff'. I have to tell you that I dont know what a Schiffs base is, but I have read many times about the issue of limiting amino acids. This paper goes through many of the TEN essential amino acids that are required by humans and dogs alike to met our basic needs, let alone to excel.  What if dog food barely met the minimum levels because of issues like bio availably and limiting amino acids?  Imagine.

"Many studies have been done on the bioavailability of dietary minerals by various animals, but few of these studies used cats or dogs. Phosphorus in corn, soybean and other plant seeds is largely in the form of phytate (myoinositol phosphate) and is poorly available to simple stomached animals (ie dogs) (Reddy et al. 1982), some sources having a bioavailability as low as 0.3 ." REF 1  Meaning they would need three times teh amount to meet the minimum requirements)

"For most animals, the bioavailability of magnesium from plant sources is low, although the apparent digestibility approaches 0.5 for mineral sources of magnesium (Pastoor 1993). The efficiency of magnesium absorption is not constant but is inversely related to the level of phosphorus and calcium in the diet of cats."

Yes the above statement mentions cats, but much of this paper is also devoted to dogs. You can see how complex the interaction of just a few of these elements are.  Imagine how difficult it would be even if  input cost was no objection (and it definitely is to a dog food manufacturer) to formulate a diet based on inappropriate foods (vegetables) for what is basically a carnivore (dog).  IT WOULD BE VERY HARD, and expensive and would only be a shadow approximation of what a dog and wolf evolved to eat (meat). 

"Trace elements in natural feed ingredients are not fully available to animals consuming them, and there are virtually no values on availability pertaining directly to cats and dogs."  REF 1

Please note that after all the vitamins and minerals that have to be added to meet the minimum aafco dog food standards, come the trace elements, which by nature of the quality TRACE mean very small quantities. You might almost wonder what the point was in adding them, if the dog food companies didn't know that many of these trace ingredients are just trying to make up for what occurs naturally in meat based diets.

"Low bioavailabilities of zinc and copper in some of the feed ingredients have resulted in clinical signs of deficiencies of both these elements in cats and dogs.

Endogenous phytic acid is strongly implicated in the low bioavailability of zinc from many plant sources (Davies and Olpin 1979, Lei et al. 1993, Likuski and Forbes 1965). Phytic acid binds zinc more strongly than either copper or manganese. In contrast to plant products, the bioavailability of zinc in beef to chicks is high (Hortin et al. 1993).

Zinc deficiency has been reported in puppies reared on commercial diets (Huber et al. 1991). The relationship between high calcium and low essential fatty acid intakes and zinc deficiency has long been recognized in swine production. Zinc oxide often included in pet foods has a bioavailability of only 0.61 of zinc sulfate for chicks (Wedekind and Baker 1990, Wedekind et al. 1992). " REF 1

" Nutrients have functions in addition to providing nutrition The science of nutrition has evolved through three major phases: the delineation of essential nutrients, the determination of quantitative nutrient require ments and, currently, the elucidation of the effect of nutrient status on the genome, aging, immune status and incidence of diseases." REF 1

So as you can see, the science of concocting artificual food for your dog is quite complex, the studies incomplete and were base on maintiaint growth levels and not having dogs get too sick.  RARELY do they look at things like how it affects the genome, aging and immune status of dogs.  They are saying that while you can put a receipe to gether that seems to have all of the right amount of ingredients to sustain life,  bio availaibyt is usually copletly ingnored as are what the nutrieients in meate can provide for " genome, aging, immune status"  that plant matter can not (for carnivore dogs).

Fair Healthy Dog Treat conclusions

You might understand that since i am not a  food or nutrition scientist that I have merely cut and pasted a small proportion of this large speculative paper. I did this as these kinds of papers seem to get buried  rather quickly by the popular press, that often carry ads (in hard copy and online) for dog food companies (or their even more massive parent companies).

This paper does not PROVE with new research what is missing in dog food, but provide plenty of evidence from previous trials that their are many reasons to suspect that a meaet based diet is light years ahead of any grain or veggie based meal that dog food technicians can cobble together.

I would love to see primary research and funding for such research dedicated to showing the full value of a meat based diet for dogs and cats, but while big money talks, that will never happen. There is no money in proving the status quo wrong.

All I can suggest is that after reading these snippets that I have commented on, you check this paper and similar papers for yourself about the possible deficiency in commercial dog food diets.

My conclusion (the one that had me begin sourcing and selling meat based dog treats) is that meat from may different sources is always going to be healthier for your dog than from any lab. 

If you dont want to change your dogs diet (and all the habits and convenience of buying grain and veggie based dog foods from supermarkets or 'specialty retailers' then please consider supplementing your dogs diet with genuine quality meat based dog treats from stores like us.


REF  1 =  Assessment of the Nutritional Adequacy of Pet Foods - Through the Life Cycle

JAMES G. MORRIS  And Quniton ROGERS. Department of Molecular Biosciences, School of Veterinary Medicine, university of California, Davis,  California

You may notice that this paper was written in 1994 however most aafco information for dog nutrition still comes from 1985 !

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