Pond Boss Forums MANAGING AN EXISTING POND Feeding Fish Food Primer

This study in my opinion had an agenda. Soy Meal > Fish Meal. However useful information can usually be gleaned from any study.

Do you have a study that shows that a carnivorous species couldn't utilize starch?

Was the ingredient makeup of each diet reported?

Was the fish meal used whole fish meal? Is whole fish meal ever used in aquaculture?

I did some testing on piscivore's in this area. They consistently used up to 20% starch without passing any.

The 100% protein digestibility of soy meal can't be beat. However the 2% oil/fat needs to be limited because it has the wrong type of fats for fish.

At 92% - 93% digestibility whole fish meal is excellent. However without cutting the fat it could lead to health problems as noted.

Here are a few points from the PB presentation.

The immense variety of cultured finfish species hampers efforts to simplify production industry wide. Approximately 170 taxa are currently cultured, including carnivores, herbivores, planktivores, and omnivores, each posing its own set of nutritional demands .

Fish meal has proven to be an excellent dietary protein source for finfish, leading to its description as an ‘‘ideal protein.’’ The ideal protein concept is based on the premise that if the amino acid profile of the feed mimics the whole-body amino acid profile of the animal being fed, protein utilization and growth should be maximized

Lipids, fatty acids, and their derivatives play a role in virtually every physiological process that occurs and for this reason dietary lipid composition and content represent a massive sector of overall nutrition. Nowhere is this more true than in finfish nutrition where lipid can exceed protein in the body composition of finfish, a testament to the physiological and energetic importance of this nutrient class (Tocher2003). Aside from physiological importance, lipids are indispensable energy sources, especially for finfish, which are not well-adapted to carbohydrate utilization.

Dietary protein and energy must be kept in proper balance because a deficiency or excess of dietary energy can reduce growth rates. Fish fed diets deficient in energy will metabolize more expensive dietary protein to meet energy requirements. Excess dietary energy can decrease protein intake and suppress growth.

finfish do not require carbohydrates in their diet, … complex carbohydrates cannot be digested and utilized efficiently by most finfish species. A general dichotomy exists in the carbohydrate digestive ability of warmwater omnivores and herbivores versus the inability of coolwater and coldwater carnivores, which lack the appropriate function necessary for digestion of carbohydrates.

 For this reason, diets fed to these fish rarely contain more than 20% complex carbohydrate

Conversely, warmwater omnivores or herbivores (e.g., channel catfish, tilapia, common carp, and white sturgeon) adapt well to diets containing as much as 40% dietary carbohydrate .

Although vitamins and minerals are required in minute amounts compared with protein, lipid, and so forth, they are critically important, … Every micronutrient has a deficiency disease associated with it, the effects of which are sometimes irreversible or fatal. For a few vitamins and most minerals, excess can be equally detrimental, resulting in toxicity.


Abstract from 1 study

Reviews in Fisheries Science
Volume 11, Issue 4, 2003

Dietary Carbohydrate Utilization by

DOI:
10.1080/10641260390260884
David A. J. Stonea
pages 337-369
• Published online: 24 Jun 2010
Abstract
Aquaculture production is forecast to nearly double by the year 2010. Increased production can only be sustained with a concomitant increase in the production of aquafeeds. Presently, the protein source of choice in most aquafeeds is fish meal. Global fish meal production has remained relatively static over the past two decades, and there is no evidence to suggest that it will increase in the future. Therefore, alternative protein sources to fish meal will have to be found. Plant protein sources have been identified to have the greatest potential to replace fish meal protein. However, plant ingredients contain significant quantities of carbohydrates. The ability of fish to utilize dietary carbohydrates as energy sources to spare protein for growth varies, both among and within species. This review discusses the variability of carbohydrate utilization by fish commonly produced by aquaculture. Factors that affect carbohydrate utilization as an energy source to spare protein are carbohydrate origin, inclusion content, physical state, and molecular complexity. There appears to be potential for the use of supplemental enzymes to enhance carbohydrate utilization; however, care must be exercised with the use of such products as some of the breakdown products, particularly from nonstarch polysaccharides, such as galactose and xylose, are not tolerated by most fish if digested. The increased availability of these monomers may be detrimental to fish growth performance and health. Warmwater omnivorous fish have a greater potential to utilize dietary carbohydrate as an energy source to spare protein, than do coldwater and carnivorous species which utilize dietary carbohydrate poorly or not at all. This will place restrictions on the use of plant protein sources, which contain significant quantities of. carbohydrate in diets for coldwater and carnivorous fish. Consequently, the production costs of diets for warmwater omnivorous species will be cheaper than for coldwater and carnivorous species. This may have implications in the future for the selection of suitable species of fish to provide protein for human consumption.

Now we are getting somewhere.

Since this is a pond forum lets look at pond fish. Bass, Panfish, Catfish, Walleye and Tilapia come to mind. These are all warm water species. The only cold water species that I can think of is trout.

