Does anyone have a good chicken feed spreadsheet they will please share?

[LaurenRitz]

For anyone who has tried harvesting it:
How did you get it out of the water?
Did you drain it before spreading it out to dry? If so, how?
Did you have other things (such as algae) in the water? If so, did the duckweed need to be separated?
How much did you spread it out?
How fluffy is it in the windrows?
Did you need to turn it?
Did you dry it in sun or shade?

Even though my climate is probably not as dry, it would help to hear how it goes for other people.

I just used a rake. The mat was thick enough that the individual size of the plants was meaningless.

Tipped the bucket over until the water stopped draining

No algae. The duckweed was too thick for that.

Spread it out on chain link. Turned it a couple of times.

At 100+ F and 0 humidity sun or shade is meaningless. Partial shade.

 

[LaurenRitz]

I'm curious as to why so many studies measure methionine and cysteine as one item? When they do this the methionine numbers jump much closer to the ideal.

 

[LaurenRitz]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9817926/

This page has some information and nutrients tables concerning broiler hens.

From the quoted study: Tannins, which can bind proteins and cause reduced digestibility, have been detected in some studies [12,13]. However, their appearance in duckweed could not be related to any anti-nutritional effect and decreased amino acid digestibility.

 

[saysfaa]

I'm curious as to why so many studies measure methionine and cysteine as one item? When they do this the methionine numbers jump much closer to the ideal.

Met and cysteine are the two amino acids that have sulphur. For many years after much was known about the other amino acids, researchers still had trouble distinguishing these two from each other. So they have a long, strong history of being lumped together. Possibly, it is still expensive to differentiate them (not sure about that part).

Also, they are intertwined with each other functionally. Each is required but the body can use one to make the other (edit: but only one way - I couldn't remember which way when I wrote this) at least to some degree. How much depends on things like the nutrient make up of the rest of the diet, the species in question, probably the age and health of the individual, probably other such things.

 

[Chickeeaholic]

Why do they say to keep it below 5%? Even at 40% protein, that's not going to make much of a difference in your protein levels.

I read so many articles yesterday, I’m trying to find which one said that. I will try to find it. I believe it was the fiber content but I’ll keep searching to find it.

 

[U_Stormcrow]

Met and cysteine are the two amino acids that have sulphur. For many years after much was known about the other amino acids, researchers still had trouble distinguishing these two from each other. So they have a long, strong history of being lumped together. Possibly, it is still expensive to differentiate them (not sure about that part).

Also, they are intertwined with each other functionally. Each is required but the body can use one to make the other, at least to some degree. How much depends on things like the nutrient make up of the rest of the diet, the species in question, probably the age and health of the individual, probably other such things.

^^^^^ This is largely correct. The ability to measure Met directly is relatively new compared to measuring other AAs, most old studies (and some newer) will instead reference SAAs - Sulphur containing Amino Acids. It still requires specialized equipment, and commands a price premium, albeit much less than it once did. One common lab charges an extra $120 to measure Met in addition to crude protein, starch, etc (for which it charges $30 or $40), but only an extra $145 to measure most of the key AAs including Met.

My only quibble is that while most critters (including chickens) can turn Methionine into Cysteine relatively easily, most critters can NOT effectively re-methylize Cysteine in the process of turning it back intho Methionine. There are some bacteria that can do it and its common in plants. However, more complex animals just don't do it well.

Of course, the same difficulties in measuring Met directly also mean there is more than the usual variation in the actual Met needs of birds, so I tend to look at Met levels first (a little more is better) and then Lysine, while proponents of the Ideal protein theory tend to look at Lys first, and then ratios based on Lys levels (the theory developed before Met's operation was well understood and its presence measured effectively).

 

[TooCheep]

Your final feed (assuming you are making a standard 100g ration feed) should be at least 0.3% Methionine and 0.65 or 0.7% Lysine. That means, functionally, the ratio of Met to Lys should be roughly 3:7 (approx 1/2 for those who haven't had coffee yet). This is "ideal protein" theory - it has some caveats, some big assumptions, but a basic understanding is useful at a high level. In duckweed, the ratio is roughly 1:5. Meaning you get a LOT of Lysine for every bit of Methionine - wasted Lysine (and by extension, wasted crude protein), unless something else in the diet is a huge Met source.

Now, that said, as a pea substitute, it has similar ratio (about 1:6 actually) and some similar concerns, particularly with the tannins. Your various cowpeas are closer to 1:5 also have tannin concerns, and others.

No perfect solutions, merely tradeoffs.

Hey @U_Stormcrow-
I have an alternate point of view and wanted to run it by you. You seem to be coming from the point of view that prioritizes balancing nutrients trying to come as close as possible to an ideal mix. Makes sense as it minimizes cost, input quantities and waste. Definitely makes sense for commercial feed producers and large chicken operations.

However, most of us have much smaller flocks and don't have the setup or frankly the need to produce perfectly optimized feeds. We have different concerns such as finding healthy supplemental foods, minimizing commercial feeds (for some of us) and becoming more self-sufficient.

I have some limited knowledge of human health/nutrition, but far less about chickens and have counted on your posts for much of my knowledge. I know in humans, it is sometimes the ratio of nutrients that is very important (ex: Omega-6:Omega-3 ratio), sometimes just getting sufficient quantities with virtually no practical upper limit (ex: Vitamin-C and Iodine) and sometimes you need to be in a specific range, with lower and upper limits (ex: Vitamin A). I'm sure the same types of rules apply to chicken nutrition.

