Pond Boss Forums MANAGING AN EXISTING POND Feeding Home Made Fish Food

Excess protein fed to any fish will damage the kidneys to some degree. Yes excess protein is treated as waste. In adult fish its all about maintaining muscle and tissue. How can this vary from a carnivorous bass to an omnivorous catfish? The same size fish has the same mass of muscle and tissue to maintain.

From the Pond Boss Conv. Presentation – some of the text. There is a lot going on now wrt fish nutrition and the use of plant vs. animal protein sources.


Fish Nutrition
Applied Science for Small Waters



Bio-Energetics

• The study of the flow and transformation of energy within a particular system.
• Bioenergetics is the subject of a field of biochemistry that concerns energy flow and transformation through living systems.
• Growth, development and metabolism are some of the central phenomena in the study of biological organisms. The role of energy is fundamental to such biological processes. The ability to harness energy from a variety of metabolic pathways is a property of all living organisms. Life is dependent on energy transformations; living organisms survive because of exchange of energy within and without.
• Living organisms obtain energy from organic and inorganic materials. For example, lithotrophs can oxidize minerals . In photosynthesis, autotrophs can produce ATP using light energy. Heterotrophs must consume organic compounds. These are mostly carbohydrates, fats, and proteins. The amount of energy actually obtained by the organism is lower than the amount present in the food; there are losses in digestion, metabolism, and thermogenesis.



Basic Food Components – Nutrition

• 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.


FOOD HABITS OF WHITE AMUR, LARGEMOUTH BASS,BLUEGILL, AND
REDEAR SUNFISH RECEIVING SUPPLEMENTAL FEED
Ronald H. Kilgen
27th Southeast Association of Game and Fish Commissioners
Largemouth bass preferred fish and other animals (64%), but also ate some supplemental feed (32%). Bluegill stomachs contained more supplemental feed
(44%) than any other item, followed by insects and animal parts (28%), and plant
parts (17%). Redears seemed to prefer insect larvae (42%), but also ate plant
material (38%). White amur apparently did not compete with the sunfishes for
either natural or supplementary food items.


Mean fat percentage of Dorosoma spp. (24.2%) exceeded that of Lepomis spp. (15.2%) and fathead minnows (19.1%), but was less than that of mosquitofish (25.8%) and golden shiners (34.8%) . Bluegills had lower caloric contents than gizzard and threadfin shad ; preliminary data collected for the present study also showed Lepomis spp. To the lower in caloric content than the clupeids.



Although carnivorous fish species generally have a limited ability to use carbohydrates for energy, hybrid striped bass are relatively adept at it. Digestibility coefficients for the carbohydrates were generally high (83.3 to100 percent), indicating that both simple carbohydrates and complex carbohydrates were digested efficiently by these hybrids




Key Science Points

• Because fish growth often is limited by food availability, supplemental feeding is a logical tool to improve the condition of fish in small impoundments as the energy cost for bluegill to feed on pellets is small relative to the high caloric intake, which can be 4-5 times greater than those fed natural foods (Schalles and Wissing 1976).
• Substantial increases in the standing stock of bluegill in ponds that receive pellet feed have been recorded (Schmittou 1969) and, in lakes, pellet feeding has been found to increase the number of large bluegills (Nail and Powell 1975).
• These results indicate that total fish production and production of bluegill were each increased approximately 75 to 80% by supplemental feeding in 19 months after stocking (Schmittou 1967)

• Previous studies demonstrated that feed in excess of 10 pounds per acre per day in bluegill ponds was not utilized. Some accumulated and decomposed, thus depleting the supply of dissolved oxygen which resulted in fish kills (Schmittou 1967) .
• the rate of growth of sunfish can be increased by short-circuiting the food cycle, thereby producing harvestable size sunfish in a shorter period of time than would occur under natural conditions (Carnes 1966).
• The pellet size should be approximately 20-30% of the size of the fish species mouth gape. Feeding too small a pellet results in inefficient feeding because more energy is used in finding and eating more pellets. Conversely, pellets that are too large will depress feeding and, in the extreme, cause choking. Select the largest sized feed the fish will actively eat.
• Addition of supplemental pelleted feed did not contribute to the rate of growth of young shad, but did increase the growth and spawning frequency of adults.


Also do a search for posts by Griffin (Mark Griffin pHd fish nutritionist) here are a couple for reference.

Well, today I see that Yahoo has a story on the importance of omega 3 fatty acids for us humans. For most of us, the source is fish - salmon, tuna, sardines, etc. I have not seen the data - but, for winter survival, the idea is that fish oil is a fluid. This enhance membrane fluidity. This is often cited as a reason for the role of PUFAs with brain function/development. When the water gets cold, the fish get cold. Therefore, it stands to reason that these fats benefit the animals in cold conditions. If the overall fatty acid profile has too much saturated fat, their fat reserves will solidify in cold water - like tallow in cold water. These PUFAs are important in many other aspects besides the physical properties....

