How much food to gain 1 lb of fish

[scotteboy]

I read somewhere once that it takes 1.2 pounds of fish food to get 1 pound of fish. I cant find the site anymore, does anyone have this information handy? Specifically for rainbow-trout.

Cheers

[cedarswamp]

Under ideal conditions the feed conversion rate for rainbow trout is said to be 1:1.

Google "rainbow trout feed conversion rates"

[keith_r]

different fish species will have a different fcr.. different diets for the same species will result in different fcr's
largemouth bass (a member of the sunfish family) have an fcr near 10:1!
one of those "it all depends" questions, many studies on different fish have been published, google can be your friend.. i try to find more than one point of view/study/test

[scotteboy]

Perfect! Thanks guys

[cedarswamp]

My bad, make that "rainbow trout feed conversion ratio"

[urbanfarmer]

I have never seen a 1:1 ratio. Tilapia have been shown to get 1.2:1 under ideal conditions, but that is outdoors, specific strains, and they eat more than what they are fed by humans which is not calculated into the FCR.

What you feed them is important too. 32% cheap fish feed isn't going to give you the results of 45% feed, but the slower (more economical) growth could work out for you if it fits your needs, etc.

[keith_r]

and different fish do better with different foods..
32% is great for catfish, but not for trout/gamefish
ohio state did a study that showed a much higher fcr for tilapia (at least a couple different strains), and note in the study they had heaters fail - optimum growth may be a target, but i don't think to many "backyard" fish farmers are going to hit those numbers..
here's the report;
http://www.ncrac.org/NR/rdonlyres/B3FB5 ... eport1.pdf (http://www.ncrac.org/NR/rdonlyres/B3FB5382-8A97-40E8-9B32-8F8879C29B2C/0/tilapiareport1.pdf)

[urbanfarmer]

Nice keith, nice! :-D

[keith_r]

finally! a study you didn't rip apart.. hahahaha
i kid

[urbanfarmer]

"The research completed at Purdue, ISU, MSU, OSU, and SIUC is defining a tilapia diet and feeding strategies that will improved production in recirculating aquaculture systems."

North Central Regional Aquaculture Center, Purdue University, Illinois State University, Ohio State University, Michigan State University, Southern Illinois University-Carbondale... that's A LOT of peer review and education institutions doing what they do best! What's there to rip apart? That's good data!

It's not like you posted a research study done by AquaMax that concluded that AquaMax yielded the best growth. Or, research that the data shows something opposite of the conclusions or where the researcher even states huge flaws in his research and still draws the conclusion he wants regardless (as we have seen with the nitrate research here on Tilapia). Big difference!

[rfeiller]

you might contact the food mfg and ask them what what research studies they have with their foods and the performance of those foods.
are the fish basically carniverous, herbivorious, or omnivorious. the growth rate of bass was mentioned, if those bass are raised on beef heart the ratio is much better then using a general commercial fish food. beef heart is what i fed the bass that i played with and they had a fast growth rate. (in west texas at the time the local butchers threw away the hearts so they were free)

there is a vast difference in usuable nutrients in pet foods. how they derive at the advertised levels of proteen, fat, ash, etc. i saw a study years ago on channel cats. in this study the cat had a ratio of 1:1. the study was done at a large commercial hatchery. it was not sponsored by the pet food industry.

the film was a complete study on the channel cat in commercial fishing. film covered breeding, hormon injections to get the females to spawn, the set-up using 55 steel drums for individual spawning sites in a mud bottom pond, a paddle wheel device for circulating fresh water and air to the eggs, methalene blue as an antifungal for the eggs, through harvesting of the market size fish.

[cedarswamp]

"I have never seen a 1:1 ratio."

Neither have I.....but apparently the 4 different sources I referenced have. :D

[urbanfarmer]

:?:

[rfeiller]

Some of these operations invest a lot of money developing their programs. Something I would say most of us don't have access to the resuolts. Their formulas are not published.and certainly not closed systems.

[bcotton]

1:1 sounds a lot like perpetual motion... The fish excrete solid waste and they move/use energy. Lets not get into energy/nutrients spent if your fish try to reproduce. if fish are gaining 1lb for every 1lb of food then they are getting food/nutrients from somewhere else too.



brian

[rfeiller]

certainly not my fish, they are pigs! :lol:

[David - WI]

Much of the weight of a cell is water. Depending on things like the type, age, size, etc of the fish... only about 20% - 30% of the food is used for "growth" but up to 75% - 80% of the new growth is water; so you can (at least theoretically) have greater than 1lb of growth per pound of food.

[vermiman]

Much of the weight of a cell is water. Depending on things like the type, age, size, etc of the fish... only about 20% - 30% of the food is used for "growth" but up to 75% - 80% of the new growth is water; so you can (at least theoretically) have greater than 1lb of growth per pound of food.

Especially if you are feeding dry food.