After all that, my alternate point of view is I'm not terribly worried about a perfect balance (unless that imbalance is harmful), but sufficient/optimal quantities of nutrients. I think that 16% protein is minimal, but 18%+ is better for laying hens as I'm not aiming for short lives at the lowest cost, but instead longer and more healthful lives. You post a lot about Lysine and Methionine as key amino acids that are harder to get. I'll buy that. But is the ratio really the issue or just getting sufficient quantities of each? If you have excess of one and "sufficient" of the other, will it cause harm or just be a non-optimized mix?

 

[U_Stormcrow]

OK, so... I mentally skipped a lot of steps. Apologies for that.

I'm of the "meet the minimums" and if you have too much, so much the better, sort of camp. Mostly.

With typical feed ingredients, its almost impossible to have "too much" (as in, unhealthy amounts) of Methionine or Lysine. Of the two, I consider Met the most important. Met is analgous to the engine on a train, in that ALL proteins begin with Met. So if you want a long string protein, it starts with the engine, Met, grabbing another AA and starting the chain, which are like the cars that follow.

and just like a train, at some point the engine can decouple, leaving a bunch of railcars all connected together, and go make another chain - that's why you need more than twice as much Lys as Met - but without enough Met, the Lys is just wasted - goes out the butt as waste nitrogen, no benefit at all, because there is no engine available (Met) to start stringing it all together.

So that's what's going thru my head when I look at the AA ratios for duckweed, because I know how hard Met is to obtain in a typical poultry diet.

The next thing going thru my head is an assumption - an assumption that we are looking for the "standard" 100g ration, where 100g of ration feeds one production hen for one day - or very close to it - as opposed to a high nutritional density diet where a bird is fed less, or a low nutritional density diet where a bird is fed more weight of feed to meet their dietary minimums. Why? because it makes it easy. According to studies, a production hen needs,as adult, at least .3g of met per day (modern studies put that a bit higher). 0.3g of a 100g diet is also 0.3%. That allows the use of weight and % interchangeably, since stidues vary in which they report.

and I didn't forget that poster is looking to substitue duckweed for peas. Knowing the average Met and Lys levels of the typical dries winter pea (0.24 Met, 1.72 Lys) I can now make direct comparison between the two ingredients on the two AAs we are most focused on. And because the ration of Met to Lys in a winter pea is roughly 1:7, while the ratio in Duckweed is closer to 1:5, I know that as long as I provide enough Duckweed to meet the Lysine need as substitution of the peas, I'll also hit (exceed) the Met target -- that's a net benefit.

Then I started thinking about what I'd already read. All Duckweed is not the same. But the two most common types of duckweed here in the US, and popular for aquarium sals are Lemna Minor and Spirodela Polyrhiza. Of the two, one study said S Polyrhiza was more digestible. Another study (several, actually) had it slightly higher in total protein. Yet another had it as lower in fiber than L Minor (that's a good thing in chickens).

Now I know where I need to focus my time (and my math). Next post.

 

[TooCheep]

Thanks and excellent description of Methionine's role in protein formation.

 

[U_Stormcrow]

that brings me back to this study/paper here, source of the AA profile I found in a later study. I need this, because the numbers linked int he prior chart show relative protortions, but not units. I need to know how they are being measured.

First thing I found, as suspected, is that the crude protein levels being thrown around are on a DRY WEIGHT basis. Because of course they are. You don't find plants at 40% protein, unless some concentration has been done first.

In the case of duckweed, S Polyrhiza, the variety we are interested in, may well be 29% protein dry weight, but duckweed is 92-94% water. That means that if you skopped 100g of duckweed out of your pond, before drying (the plant, as opposed to sending it thru a salid spinner to remove moisture cling to the plant), the protein conten of the mass is just 0.29 * 0.06 - 0.08 = 1.76g to 2.32g. Yup, thats right 2% protein,+/-. To become a protein dense poultry superfood, you need to dry that 100g mass to about 7g in final weight - at low temp, since high temps can damage some AAs.

Now we know we need drying screens or beds as part of our setup.

Popping back into the math, we rreally need that AA profile to determien the units being used.

And here is our answer, "Comparison of essential amino acids in different species of duckweed compared to cereal grains, legumes, and FAOreference (g/100 g protein)."

That's % Protein. and here is the line for S Polyrhiza
Amino acid TrpThr Ile Leu Lys Met Phy Val His
S. polyrhiza N/A 3.45 3.75 6.85 4.3 0.83 4.2 4.4 2.15
Trp N/A
Thr 3.45
Ile 3.75
Leu 6.85
Lys 4.3
Met 0.83
Phy 4.2
Val 4.4
His 2.5

Pulling out just the two we want, and doing the math, 29% protien, comprised of 4.5% Lys is 1.3g/100g dry weight. That's a very good number, actually, but winter peas are better. 1.7 g/100g dry weight. How about Met? 29% * .83 = .24 g/100g dry weight. Winter pease are essentially identical.

That means to replace the Lys provided by winter peas in a given recipe, we need 1.7 / 1.4 (a bit over 1.2#) of dried S Polyrhiza for each pound of winter peas being substituted. And of course the daily ration has to be adjusted accordingly ( a miniscule amount for most recipes, as most comntain 10% peas or fewer). We'll end up with MORE Met in the substituted feed. HOWEVER, there's that thing, Tryp. Everybody ignores it - even me. Because in the typical soy/corn ration, if you have a minimum crude protein and hit your minimums on Met and Lys, its almost impossible to miss Thre and Tryp (Thre content in S Poly is about 10% higher than Winter peas anyways). WInter peas are right at the minimum recommend for Tryp (.2g /100g). It seems really strange that no Tryp level was measured in the S poly, though there was plenty in L Minor (the only Duckweed which listed a number for that AA). I suspect it simply wasn't measured - the chert was assembled from multiple studies - that's a subject of additional research for you.