Predatory fish get these fats from the smaller fish they consume. They do not synthesize the long chain PUFAs. The source is from algae and these fats are passed on to algae-eating zooplankton and fish and move up the food chain. Menhaden are excellent sources of the omega 3 PUFAs, because they are fatty fish and about 25% of their fatty acids are the long chain PUFAs. So, in a prepared diet, you need either a significant amount of certain marine algaes, or fish oil or meal (approximately 10% of fish meal is fish oil - as a side note... this is because fish meal is mechanically expressed, so it does not get all the fat out. In solvent-extracted meals - such as soybean meal - there is vurtually no fat left).

Feather meal as a fish food protein source. There are two primary factors of protein quality for monogastrics (fish for this discussion) - 1) Amino Acid profile and 2) Amino Acid availability. The amino acid profile of feather looks pretty good if you look at the Total Sulfur Amino Acid content. It has a high content of cystine - a sulfur amino acid (SAA). SAAs can be limiting in monogastric diets and tend to be expensive to formulate into diets (they are relatively low in many inexpensive plant proteins). Unfortunately, the reason it is so high is because feather is a structural protein. The di-sulfide bonds between two cysteines make the protein very tough. This is what gives the keratins their structural rigidity - like our hair and fingernails. Unfortunately, this serves to make them very hard to digest. Therefore, as a rule, the availability is not so good. To increase the availability, feather meal is often hydrolyzed, this is an attempot to break down the disulfide bonds to increase availability. Shoe leather analyzes at 85% crude protein, but it is not digestible.

A word on protein sources.... Most protein sources are available in different qualities. This is particularly true for the expensive animal proteins - fish meal, poultry meals, blood meals, etc. Quality and freshness of the raw materials and the processing are factors that result in this variability. As examples:
A) Quality of Raw Materials: Meat meals are often priced on protein content - simply put, it is the ratio of bone (ash) to meat (protein). Bones (minerals, ash) are not as valuable as protein.
B) Freshness of Raw Materials: The US commercial fishing fleet for menhaden now has all refrigerated vessel storage.... the season is in over the summer, primarily in the Gulf of Mexico. Obviously, if it is not refrigerated....
c) Processing: Blood has a good amino acid profile. If it is drum-dried (essentially scorched on a extremely hot steel drum) it has poor availability and is a fairly poor ingredient. If it has been spray dried under low heat - it is an excellent ingredient.

High quality fish meal is the gold standard - it has the best Amino acid profile for fish (fish protein to grow fish protein)and is highly digestible. Further, it tastes great to fish (fish meal based diets are much more palatable to carnivorous fish) and it contains about 10% fish oil (high in omega 3 polyunsaturated fatty acids). Many other proteins can be used as long as they are formulated properly into an overall dietary amino acid profile.

Holler if you have questions. MEG

Just depends on what warm water fish you are feeding and what results you desire. For instance, when grown at 80 F, fingerling Hybrid Striped Bass growth varied significantly, depending on both type and content of dietary protein and content of fat. Catfish formulations are plant based, while good trout/salmon formulations are animal based (preferably fish based). Strictly carnivorous fish do not do as well on plant-protein based diets. Below, diets are described in terms of Protein/fat, so a 40/10 is 40% protein and 10% fat (the OLD reliable trout diet).

36/8 (plant based)... 280% Weight Gain X
42/4 (plant based)....347% " 1.24X
35/10 (fish based)....432% " 1.54X
44/8 (fish based)....487% " 1.74X
55/15 (fish based)....650% " 2.32X**

It is important to note that all of these diets were high quality, they were just designed for different purposes and vary greatly in cost. For instance the 36/8 is designed for channel catfish fingerlings and the 55/15 is designed for Atlantic Salmon fingerlings. The 55/15 may cost 4 times as much as the plant based 36, so the economics are certainly arguable... just depends.

**Additionally, the ultra high growth on the 55/15 should be taken with a grain of salt as it resulted in obese fish (HSB very efficiently lay down dietary fat in their abdominal cavity), indeed the whole-body fat of HSB fed the 55/15 was 62% greater than that of the fish fed the 42/4.

Lets revisit this topic on LMB this fall as Bob Lusk is working on a trial this summer that should give us some more to discuss. Mark

Very good read Mark!

I take exception to:

For many years I bound my aquarium food using egg whites. This gave me the highly sought after high ground concerning the use of carbohydrates as a binder. I finally did some testing on tropical carnivores and found that they could use at least 15% energy derived from carbohydrates. I can't speak to cold water carnivores but as for warm water carnivores its simply not true.

Looking forward to hearing what Mr. Lusk's trial reveals.