new research debunks trad views on nutrition

[U_Stormcrow]

Excess Protein is largely excreted as nitrogen compounds daily. Its not something birds store well (unlike excess dietary energy as fat) - which is why getting the right balance of AAs daily is more important than getting the minimum amount of calcium or dietary energy (as two common examples) every single day - because they are biologically better at averaging out daily variation in energy intake (and to lesser extent, Ca intake) than they are protein (and more important than CP, specific AAs. Other AAs birds can produce on their own, or repurposes (sometimes in reversible process) from other AAs.

The importance of Met, Lys, Tryp, Thre (and a few others needed in very trace amounts) is that chickens can't produce enough of them on their own to meet their daily needs, and that while Met can be repurposed as two other SAA (sulfur containing Amino Acids) to make up for shortages of those, the process can not be reversed by the chicken. and because Met is the first AA in protein formation, a shortage of Met means excess AAs of all other sorts are simply wasted (and largely excreted as N) over the course of the day, assuming they aren't used for energy.

The desire to control waste N (ammonia/urates) and cut down on the amount of chicken "stuff" being hauled out of commercial operations helped drive the "Ideal protein" theory. Also to optimize input costs.

 

[Labsandchickens8]

Excess Protein is largely excreted as nitrogen compounds daily. Its not something birds store well (unlike excess dietary energy as fat) - which is why getting the right balance of AAs daily is more important than getting the minimum amount of calcium or dietary energy (as two common examples) every single day - because they are biologically better at averaging out daily variation in energy intake (and to lesser extent, Ca intake) than they are protein (and more important than CP, specific AAs. Other AAs birds can produce on their own, or repurposes (sometimes in reversible process) from other AAs.

The importance of Met, Lys, Tryp, Thre (and a few others needed in very trace amounts) is that chickens can't produce enough of them on their own to meet their daily needs, and that while Met can be repurposed as two other SAA (sulfur containing Amino Acids) to make up for shortages of those, the process can not be reversed by the chicken. and because Met is the first AA in protein formation, a shortage of Met means excess AAs of all other sorts are simply wasted (and largely excreted as N) over the course of the day, assuming they aren't used for energy.

The desire to control waste N (ammonia/urates) and cut down on the amount of chicken "stuff" being hauled out of commercial operations helped drive the "Ideal protein" theory. Also to optimize input costs.

What is the minimum methionine requirement?

 

[U_Stormcrow]

Some reading.

 

[Shadrach]

Excretes at least some of it based on the components of manure. And the different compositions of manure relative to diet.

It must contribute to her fat percentage at some level.

 

[U_Stormcrow]

What is the minimum methionine requirement?

Depends on age, breed, purpose. In the case of dual purpose birds (barely studied), we have to make educated guesses.

In general, based on a 100g diet, a Met inclusion of 0.3% is the old recommend for an adult production hen under commercial condition in her prime production period (generally, first two adult lay cycles - something less than 2 years of age. From that, you can calculate about .3g of Met daily (so a bird consuming 150g of feed a day could meet that w/ a Met inclusion rate at 0.2%, etc).

More recent studies suggest somewhat higher rates of inclusion to maximize production, and their needs as adolescents/hatchlings are higher (as a rate of inclusion, because their rate of consumption is lower). That is, they eat less, and thus need a more nutritionally dense feed during their prime growth period.

If near peak production and near optimal health potential are less of a concern, hitting that target daily is commensurately less important. The more your bird looks and produces less like a meat bird or a production layer, (that is, the more your bird breed looks like a thin, infrequent layer of small eggs) the lower that need is likely to be (though again, its not studied). The older your bird is, the less critical that number is likely to be.

 

[Shadrach]

What is the minimum methionine requirement?

It depends on how many eggs the hen lays to some degree. A 0.2.5% to 0.4% are a representative range in the feeds available in the UK. I think the large commercial farms tend to feed at the higher end of the scale.

U_Stormcrow beat me to it.

 

[U_Stormcrow]

It must contribute to her fat percentage at some level.

Yes, this is absolutely true - but that fat can't be turned back into critical AAs, just used to meet energy needs.

 

[saysfaa]

It must contribute to her fat percentage at some level.

I expect so. I suspect that might have more to do with their bodies needing the amino acids and their derivatives to process the other nutrients in their diets than directly converting protein to energy or fat. Similar to needing Met to utilize all the other amino acids. That distinction may not matter. Or it may matter if the chickens have choices and select different foods or different proportions, or are given different formulations if they don't have choices. Something will be the limiting factor.

I haven't looked for this specifically; it is just a feel from looking at a lot of other physiology. Much of digestion and utilization is controlled by enzymes. Enzymes are made up of proteins. At least generally.

 

[Iluveggers]

A further problem is commercial feed is digested at a faster rate than wholegrains, some vegetables and higher fiber foods and this makes the hen eat more because she feels hunger earlier than a hen eating unprocessed (natural?) foods.

Much like in humans, an apple or two will satiate you quickly and digest slowly, applesauce may take a bit longer to feel full but move through faster , and apple juice will not make you full and will go right through. Nothing else added, just the amount it is broken down.

As far as amino acids, I’ve been taking “Essential Aminos” supplement in the morning, and it is amazing how long I can go before getting hungry for breakfast.

So much similarity between human and animal nutrition. I’m not well versed on the animal nutritional needs, but have done a lot of research on human nutrition.

 

[Shadrach]

Yes, this is absolutely true - but that fat can't be turned back into critical AAs, just used to meet energy needs.

Exactly, and having that contribution to fat that isn't going anywhere fast particularly if the hen is contained doesn't seem a great idea to me.