15 replies to this topic

[strat guy]

Anyone try feeding their fish various whole grains as supplements? I've got some oats sitting around and I wondered if they'd be a viable food source. I assume, like bird seed, they'd need to be soaked for a while first to avoid expansion in the fish's stomach, but aside from that, does anyone see any benefit in adding something like this to their diet?

[Matt DeLaVega]

No. Maybe long gutted fish. Otherwise not going to be efficient at processing them, and mostly just carbohydrates. I may be wrong, but it does not make sense to me.

[Betta132]

No food value whatsoever to a fish. Grains are used as fillers in pellets and flakes and the like, but that doesn't mean they're any good for your fish. 

[centrarchid]

Hold your horses.  Not all fish are predators and some of the herbivores may have the ability to handle carbohydrates well.  First OP, drop the use fish. 

 

 

 

Oats may be good for some gramnivorous catfishes from South America.  Fish like adult grass carp may also be able to handle  limited amounts of greens in the form of sprouted oats.

[don212]

strangely today i heard a news item about aquaculturists switching to a soy based feed

[centrarchid]

strangely today i heard a news item about aquaculturists switching to a soy based feed

 

The effort has being going on since the 1990's if not before.  Several problems remain with high among them being palatability and anti-nutritional factors.  It is very much a problem of interest to me with my domestication efforts.  The animals are being selected to perform on increasingly plant based diets which is almost certainly causing changes that will be measurable in the near term.  

 

I do not recommend the use of plant based or formulated diets on animals you are trying to keep in natural condition. 

[az9]

strangely today i heard a news item about aquaculturists switching to a soy based feed

I'm using a bluegill feed that has no fish meal. The fish are healthy and growing rapidly. Some are 8 inches and under a year old.

[Matt DeLaVega]

Big difference than whole grains. Whole grains are not highly digestible. Some of the processed feeds without fish meal are making better fish. Good growth and much better flavor least in my  opinion.

[gerald]

Do these fish feeds without fish-meal contain other animal byproducts, or are they totally plant-based?   I suppose it's possible over time that a predatory fish's intestinal bacteria community could gradually shift to plant-digesting bacteria, especially if the predators are housed with plant-eating fish.

[centrarchid]

Some are totally plant based although most have byproducts such as porcine meal or poultry meal.  The challenges grain based feed consumption presents to carnivorous fishes is not likely to fixed by exposure to probiotics released by plant consuming fishes.  The vegetative plants have components that vary greatly relative to grains.  Most of the problems are more to do with limitations of the fish GIT and physiology associated with carbohydrate intake.  I doubt the symbiots can transfer all those sugars and funky proteins into some the fish can subsequently process.

[Irate Mormon]

Doesn't Gordon's Formula have oats in it?  It's been a while - my memory fails me.

 

I wonder if anybody still uses it.

[Matt DeLaVega]

A rich guy I am friends with has a membership at a trout club. They have their own hatchery. A couple years back they switched to a vegetarian diet. The meat went from white and liver tasting to pink and salmon tasting. I do not know of the food name, but I know that it made an end product that was much better. I am 99% sure that Ohio has begun using something similar as their put and take stocked rainbows have become palatable in the last several years.

[centrarchid]

Changes you note are not directly related to protein source  or quality.  Taste is a function of dietary fatty acids and possibly fat soluble compounds coming from bacteria and microalgae in the environment.  The change in appearance of meat is a function of A-vitamers (forms of vitamin A) where many are responsible for red, pink, orange and yellow colors noted in flesh and skin.  As a general rule you do not see what is related above when switching to a grain-based feed formulation.  I see the same type of talk with poultry people where there is a consensus that "vegetarian" diets for animals are superior for all situations.  The diet switch needs to be better substantiated.  I could see where new diet is not as vegetarian as thought or something about diet was changed the hatchery manager does not have a handle on.

[Matt DeLaVega]

The hatchery manager was eager for us to try these new fish coming out of a rearing pond as they were fed a new vegetarian diet that was supposed to improve taste and color. I don't know the science of this, but this feed was apparently meant to do this.

[az9]

A rich guy I am friends with has a membership at a trout club. They have their own hatchery. A couple years back they switched to a vegetarian diet. The meat went from white and liver tasting to pink and salmon tasting. I do not know of the food name, but I know that it made an end product that was much better. I am 99% sure that Ohio has begun using something similar as their put and take stocked rainbows have become palatable in the last several years.

Is this the trout farm in Castalia that was purchased a few years ago from a private trout farmer? If so I met the manager as we another guy flew together to a coldwater RAS seminar.

[Matt DeLaVega]

No, this is the Zanesfield Rod and Gun club. Headwaters of the Mad river system. It is a neat place with huge fish, but it is not exactly realistic. They hatch brook, rainbow and browns.