Discus questions

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Thanks for the info guys! Heated debate going on here.. I'm currently trying feeding them NLS 1mm Discus pellets and NLS Thera A+ pellets, mix with frozen blood worms. I've done alot of reading about discus care, and am aware of the daily water change and feeding, but it doesn't hurt to check back with some of the discus expert we have on here :) I've remove the driftwood as suggested. I do have a larger tank for them already set up and running.
 
Skip the BW. They offer little if any nutritional value. Protein being roughly less than 5% and thats the highest amount macro-nutrient they contain. They contain mostly water. You're better off sticking to pellets. Blackworms would be a better alternative to BW.
 
OP I agree if you get your Discus on a quality pellet like NLS you'll be quantum leapes ahead of 80% of the others. Advances in fish food nutrition has come a long way since the early days of Beef Heart, home made concoctions and all the snake oil mixes you see out there.

:duh: The crap that some (not all) of these Discus afficianados throw in there tanks boggles the imagination and is about 20 years behind the times. If you were a mass producer of Discus and needed size fast then yes go for it. These are not going to be your fish, bulk'em up and ship'em out. If you want to keep beautiful fish healthy and extend thier life as long as possibile feed them a complete diet, NLS will give you everything your fish need. I've used it for years on all my fish, the RD in my avatar has eaten nothing but NLS it's entire life it's 13+ inches of bad intentions and flawless.

Good luck with your Discus.
 
Thanks guys. I got 2 more today so that makes 7. I noticed after I got the 5th one that they stop huddling in the corner and actually parade around the tank. I usually clean off anything pellets they don't eat after 15 mins but today when I check, some pellets were missing so I hope that some actually are eating! It's so hard to starve them but I have to get them to eat pellets when young. How long did it take for your discuses to a accept pellets guys?


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Well hopefully you aren't starving juvie discus that are only 1-1.5".

A good way to convert picky fish to pellets, including discus, is to pre-soak the pellets in thawed out frozen blood worms for approx 10 minutes. Doing so will add extra flavor & odor to the pellets, as well as soften them up, and this will make them more palatable to a fish. Do this first thing in the AM at their first feeding of the day when the fish are at their hungriest. You should also be prepared to feed other foods, such as flake foods if they don't convert to the pellets straight away. NLS makes a quality flake food, as do others, but whatever you do at this size do not starve them in an attempt to convert them to pellets. You might want to find out what they were being fed at your LFS, and include that in their diet for now as well. Pellet training can always come at a later date when these fish are in proper condition & have some size to them.
 
Thanks for the the info rd! They are eating the pellets, but not as much as I want them to but it's progress! O will try the blood worm trick when I get home later


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a lot of you guys seem to like the NLS discus pellets, anyone here use hikari bio-gold? or is NLS the superior food? i'm just wondering because i want to transition my discus to pellet food for better nutrition and ease of feeding. thanks guys
 
Certainly discus can be finicky feeders, which is why one cannot always feed live and/or frozen and expect their fish to accept a dense feed such as NLS. In many cases it becomes an all or nothing approach.

The fish that I posted photos of on page one were all started off on beefheart, as all Stendker discus are, as were every other group of juvenile discus that breeder imported, and all of them were converted to NLS pellets with little issue. Having said that, he fed no bloodworms, no beefheart, no live, or frozen of any kind. This is someone who had raised & bred discus for 20+ yrs, all on beefheart mixes, and decided that this time around he was going to take a different approach. Eventually all of his adult groups that paired off also bred like rabbits, producing tons of fry, and all on a diet of NLS. His fish room consists of 3,000+ gallons worth of discus tanks, so it's large enough to supply some good overall data as far as feed, growth, breeding, etc. One of the first things that he noticed is that when feeding a clean food such as pellets, there was no longer a need for daily water changes.



Even though many people still consider discus to be carnivorous, we now know that in the wild, discus are NOT a carnivorous species that require massive amounts of protein or fat for proper growth. Certainly, young juvenile discus require protein in the range of 45-50%, but that could be said about pretty much every juvenile species of cichlid kept in captivity, including those classified as herbivorous. But as a cichlid begins to mature, their nutrient requirements in captivity change due to metabolic changes within the fish, and as this metabolic change takes place, so does their high demand for both protein & lipids.

Here's a link to a recent scientific paper that every discus owner/breeder should read.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400008






Of course if one is in the business of growing discus out for resale, then the main goal (at least in many cases) is to get the fish as large as humanly possible, in as short of time frame as humanly possible. I think that a lot of discus would have much longer lifespans if people weren't in such a rush to have 6-7" inch fish. A poll taken a few yrs back on simplydiscus had the average lifespan of a tank raised discus at 4 yrs, which IMO is pretty pathetic.


