To soy or not to soy - that is the question!

[Egg Blues]

) I still don't want to use Soy, because I heard soy contains phytoestrogens which are said to cause _____ by acting like human estrogen.

I agree with almost all of what you are saying here. Birds, chickens included, have a much stronger stomach acid than humans do, and they are able to more completely break down proteins as a result. That's what our stomach acid is mostly for--proteins. We have enzymes in our saliva for starches/carbohydrates, and we have bile from the liver for the fats. We don't typically eat rocks for our minerals (I get a few in my rice), but chickens' stomach acid is of such a level as to partially or even fully digest the rocks they eat, which also function in their gizzard as teeth to help crush their food.

That bit about gluten was interesting and new information to me. Thank you.

All that said, I wanted to comment on the phytoestrogens being similar to human estrogen. I believe there is an effect here which impacts humans (not necessarily chickens). I live in Asia where soy is one of the staple foods, being consumed as soymilk, tofu, soy sprouts, soybean curd, soy sauce, fermented soy paste, etc. Whereas in America where meat is heavily consumed and men are aggressive and masculine and even women seem to want to be men, in Asia, the opposite trend is observable: men are more effeminate, weaker, and few can grow a full beard--and the men often want to be women (e.g. ladyboys). It appears that there is a strong correlation between diet and the hormonal system (endocrine system). It would be interesting to see the results of a double-blind study in which an experimental group of Caucasians were fed an Asian diet and vice versa, to counter genetic differences, and see if the results would be quantifiably significant.

Back to the chicken feed proteins: I think you meant to be saying "lysine" was higher in soy instead of "methionine". It's my understanding that methionine has to be added to soy proteins (supplemented) in order to make them more digestible, because soy is naturally low in methionine [LINK TO NATURE ARTICLE]. I've noticed, however, that some articles online seem to say soy is high in methionine while others say it is low. I'm wondering if this is in the domain of a popular error that has yet to be dispelled.

 

[U_Stormcrow]

Very interesting. I am learning a lot.
Thank you for sharing.
I thought that one of the big anti-soy rationales was environmental. Apologies if I missed it, but I don’t think you addressed that concern.
Also, I am curious, I have been using a soy-free feed with grub based protein. Their label has the same % methionine as the Purina food. How does that happen if soy is the only practical source?

I didn't address environmental because A) it has nothing to do with nutrition, on which I am barely qualified to comment;
and B) because in my experience posters concerned with environmental rationales often seek nonGMO (at minimum) or Organic, not merely an absence of Soy.

So I guessed at the questioner's intent.

I am familiar winth only one grub-based protein source commercial chicken feed brand - Grubblies. I've commented on them in other posts. In answer to your question, see my answer "6" - Animal Based Proteins. Grubs is Animals. Grubs are also high fat, which is reflected on Grubblies nutritional label. Unlike other feed companies, Grubblies have tried hard to avoid ending up with an extremely high fat feed as result - by starting with wheat, not corn, then peas (high protein, low fat), then grubs, calcium, barley, oats, flax seed (another high relative methionine but also high fat source), then alfalfa meal (lower protein similar amino acid profile to soy - its another legume). So what did they give up??? COST. Grubblies is roughly 4.5x more expensive than the feed I use.

My feed (NOT nonGMO!) is 24% protein (vs grubblies 16%), 4.5% fat (G 5.0%), 6.0% Fiber (G 8.0%), 1.3% Lysine (G 0.75%), 0.5% Methionine (G 0.4%). I pay $16.change for 50#. Grubblies is $83 for 60#

 

[RoyalChick]

I didn't address environmental because A) it has nothing to do with nutrition, on which I am barely qualified to comment;
and B) because in my experience posters concerned with environmental rationales often seek nonGMO (at minimum) or Organic, not merely an absence of Soy.

So I guessed at the questioner's intent.

