Backyard Aquaponics
A place to discuss aquaponics

In my quest to find and make my own fish food i have come across a protein source that is quite high. Certain sprouts are close to 30% protein but when dreid they can reach over 50%. Just by looking at the other nutrient levels in sprouts it seems like all a fish, or human for that mater would need would is in there. I will combine the dried sprout powder with soldier fly larvae, eggs, ground up fish meal from my minnow traps, and soy flour. I know the tilapia will eat the dried sprouts if i put them in the tank. Just wondering if there can be too much protein/nutrients. When i practiced as a nurse if someone had kidney failure we fed them a very low protein diet so their kidneys could handle it. Could I possibly send my fish into kidney failure??? Also looking for some more feedback concerning the whole "sprouts for fish food" idea.

thanks
MM

There was a recipe on here somewhere for home made fish feed, it was something along the lines of 1 part fresh sprouted wheat, 1 part coarsely ground wheat, a couple of eggs, shell and all, then some sea salt for minerals..

I'm pretty sure that's all that was in it, it was posted here somewhere... Dunno about the high protein effects on fish though...

Quite possibly, I know that Silver Perch (an omnivorous fish) are known to suffer liver dysfunction when fed on high protein diets.

I read a study not long ago that compared grow rates in tilapia on different protein percentages... The results, as I recall, were that fingerlings grow best at 36% protein and then once a couple inches long they should be on 32% protein.

Remember, they need a bunch of other stuff besides protein... If a human eats nothing but protein he will lose excess fat weight, then quickly lose energy and strength levels as well show signs of lowered immune system... We NEED carbs and fat as well as a ton of micro things...

CB

Most commercial fish feeds and other animal feeds are studied to try and come up with the cheapest feed that will still give the max growth rates. Generally the protein % is the minimal amount to give the max growth and the commercial feeds also have the vitamin and mineral ad-mixtures to make sure there won't be any deficiencies that would cause a loss of productivity. Saddly most animal feeds here in the USA are most made of corn and soy and have only the minimal other ingredients to keep production up. Corn and Soy make for poor Omega 3 and omega 6 ratios, hence farmed fish are often not as healthy to eat as their wild caught counterparts (as far as the omega 3 and omega 6 ratios go at least.)

Anyway, about the protein levels. I suppose you can get too high of protein levels but I think to a large extent, it may have more to do with the balance of things. Some fish need a certain amount of fat as well and carbs and if the balance among the different elements is off then problems arise. This is why worms and BSF larva are not a good complete source of nutrition for catfish or tilapia because there is too much fat that can mess with liver function of the fish.

Now I've actually been told that tilapia fry and small fingerlings actually need far higher amounts of protein for fast growth and you don't want to drop down to the 32% or 36% till they are fairly well grown (like probably 6 inches.) But that is probably for max growth rates and I know they will still grow on 36%. Research I've done on tilapia actually says 36% is optimum for them. It is the channel catfish that optimum minimal amount of protein is 32%. Catfish still do fine on the 36% with no negative impact.

It should also be noted that the higher the protein level beyond what the fish actually need is going to put more burden on the bio-filtration since excess protein is going to add more ammonia and require more filtration than would other wise be needed.

So, one should do a bit of research into the particular fish being grown and what optimum levels of protein, Carb, and fat would be for them and then try to create a feed that has levels and ratios similar to what the research says is good. Granted this might be difficult without a lab but one can at least try and estimate.