Several years ago Chong et al ran a 3 month feed trial on juvenile discus (fish approx. 4.5 grams in weight) and concluded that a diet consisting of 45-50% protein, and 8% fat was ideal for optimum growth for juveniles of this species. I have no argument with those stats, and again the same could be said for thousands of other ornamental species of fish, but somehow this data has been used by certain segments of discus keepers to support their use of a high protein diet for semi-adults & adults. Where's the science to support that?


According to Heiko Bleher, his data matches those of the study linked to above.






A couple of things to keep in mind. Firstly the protein % found on all NLS labels are minimum values listed, not actual. Secondly I have seen adult discus eat the Grow formula pellets, so juveniles will certainly have no issue with smaller pellets, any more than any other species of cichlid does when offered smaller sized pellet food. With the smaller sizes of a discus mouth feeding small pellets is certainly not an issue.


As far as protein goes, one has to also remember that not all protein is created equally.

The protein percent on a label doesn't tell you anything about the quality of the protein, only the quantity of nitrogen that's been determined by someone wearing a white lab coat.

The value of protein is directly related to the amino acid content. A label % doesn't tell you how that protein was processed, or if it's even in a form that your fish can properly digest & utilize. As an example, feather meal is quite high in protein, but can be generally poor in overall digestibility. A fish food label could state 45% protein, but if only 60% of that protein is in a form that's available to the fish, then suddenly that figure on the label becomes somewhat meaningless to the average consumer, and their fish.

This is why I shake my head when I see hobbyists on various forums discussing protein % on various labels, as though Food A with 45% protein is somehow superior to Food B that has 35% protein on the label. The only protein that truly counts, is the digestible protein (DP) as in the amount of protein that can be fully assimilated by your fish.


This is not to say that there aren't other ways to get good growth & supply good overall health to a discus, but to state that one can't feed pellets alone & get the same results, is clearly not accurate.
I believe that people should also read this article on discus digestion. http://forum.discusnews.com/viewtopic.php?t=6707 It breaks down what a discus can digest. Yes discus in the wold are found with mostly plant matter...but a discus utilizes the protein in the plants.
The findings were “cross checked” in lay terms. That is, the results obtained by the above method were compared to results of molecular weight “markers” for proteases. What was found is that discus stomach and intestine contain two groups of digestive enzymes with the ones in the stomach working best at a pH of 2.0 while the group in the intestines worked best at a surprising pH range of 7.5 - 9.0 and at a second range of 11.5 – 12.5. The pH ranges further confirmed the findings of the intestines containing the proteases Trypsin and Chymotrypsin and Metalloproteases while the low pH of 2.0 inhibited the functioning ( if present ) of these proteases in the stomach. The discus stomach pH confirmed the finding of “pepsin-like proteases” in the stomach, which require a pH range of 2.0 – 3.0 to fully process proteins consumed by the fish. The high level of Chymotrypsin ( .61 average ) and Trypsin ( .79 ) matches or exceeds the levels in the intestines of other “carnivorous” and “omnivorous” fish. Also matching the profile of “carnivorous” fish is the low presence ( .09 - .03) of these proteases in the stomach of discus. Further matching a carnivorous fish’s “enzyme profile” is the actual “activity” of Trypsin above the level ( nearly double ) of Chymotrypsin which would be reversed for a fish able to sustain itself on plant material / vegetable material. In total, 8 specific proteases were identified, located and “activity” noted.
Further into the study of what discus can digest and gain nutrients from and what they are fed was a study on the digestibility of several common feed protein sources and the uptake of the protein from those sources. In lay terms the study used two separate testing methods as a “self check” type of system. Furthermore, these testing methods were applied “in vivo” and “in vitro” ( in a live feed study and in a cultured media study [ four separate culture methods ] ). Both methodologies gave the same results on digestibility of the protein source and the same results on the digestibility of the protein from each source.

Six sources were tested: casein, fish meal, poultry offal meal, beef heart, soybean meal and wheat meal. All six ingredients were made into a “feed” ( food mix to you and I ) with a seventh feed used as “reference feed” for comparison purposes. This seventh mix ( reference diet ) was the result of a prior study on protein requirements of discus for best growth.4 Results of this study verified that plant meals are not well digested by discus but that the proteins from plant meals is digested well, suggesting that if processed so that the “raw protein” from plant matter can be produced for adding to feed mixes, discus could then make use of plant proteins. Over all, the “rankings” of digestibility of dried meals in the study and the processing / uptake of the proteins from these meals were Casein, Fish meal, Beef heart, Soybean meal and Poultry offal meal and Wheat meal equally lowest.