I am familiar winth only one grub-based protein source commercial chicken feed brand - Grubblies. I've commented on them in other posts. In answer to your question, see my answer "6" - Animal Based Proteins. Grubs is Animals. Grubs are also high fat, which is reflected on Grubblies nutritional label. Unlike other feed companies, Grubblies have tried hard to avoid ending up with an extremely high fat feed as result - by starting with wheat, not corn, then peas (high protein, low fat), then grubs, calcium, barley, oats, flax seed (another high relative methionine but also high fat source), then alfalfa meal (lower protein similar amino acid profile to soy - its another legume). So what did they give up??? COST. Grubblies is roughly 4.5x more expensive than the feed I use.

My feed (NOT nonGMO!) is 24% protein (vs grubblies 16%), 4.5% fat (G 5.0%), 6.0% Fiber (G 8.0%), 1.3% Lysine (G 0.75%), 0.5% Methionine (G 0.4%). I pay $16.change for 50#. Grubblies is $83 for 60#

Thanks. It isn’t Grubblies but it certainly is expensive!

 

[U_Stormcrow]

Back to the chicken feed proteins: I think you meant to be saying "lysine" was higher in soy instead of "methionine". It's my understanding that methionine has to be added to soy proteins (supplemented) in order to make them more digestible, because soy is naturally low in methionine [LINK TO NATURE ARTICLE]. I've noticed, however, that some articles online seem to say soy is high in methionine while others say it is low. I'm wondering if this is in the domain of a popular error that has yet to be dispelled.

Nope, I absolutely meant to say Methionine.

Here's the popular error. BOTH are Right. and BOTH are Wrong. Wait, what???
They are using different measures. First, I want you to imagine a table full of desserts. One of those desserts is a pie. That pie is called "protein". The other desserts are fat, carbs, fiber, salt, calcium, etc.

And like one of those multiflavor cheesecake pies you can buy in the grocery store, every slice of that pie is a different amino acid. Now because all proteins aren't the same, some have bigger slices of some flavors (amino acids) than others. Their relative value differs.

Plenty of sources say that grains and pastas are high in Methionine.

As a percentage of their total protein, they are. Here's the slices of our protein pie from wheat (soft wheat, hard "red" wheat is similar. Due to rounding errors, adds up to less than 100%):

Here is the amino acid profile for Soy Meal (the most common way soy appears in chicken feed, for Reasons) (g/16g N is another way of writing % protein - and due to rounding errors, it adds to more than 100%)

And here is the common bean (kidney, great northern, etc):

Looking carefully at the chart, wheat's 1.5% methionine looks better that soy meals (probably rounded up) 1.4%, looks better than kidney beans lowly 1.1%. In terms of relative sive of the slices of the protein pie, you are correct.

Now, here's where that's wrong. WE DO NOT CARE what % of the protein is methionine. We care only about how much methionine the chicken gets in its diet.

Wheat averages around 12.6% protein on a dry matter basis. 1.5% (Met content of protein) of 12.6% total protein of 87% (dry matter) is .16g of Methionine in 100g of wheat. (the target number we are looking for is at least .35).

The common bean is given an average protein level around 24.8%, again, on a dry matter basis. 1.1% of 24.8% (protein) of 89.1% (dry matter) is .243g Met per 100g of beans.

and Soy meal? 1.4% of 49.5% (the average protein in LOW protein soy meal - there are higher protein varieties available) of 87.5% (dry matter) is 0.606g Met per 100g of low protein soy meal.

Even if we "correct" for rounding errors by adding 10% to the Met content of the wheat, and taking 10% from the Met content of the soy meal, the soy remains a far better source for Met than does the Wheat.

So how is it that the ingredient with the largest (relative) slice of Met in its pie has the smallest contribution of Met to the diet? Because Wheat is a low protein source - its a small pie. A big (relative) slice of a small amount is still a small amount. Beans are a moderate protein source, though the relative size of the Met slice is somewhat smaller, the pie itself is roughly twice as large - so it provides more Met in a serving of equal weight. And soy meal? Yes, its not the biggest slice, but it IS the biggest pie - and thus provides the most Met by weight.

