Duckweed

[PotterWatch]

Has anyone used duckweed as a protein supplement for their meaties? We are thinking of growing a test batch using duckweed as a replacement (or increaser) for the soy in the food we get. We would initially use a finisher pellet that is around 17% protein and add dried or fresh duckweed to it to raise the protein to the level we want. I'm not sure how to figure out how much we would need to add, but I'm sure I will solve that problem before we get the chicks. If you have tried this, how did it work for you?

 

[Erica]

No, but I'm currently growing duckweed to try.

However the important thing isn't the protein level (overall) but the kinds of amino acids that make up that protein. I have a feeling duckweed is low in certain vital amino acids, though I'm not sure which ones (probably methionine).

The tricky part is to balance that with another protein supplement that has high methionine or whatever amino acids are missing.

Just from my experience growing the stuff, you need a huge water surface area to get the volumes required. Palatability seems good when fresh; I haven't tried it dried. It takes a lot of skimming to get the amounts needed, and when dried I have a feeling it would pack down to next to nothing.

Sorry I can't say more, it's very early days with duckweed... I've also got fish that eat it, so I find it hard to gather any amount worth giving to the chickens.

Best of luck, I'd be interested in reading how you go. I hope I don't sound too discouraging! (It's just that I find peas and sweet lupins easier.)

cheers
Erica

 

[Mrs. Mucket]

I'm interested in learning about duckweed too. I didn't realize it took so much water surface.

Erica, do you know if the edible blue sweet lupines grow wild in mountain climates? They look the same in pictures. We have tons of it growing all over and would love to feed it to chickens if it's edible.

 

[Erica]

Hi Mrs Mucket,
no, definitely don't feed wild lupins -- they're quite toxic. Sweet lupins have been bred to be low in the harmful compounds. They don't come that way in the wild, and can make birds very sick (as well as people).
Sorry about that!

cheers
Erica

 

[eatmorechicken]

Found this on a google scholar search

Nutritional value Fresh duckweed fronds contain 92 to 94 percent water. Fiber and ash content is higher and protein content lower in duckweed colonies with slow growth. The solid fraction of a wild colony of duckweed growing on nutrient-poor water typically ranges from 15 to 25 percent protein and from 15 to 30 percent fiber. Duckweed grown under ideal conditions and harvested regularly will have a fiber content of 5 to 15 percent and a protein content of 35 to 45 percent, depending on the species involved, as illustrated in figure 2. [see next footnote] Data were obtained from duckweed colonies growing on a wastewater treatment lagoon and from a duckweed culture enriched with fertilizer.

Duckweed protein has higher concentrations of the essential amino acids, lysine and methionine, than most plant proteins and more closely resembles animal protein in that respect. Figure 3 [see next footnote] compares the lysine and methionine concentrations of proteins from several sources with the FAO standard recommended for human nutrition.

[Footnote: Source: Mbagwu and Adeniji, 1988.]

[Footnote: Source: Mbagwu and Adeniji, 1988.]

Cultured duckweed also has high concentrations of trace minerals and pigments, particularly beta carotene and xanthophyll, that make duckweed meal an especially valuable supplement for poultry and other animal feeds. The total content of carotenoids in duckweed meal is 10 times higher than that in terrestrial plants; xanthophyll concentrations of over 1,000 parts per million (ppm) were documented in poultry feeding trials in Peru and are shown in figure 4. [see next footnote] This is economically important because of the relatively high cost of the pigment supplement in poultry feed.

Duckweed as poultry and other animal feed Feeding trials reported in the literature and carried out recently in Peru have demonstrated that duckweed can be substituted for soy and fish meals in prepared rations for several types of poultry: broilers, layers, and chicks. Cultured duckweed can be used as the protein component in poultry diets. Acceptable levels of duckweed meal in the diets of layers range up to 40 percent of total feed. Duckweed-fed layers produce more eggs of the same or higher quality as control birds fed the recommended formulated diets. Levels of up to 15 percent duckweed meal produce growth rates in broilers which are equal to those produced by control feeds. Diets for chicks, consisting of up to 15 percent duckweed meal, are suitable for birds under three weeks of age. Duckweed meal will almost certainly find as large a range of animal feed applications as soybean meal.

Lots of info for duckweed as chicken feed on the web, but I can't find any source that claims that it is a complete protein.​

 

[PotterWatch]

Great information! Thanks so much for posting it. This will be a long-term project of course, but if we can use it to lower our feed costs even by 5%, it will be a big savings for us.