The best way to add protein is to adjust what complete, balanced food you buy for them. Any supplement you offer your birds should be considered "treats", and not exceed 10% of their diet by weight, out of concern for unbalancing their diet.
Crickets, for instance, are a great source of protein - depending on information source you trust, they can be as high as 60% by weight (I suspect that figure is as powder, without shell/chitin). BUT they are also very high in fat, in fiber, and in calcium. Additionally, not all crickets offer essentially "complete" (meaning containing all amino acids) proteins. Some species of crickets are particularly low in tryptophan and threonine, as example.
Why does tryptophan matter? Another Tryptophan study. Another.
Not sure I trust all the numbers here, but at least it gives some indications of popular bugs and relative concentrations of protein, fat, and calcium -
Black Soldier Fly larvae (another popular chicken treat) are lower in protein, higher in fat, similarly high calcium, and tend to be more complete protein sources, due to their diet.
So, good as treats. So are mealworms. Not as a regular dietary supplement.
...and all that said, while I'm aware that one can improve one's flock by adjusting amino acid levels in the feed they get, that's a level of granularity that frankly isn't worth my time investment to research, understand, and start tinkering with - which is why I stick to the 10% rule for treats, unless there is clear indication of some dietary imbalance in my flock. Instead I et them free range a biodiverse poly-cultural pasture.
Crickets, for instance, are a great source of protein - depending on information source you trust, they can be as high as 60% by weight (I suspect that figure is as powder, without shell/chitin). BUT they are also very high in fat, in fiber, and in calcium. Additionally, not all crickets offer essentially "complete" (meaning containing all amino acids) proteins. Some species of crickets are particularly low in tryptophan and threonine, as example.
Why does tryptophan matter? Another Tryptophan study. Another.
Not sure I trust all the numbers here, but at least it gives some indications of popular bugs and relative concentrations of protein, fat, and calcium -
Black Soldier Fly larvae (another popular chicken treat) are lower in protein, higher in fat, similarly high calcium, and tend to be more complete protein sources, due to their diet.
So, good as treats. So are mealworms. Not as a regular dietary supplement.
...and all that said, while I'm aware that one can improve one's flock by adjusting amino acid levels in the feed they get, that's a level of granularity that frankly isn't worth my time investment to research, understand, and start tinkering with - which is why I stick to the 10% rule for treats, unless there is clear indication of some dietary imbalance in my flock. Instead I et them free range a biodiverse poly-cultural pasture.