Make sense???

as an aside, this is why people look at the protein content of the feed, in the assumption that higher total protein % means greater chances of meeting desired amino acid minimums (assuming they are aware of them).

 

[U_Stormcrow]

And the Study you linked? Its a true thing, but stated in a way that leads to confusion and erroneous assumption. They compared soy protein to meat protein on a gram per gram basis. Animal meats are all complete proteins, and while there is a little variation, they largely are made up of amino acids in roughly similar proportions. While soy is one of the few "complete" proteins in the vegetable world, its profile of amino acids (the relative slices of the pie) are not the same.
Compared to other plants, its a good methionine source. But its a fantastic lysine source. So when you look at its ration of Met:Lys, it looks pretty bad.

Using feedipedia's numbers, 1.4:6.2 = 22.5% Use the same source for wheat, 1.6:2.9 = 55.2% The ratio of the two is better in wheat, in part because its a louse source for both, pound per pound.

Feeding chickens doesn't involve giving them just one ingredient (unlike the study), or comparing three diets based on pound per pound substitutions of one ingredient for another - which tells you as much about the rest of the diet as it tells you about the ingredient in question. Part of the reason making a chicken feed at home is so hard is because there are so many variabes that need to be balanced - or at least the minimums met, with any excess being waste.

The poor rats failed to grow because their minimum methionine levels weren't being met, so most of the other amino acids (like lysine) they were getting was being wasted.

The ratio of the limiting amino acids in chicken feed (there is some room for reasonable difference in opinion based on study consulted, breed, age) is something close to 4:9:7:2 Met:Lys:Thr:Tryp

That ratio in the protein of soy meal is approx 4:19:11:4. Relative to the Met levels, there is an excess of Lys, Threonine, and Tryp.

in wheat? 4:7:7:3 Relative to Met, there's a shortage of Lysine and an excess of Tryptophan

Beans? 4:23:15:5 Excess of Lys, Thr, and Tryp.

Corn? 4:6:7:1

That's part of why feeds are blended from multiple plant sources, often with a mix of grains, legumes or pulses, seeds, and other ingredients - attempting to more closely balance high nutritional value (and frequently higher expense) ingredients with much cheaper ingredients whose nutritional deficits are covered by the excesses of others. This both reduces cost and reduces waste. But you still have to meet the minimums - it doesn't do a lot of good to get the AA profile right if it doesn't provide enough of anything...

Its made more complicated, because we can't use just the protein from soy, or meat, or casein from milk (4:12:7:2, btw) the way the study did, we have to use substantially the whole ingredient.

[going to compound rounding errors here - but its rough back of napkin math]

So if you mix equal amounts of soy meal, wheat, and corn protein (plus all the rest of their components, of course), your ratio looks like 4:10.6:8:2.6 - we want 4:9:7:2 to not waste anything - that's not bad, which is part of why its such a popular blend in chicken feeds. We balanced it by averaging their proteins. Using the proteins to determine relative weights, the soy meal is about 50% protein, the wheat about 12.5%, the corn maybe 10%. So 1 part soy meal, 4 parts wheat, 5 parts corn.
That gets you in the right area, at least.

Now you have to consider fat levels, fiber levels about a dozen vitamins, minerals, trace nutrients, calcium, non phytate phosphorus, anti-nutritional factors in your ingredietns (soy needs to be heat treated, for instance) and you can pretend to know something about chicken feeds.

Simple, right?

 

[NatJ]

I live in Asia where soy is one of the staple foods, being consumed as soymilk, tofu, soy sprouts, soybean curd, soy sauce, fermented soy paste, etc. Whereas in America where meat is heavily consumed and men are aggressive and masculine and even women seem to want to be men, in Asia, the opposite trend is observable: men are more effeminate, weaker, and few can grow a full beard--and the men often want to be women (e.g. ladyboys). It appears that there is a strong correlation between diet and the hormonal system (endocrine system). It would be interesting to see the results of a double-blind study in which an experimental group of Caucasians were fed an Asian diet and vice versa, to counter genetic differences, and see if the results would be quantifiably significant.