This study also explained that high carbohydrate, ash and fiber content blocks protein uptake in discus which further explains why discus grow better on a carnivorous diet rather than the standard omnivorous fish diet incorporating vegetable matter. Also found was that discus over all can not digest dry matter as well as they can digest the proteins of those dry food sources, suggesting that discus fit the “profile” of carnivorous fish more so than the “profile” of omnivorous fish. The study concluded that for commercial farming of discus, beef heart might be the choice source for protein to base a dry feed ( food mix ) as Casein ( milk protein )5 is even more costly than fish meal, and that Soybean meal would have to be cooked and then dried into a powder which would also make it very costly.
This discus specific study was undertaken to ascertain the best protein content percentage for discus translated by the fish into growth and weight gain. Five levels of protein content were used, 35, 40, 45, 50 and 55 percent protein with protein derived from fish meal, casein and gelatin. Best growth over the 12 weeks of the feed trial was obtained at a maximum of 50.1 percent protein while best conversion of protein into growth was at 45 percent with the “overall best” growth and protein “conversion” occurring at a mathematically determined 44.9 percent. “Overall best” being the most growth / weight gain over 12 weeks with the least feed mix needing to be fed to the discus. Of the feeds fed, the 45 percent protein food gave the most growth with least amount fed daily.

The dietary protein levels needed by discus exceeded the protein levels needed by other studied fish except true “carnivorous” fish. These fish being the Brown trout and Snakehead. The discus requirements also exceeded other studied ornamental fish’s protein requirements. Crude fat ( lipid ), Ash and Fiber were at 8.3 percent, 5.0 percent and 1.6 percent respectively, on average for each of the feed mixtures. Increasing the Lipids or Fiber reduced the growth of the discus, while increasing the protein content above 50 percent also retarded discus growth. The conclusion was that increased protein reduced growth through the needed expenditure of more energy to expel the extra amino acids not taken up by the proteases of discus. The reduced growth from increased Lipids was found to be from the “binding” affect of fatty acids upon peptides and hydrolyzed proteins ( binding of “partially digested” protein ). Increased levels of Ash or Fiber were found to increase the speed of “exit” of the feeds, thus decreasing “exposure” of the protein sources to the proteases ( digestive enzymes ) of the discus fish.
Tying all these into one picture of discus dietary needs and digestive capabilities leaves one with a view not popular in the hobby, that discus are not vegetarians, do not and can not digest vegetable material but are very much able to digest proteins from both “meat” and “plants”. The concept of “adding more protein” only proves out the findings of these controlled studies upon discus, that when adding material the discus fish can not actually digest, one must supply increased protein to make up for the decreased uptake of the protein in the food.

For those who “want to know”, yes, the feed trials included “poop collection and analysis” along with chemical study of the tank water before water changes were made. This is how vegetable matter and fiber were found to have the noted affects upon discus and how protein and amino acid level “in the fish” versus “in the water” were also verified in the “in vivo” feed trials.
 
I believe that I have read every study/paper that Chong et al have produced over the years, and they all come to the same conclusion - juvenile discus, like most juvenile cichlids, require higher protein levels derived from animal sources (such as fish) and not large amounts of terrestrial based grains, which they will not digest or assimilate as efficiently.

Exactly what I have stated for years.



From Fred's article.
This study also explained that high carbohydrate, ash and fiber content blocks protein uptake in discus which further explains why discus grow better on a carnivorous diet rather than the standard omnivorous fish diet incorporating vegetable matter.

LOL, no kidding! But keep in mind that the fish in these various studies are immature juveniles, not adults. No one is suggesting that any juvenile cichlid should be fed high levels of carbohydrate.

Here's a link to one of the actual studies by Chong et al regarding the enzymes juvenile discus create for digestion.

http://idisk.mac.com/chowyang/Public/038.pdf

Again, the discus in that paper are only 10 weeks old.

None of that means that a certain amount of the nutrients found in plant material, especially those derived from aquatic plant matter, cannot be utilized by a juvenile discus. This simply means that one should not be utilizing the "protein" from plant material in feed, and expecting optimum growth results, especially when large inclusion rates are used. See the difference?

There are numerous bioactive compounds found in aquatic plant matter, such as spirulina, algae meal, etc, that are not present in fish meal, beef heart, etc, and these ingredients have been proven to have a probiotic effect on fish. Some of these compounds have been shown to have biological effects in fish such as growth promotion, immunostimulation, anti-stress, anti-bacterial, anti-fungal, anti-virals, and appetite stimulators. They aren't added for "growth" purposes.

