The “ideal protein” concept is not ideal in animal nutrition

Welcome to discussions on this new paper regarding the “ideal protein” concept in animal nutrition. Thanks for your participation!

Although I agree with the author of the article about the difficulties of practical application of the ideal protein concept, nevertheless, I believe that this concept has the right to exist as a mathematical model. It can be used to get closer to the most efficient protein absorption. But in practice, fluctuations in the composition of grain raw materials and protein sources are observed, and the metabolism of animals and birds also differs both from the type of animals, and from age and various physiological stages. Therefore, the concept of an ideal protein in practice cannot be applied perfectly. As a biochemist, I believe that one should simply strive for the optimal ratio of amino acids. Typically, requirements for amino acids and other substances in the diet are developed by geneticists and breeders and are attached to the technological passport of the bird. This is the most important basic information to follow.

But animals can improve the ratio of amino acids and make this ratio closer to the theoretical model of an ideal protein using biochemical reactions for the synthesis of the desired amino acids, the degradation of unnecessary amino acids, and the transamination of amino acids. This requires specific conditions and cofactors, for example, coenzymes, electron donors and acceptors, necessary trace elements.

I should like also to comment from Dr. Marchenkov regarding "vegetable methionine". As Dr. Wu correctly states, methionine is methionine; an amino acid with a clearly defined structure INDEPENDENT of the source. I have seen numerous products claiming to be "Herbal methionine" and these materials are not methionine, and do not contribute methionine. When used in correctly balanced and formulated diets, they invariably result in reduced animal performance. They will only work in diets that contain an excess of methionine ie where supply is significantly higher than the bodies demand for methionine, whether for protein synthesis or other essential functions such as glutathionine production. So please; no more mention of "vegetable / herbal methionine".

Herbal methionines were introduced when there was a severe shortage of d.l.methioninine. herbal methionine is a powder which has comparatively higher level of methionine compared to other grains and cakes which are known to contain different levels. Some body analyzed the samples of herbal methionine sold in the market and found 3% d.l.methionine with the same test used for measuring the methionine content. When questioned, the herbal methionine suppliers are putting up a different theory. Their version is that herbal methionine works like d.l methionine. The component it contains cannot be measured in the same way as d.l.methionine is measured. But it gives same biological results as d.l.m but the action is not explained in scientific terms. The results out of herbal methionine are far inferior to synthetic d.l.m. many herbal.profucts are coming in to poultry feeding as growth promoters, immunity boosters and anti microbial. Ban on antibiotic feed additives and some times short supplies of synthetic amunoacids are leaving a place for these products. Number of suppliers are springing up and the performance should be tested before large scale application.

In my opinion, the problem is not with the producers n suppliers, problem is with the regulators, corrupt drug dept personal, govt agencies n research institutions, any product intended to be introduced in the market, needs to b analysed, studied, only if comparitve results obtained, be allowed to be introduced, as it affects the birds/ animal health n well being first n also enters the human food chain n has environmental impact. Regulators not doing their job must be punished along with the company or person introducing sub standard products in the market, our ineffective, inefficient n corrupt judiciary n govt depts be sentisised with the facts n procedures to ensure quality, effectiveness n economy

Just to put some pepper to the discussion, approximately 60% of the Methionine requirement from modern broilers comes from vegetable sources. Congratulation on the discussion about nonessential amino acids, that is truly great, and a better understanding of NEAA in the microbiota patterns are welcomed.