Just look for families that moved from one country to another, had children, and raised those children on the typical diet of the place they moved to. Moving doesn't change someone's genes, but it usually does change what foods are available. No need to set up a special study of controlling diet in childhood.

Of course this would be more accurate for measurable physical traits (height, weight, body composition, beard.) It may not tell you anything useful about behavior, because the different social environment also affects behavior.

If you know anyone from your area who moved to America, and raised children there, or who moved from America and raised children in your country, you might start by looking to see if their children look obviously different. If the diet makes a really big difference, it will be obvious even with a very small sample size. If the diet makes a small difference, you probably won't notice much.

About beards specifically, I always understood there to be a big genetic component, no matter what the diet. But I've read that height, weight, and body composition can be heavily influenced by diet (with some diets stunting growth, while others allow the full expression of the person's genes for size.)

 

[3KillerBs]

@U_Stormcrow Thank you for doing all that math for those of us who can't (really *can't* -- math-related LD).

 

[My Very First 6 Chickens]

@U_Stormcrow

And the Study you linked? Its a true thing, but stated in a way that leads to confusion and erroneous assumption. They compared soy protein to meat protein on a gram per gram basis. Animal meats are all complete proteins, and while there is a little variation, they largely are made up of amino acids in roughly similar proportions. While soy is one of the few "complete" proteins in the vegetable world, its profile of amino acids (the relative slices of the pie) are not the same.
Compared to other plants, its a good methionine source. But its a fantastic lysine source. So when you look at its ration of Met:Lys, it looks pretty bad.

Using feedipedia's numbers, 1.4:6.2 = 22.5% Use the same source for wheat, 1.6:2.9 = 55.2% The ratio of the two is better in wheat, in part because its a louse source for both, pound per pound.

Feeding chickens doesn't involve giving them just one ingredient (unlike the study), or comparing three diets based on pound per pound substitutions of one ingredient for another - which tells you as much about the rest of the diet as it tells you about the ingredient in question. Part of the reason making a chicken feed at home is so hard is because there are so many variabes that need to be balanced - or at least the minimums met, with any excess being waste.

The poor rats failed to grow because their minimum methionine levels weren't being met, so most of the other amino acids (like lysine) they were getting was being wasted.

The ratio of the limiting amino acids in chicken feed (there is some room for reasonable difference in opinion based on study consulted, breed, age) is something close to 4:9:7:2 Met:Lys:Thr:Tryp

That ratio in the protein of soy meal is approx 4:19:11:4. Relative to the Met levels, there is an excess of Lys, Threonine, and Tryp.

in wheat? 4:7:7:3 Relative to Met, there's a shortage of Lysine and an excess of Tryptophan

Beans? 4:23:15:5 Excess of Lys, Thr, and Tryp.

Corn? 4:6:7:1

That's part of why feeds are blended from multiple plant sources, often with a mix of grains, legumes or pulses, seeds, and other ingredients - attempting to more closely balance high nutritional value (and frequently higher expense) ingredients with much cheaper ingredients whose nutritional deficits are covered by the excesses of others. This both reduces cost and reduces waste. But you still have to meet the minimums - it doesn't do a lot of good to get the AA profile right if it doesn't provide enough of anything...

Its made more complicated, because we can't use just the protein from soy, or meat, or casein from milk (4:12:7:2, btw) the way the study did, we have to use substantially the whole ingredient.

[going to compound rounding errors here - but its rough back of napkin math]

So if you mix equal amounts of soy meal, wheat, and corn protein (plus all the rest of their components, of course), your ratio looks like 4:10.6:8:2.6 - we want 4:9:7:2 to not waste anything - that's not bad, which is part of why its such a popular blend in chicken feeds. We balanced it by averaging their proteins. Using the proteins to determine relative weights, the soy meal is about 50% protein, the wheat about 12.5%, the corn maybe 10%. So 1 part soy meal, 4 parts wheat, 5 parts corn.
That gets you in the right area, at least.