These studies add little to what anyone who has raised any juvenile cichlid already knew decades ago - if you cheap out on the source of protein, and incorporate large inclusion rates of carbohydrate, especially those that are terrestrial based and are known to contain anti-nutrional matter - you will get less than optimum growth rates in your juvenile fish.

That does not equate to a "discus" being a carnivore at later life stages, anymore than it does with any other species of cichlid. And that's where Fred & many others have dropped the ball when it comes to discussing the diet of discus.


There are those that have stated that protein derived from "soy" cannot be digested by a discus, and that soy isolate will simply pass through a discus unused. LOL

Really?

Next time someone starts spouting nutritional factoids on a discus forum you might want to ask for a reference.


http://journals2.scholarsportal.inf...i0011/913_aosmidftafrs&form=pdf&file=file.pdf

Assessment of soybean meal in diets for discus (Symphysodon aequifasciata HECKEL) farming through a fishmeal replacement study
Aquaculture Research (September 2003), 34 (11), pg. 913-922


Abstract

A 12-week feeding trial was carried out with discus (Symphysodon aequifasciata HECKEL), a valuable ornamental species produced in South East Asia, to determine the suitability of using soybean meal as a partial fishmeal substitution in the diet. Juvenile discus (4.3–4.8 g) was fed eight experimental diets with graded levels of soybean meal replacing fish meal (0%, 10%, 20%, 25%, 30%, 35%, 40%, 50%). Growth performance (relative growth rate, specific growth rate) decreased and feed utilization (feed conversion ratio, protein efficiency ratio) was worsened at 30% replacement and higher. Amino-acid analysis indicated methionine and lysine deficiencies at dietary high soybean replacement levels, although the essential amino-acid requirements for this species are unknown. The level of soybean in diets negatively affected both dry matter and protein digestibility. This present trial showed the need for further studies involving amino-acid supplementation, different soy products and palatability enhancement to improve utilization of diets containing soybean meal to allow higher than the maximum 30% replacement level suggested here.



Of course a discus can assimilate & utilize the protein from soy, just as most other species of fish can, including trout & salmon, but there's a breaking point as to how much different species can effeciently utilize, before growth begins to suffer. In the study above the breaking point with soy replacing fish meal, and fed to a juvenile discus, was found to be 30%.
 
BTW - just so there's no further misunderstandings with regards to the various studies performed by Dr. Chong et al, all of these studies were developed with one thing in mind - a more efficient way for commercial producers of discus in SE Asia to raise discus to marketable sizes. In other words, a less costly way to raise these fish, the same goal that all commercial hatcheries have, including salmon, trout, catfish, etc.

Another study that Chong was involved in.

Inhibition of protease activities in discus Symphysodon
spp. by three plant meals


http://www.springerlink.com/content/p703851105553221/

.... where in the abstract they state:
Results from this study showed the potential of both soybean meal and wheat meal as ingredients for practical diet for discus, while demonstrating the need for further improvement in processing method for winged bean meal.

These studies aren't comparing raw ingredients such as wheat flour that are used at low inclusion rates as a binding agent, nor are they comparing soy ingredients such as soy isolate, or soy concentrate, that do not contain any of the anti-nutritional matter found in soybean meal. The reason for that is simple, isolates & concentrates cost a LOT more than soybean meal. A LOT more. These studies are looking for ways to reduce fish meal, and reduce overall production costs, NOT ways to increase them.

From the paper above..........

Introduction

Farming of tropical fish for the aquarium trade is an important souce of income for
several Asian countries (Andrews 1990). Ng and Tan (1997) estimated that South
East Asian countries produced ornamental fishes valued at USD 80–150 million
annually. Discus, Symphysodon spp., originally consisting of 2 species and several
subspecies, is widely cultured in South East Asian countries for the ornamental
trade (Chapman et al. 1997; Koh et al. 1999).

Discus farmers currently rely on freshly–prepared moist feed consisting of various
feedstuffs such as beef-heart, cockles, shrimps and blended plant ingredients.
These feeds may result in good growth but have a detrimental effect on water quality
as they disintegrate easily during feeding causing high-nutrient content effluents.
In addition, nutrient levels of these feeds could be unnecessarily above or below
the optimum level required by the fish, hence the need to develop nutritionally
optimized cost-effective dry diets for farming activities. However, until now, knowledge
of nutritional requirements was limited to a protein requirement that had been
estimated in an earlier study (Chong et al. 2000).