Bass, Panfish, and Walleye are carnivores.

Pond Catfish are omnivores.

Pond Tilapia are herbivores.

If we are talking about whole fish meal I agree.

What seems a standard 40% protein in carnivorous diets is adequate in my opinion. Its important to limit lipids (fat) if longevity is a goal. For a long time I agreed with you that carnivores couldn't use starch as an energy source. I used egg whites as a binder for this very reason. After some spirited discussion on the subject I had to test it. I fed a diet containing 20% starch certain it would fail. Using iodine as a reagent I tested the water and nothing. I was shocked at these findings. In fact warm water carnivorous species can use starch as energy.

Any of you that keep fish in tanks can test this. Take some water from the tank that you have been feeding a carnivorous fish food that contains starch, add iodine and see for yourself. If you see purple specs or the water turns purple starch is present.

Starch in excess of 25% - 30% will lead to health issues if any fat/lipids are contained in the food.

I agree for the pond owner it is a good hedge to feed a food with vitamins but have to as how do fish in ponds not getting vitamins in food survive?

Is an 20% inclusion rate of starch in the food the same as utilize dietary carbohydrates poorly?

IIRC Hydrolyzed chicken feathers are considered as "poultry by products" by some pellet manufacturers

Good fertilizer ... Would you want to eat a fish fed this stuff?

I have seen it in tropical fish food for far too long. At least you don't eat them.

There are others
YP are cool water fish and are carnivores as ars Esox
HSB are warm water/ cool water carnivores but can use carbs better
Then there are all the forage fish like GS ,Shads , chubsuckers etc

One point to keep in mind is that the vast majority of ponds that are fed are not like aquariums because the ponds are only engaged in supplemental feeding with the fish geting a large % of their diet from natural sources.

Can you lump YP & Esox in with trout?
HSB & SB are warm water fish that tolerate cooler water better than the others.
The forage fish in ponds are primarily warm water fish.

True so its even more crucial aquarium fish get a good diet. Carnivores get very little if any starch naturally. However that doesn't mean they can't use it. I have come to believe the ability to use starch is a survival mechanism.

IMHO Folks stocking forage up north to feed their WE, SMB, NP.... might disagree

I don't consider any of those fish warm water but that's how they are classified.

For sake of discussion and from above: ""Good fertilizer ... Would you want to eat a fish fed this stuff (Originally Posted By: Fish Food
.... If you ask me it beats the hell out of chicken heads and feet
...... and by BillD :IIRC Hydrolyzed chicken feathers are considered as "poultry by products" by some pellet manufacturers).

Correct me if I am wrong but isn't most all stuff (foods) injested and then digested by heterotrophs (consumers) first converted (digestion) to the basic "building blocks" of nutrients that are then reassembled by that heterotrophic consumer for growth and function? So regardless of the food stuff eaten isn't the final meat (protein-animal) basically the same for each species? Granted some food stuff and chemicals can be absorbed directly and thus flavors the meat but isn't the meat of each specie essentially the same chemical consistence (amino acids, etc). Animal fats commonly will have flavors from fat soluble chemcials, etc. I think even some chemicals flvors that are consumed are passed and while in the animal's system will cause flavors - odors. Garlic is probably one example. Off flavors in fish are another example that will be short term in fish exposed to those chemicals.

As far as protein it all depends on the amino acid profile.

For example shrimp protein is 70% digestible. Shrimp meal consisting of heads and shells protein is only 20% digestible. Shrimp meal is highly palatable but 80% of the protein is waste.

Protein digestibility percentages aren't available for most other parts meals.

As for fat fish do well on fat high in omega 3 and to a lesser degree omega 6.

Is this what you were looking for?

That is not really my point. But your explanation does create more questions.

I will use protein as an example. Original point was - Is not all injested then digested protein broken down into the basic amino acids and then those basic amino acids reassembled as new protein into the new organism; all controlled by that organism's physiological processes (ultimately DNA?)?

You new comment created this question - what makes a protein undigestable? Is it a coating on that protein or inability of the consumer's digestive fluids to separate the protein into the basic amino acids?

Hair is evidently not digestible by cats which is why they cough up hair balls??? However some organisms can apparently digest hair such as birds of prey and maybe bass or foxes who eat mice? Birds and some predators can digest bird feathers but fish can't normally digest feathers until the feathers are first processed???

I have found a mass of hair and bones hocked up by an owl. I don't think hair can be digested.

I don't know about feathers.

Yes I agree.

FWIW My understanding is the process of hydrolyzing (effectively pressure cooking) converts the feather protein from undigestible to digestible.

Lack of a complete or even near complete amino acid profile in the protein of the ingredient being ingested. It all gets broken down but all of the building blocks if you will are there to put it back together in a form the animal can use.

Eric may be have a better or more complete answer.

That makes sense. Still disgusting.