Now you have to consider fat levels, fiber levels about a dozen vitamins, minerals, trace nutrients, calcium, non phytate phosphorus, anti-nutritional factors in your ingredietns (soy needs to be heat treated, for instance) and you can pretend to know something about chicken feeds.

Simple, right?

Yea, simple!

 

[leah vanity]

Here's an interesting article I found about a study on sources of methionine for organically fed poultry...

https://portal.nifa.usda.gov/web/cr...f-methionine-for-organically-fed-poultry.html

It's relatively recently too

 

[leah vanity]

And the Study you linked? Its a true thing, but stated in a way that leads to confusion and erroneous assumption. They compared soy protein to meat protein on a gram per gram basis. Animal meats are all complete proteins, and while there is a little variation, they largely are made up of amino acids in roughly similar proportions. While soy is one of the few "complete" proteins in the vegetable world, its profile of amino acids (the relative slices of the pie) are not the same.
Compared to other plants, its a good methionine source. But its a fantastic lysine source. So when you look at its ration of Met:Lys, it looks pretty bad.

Using feedipedia's numbers, 1.4:6.2 = 22.5% Use the same source for wheat, 1.6:2.9 = 55.2% The ratio of the two is better in wheat, in part because its a louse source for both, pound per pound.

Feeding chickens doesn't involve giving them just one ingredient (unlike the study), or comparing three diets based on pound per pound substitutions of one ingredient for another - which tells you as much about the rest of the diet as it tells you about the ingredient in question. Part of the reason making a chicken feed at home is so hard is because there are so many variabes that need to be balanced - or at least the minimums met, with any excess being waste.

The poor rats failed to grow because their minimum methionine levels weren't being met, so most of the other amino acids (like lysine) they were getting was being wasted.

The ratio of the limiting amino acids in chicken feed (there is some room for reasonable difference in opinion based on study consulted, breed, age) is something close to 4:9:7:2 Met:Lys:Thr:Tryp

That ratio in the protein of soy meal is approx 4:19:11:4. Relative to the Met levels, there is an excess of Lys, Threonine, and Tryp.

in wheat? 4:7:7:3 Relative to Met, there's a shortage of Lysine and an excess of Tryptophan

Beans? 4:23:15:5 Excess of Lys, Thr, and Tryp.

Corn? 4:6:7:1

That's part of why feeds are blended from multiple plant sources, often with a mix of grains, legumes or pulses, seeds, and other ingredients - attempting to more closely balance high nutritional value (and frequently higher expense) ingredients with much cheaper ingredients whose nutritional deficits are covered by the excesses of others. This both reduces cost and reduces waste. But you still have to meet the minimums - it doesn't do a lot of good to get the AA profile right if it doesn't provide enough of anything...

Its made more complicated, because we can't use just the protein from soy, or meat, or casein from milk (4:12:7:2, btw) the way the study did, we have to use substantially the whole ingredient.

[going to compound rounding errors here - but its rough back of napkin math]

So if you mix equal amounts of soy meal, wheat, and corn protein (plus all the rest of their components, of course), your ratio looks like 4:10.6:8:2.6 - we want 4:9:7:2 to not waste anything - that's not bad, which is part of why its such a popular blend in chicken feeds. We balanced it by averaging their proteins. Using the proteins to determine relative weights, the soy meal is about 50% protein, the wheat about 12.5%, the corn maybe 10%. So 1 part soy meal, 4 parts wheat, 5 parts corn.
That gets you in the right area, at least.

Now you have to consider fat levels, fiber levels about a dozen vitamins, minerals, trace nutrients, calcium, non phytate phosphorus, anti-nutritional factors in your ingredietns (soy needs to be heat treated, for instance) and you can pretend to know something about chicken feeds.

Simple, right?

This is a great discussion guys! I have been researching methionine since yesterday haha