Fish meal is traditionally used as a protein-source in aquaculture due to its high
protein content, balanced essential amino acid profile and good digestibility. The
global shortage in fish meal production together with the increasing demand from
poultry and livestock feed industry have caused an increase in fish meal prices. The
need for more readily available and cheaper dietary protein sources has led to
evaluation studies on the use of various plant proteins as fish meal replacers in
aquaculture diets.

Bingo! An increase in fish meal costs, especially higher quality fish meal derived from whole fish, such as herring meal, has caused commercial producers to seek less costly alternatives for protein. This same mantra is constant in every study, where they discuss intensive culture of discus.

From a previous paper ......

Discus Symphysodon aequifasciata. is an important ornamental fish cultured in Asia with a high and consistent demand for export. Discus farming in recent years has shifted from cultivation of wild strains to various types of cultivated varieties generated through strain selection and interbreeding programmes Koh et al., 1999.. Most discus farmers rely on freshly prepared wet feed based on several ingredients such as beef heart, shrimp and cockles as protein sources. These feeds are inconsistent in terms of nutrient content and disintegrate easily in water. The development of a dry, economical and highly digestible formulated feed with adequate nutrient content is therefore desirable for intensive culture of this fish.


Again, from that same paper linked to above ......

Conclusions

This present study showed that the methods applied were able to detect the degrading
action of anti-protease inhibitors in different test plant meals more rapidly than
the usual trials which involve feeding the animals diets with different inclusion levels
of ingredients and monitoring subsequent growth and digestibility. Soybean
meal and wheat meal remain potential choices as practical ingredients for discus
diet formulation when inclusion levels are kept low since significant inhibition was
only evident at high concentrations. As for winged bean, an improved processing
method compared to the one used in this study is needed to further remove the
anti-proteases inhibitors present.


Soybean meal and wheat meal remain potential choices as practical ingredients for discus diet formulation when inclusion levels are kept low since significant inhibition was
only evident at high concentrations.



Does this mean "soy" in any form is the best way to provide protein to a discus, absolutely not, but at the same time it does not mean that adding a low inclusion rate of soy, or other plant matter is going to have a negative effect on the growth or long term health of a discus. It does also not equate to feedstuffs such as beef heart being more ideal for the long term health of a discus, no matter what people like Fred Goodall would have everyone believing.

Ironically enough, the 10 week old discus used in their enzyme study were being raised on a commercial food that contains numerous ingredients derived from terrestrial based plant matter. Remove the fish meal & it looks more like a recipe for pancakes, than it does a fish food. Yet this has been a popular food for discus hobbyists for decades. Go figure?
:screwy:

Juvenile discus S. aequifasciata. were obtained from stock originating from a breeding programme initiated at the Aquaculture Research Complex, Universiti Sains Malaysia. Ten-week-old fish with a mean initial weight of 5.2"0.8 g were selected for enzyme extraction. The fish were previously maintained on Artemia nauplii for the first 3 weeks after hatching followed by dry pellets Tetrabits. at a rate of 5% body weight per day.

Ingredients: Fish Meal, Dehulled Soybean Meal, Wheat Germ Meal, Wheat Flour, Corn Gluten, Feeding Oat Meal, Potato Protein, Shrimp Meal, Dried Yeast, Wheat Gluten, Monobasic Calcium Phosphate, L-Lysine Mono-Hydrochloride, Lecithin, Algae Meal, Soybean Oil, Ascorbic Acid, Inositol, Niacin, A-Tocopherol-Acetate, Riboflavin-5-Phosphate, L-Ascorbyl-2-Polyphosphate, Choline Chloride, D-Calcium Pantothenate, Thiamine Mononitrate, Pyridoxine Hydrochloride, Vitamin A Palmitate, Menadione Sodium Bisulfite Complex, Folic Acid, Cyanocobalamin, Chole-Calciferol, Manganese Sulfate, Zinc Sulfate, Ferrous Sulfate, Cobalt Sulfate, Colors include: Beta-Carotene, Red #3, Ehtoxyquin, Citric Acid.


How anyone could read these studies, and conclude that a discus is carnivorous (throughout all life stages) and requires high protein levels in the 50% range (throughout all life stages) or that discus cannot assimilate plant matter, including higher quality aquatic based plant matter such as spirulina, and/or various micro algae, is beyond me.

Yes, there are certain things that one can draw from these various studies that Chong et al have taken part in over the years, there's some great info supplied in all of these studies, and most of it applies to the vast majority of juvenile cichlids.
 
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