Starch in fish food

[mattrox]

Starch is 30 - 55 percent digestible by fish (unooked vs cooked). Simple carbohydrates are easily digestible, but damages the fish's liver if fed in too high levels. So if fed starch, the part that is digested poses a risk to fish. So in foods manufacturers can't use too much starch.

But too much protein fed to fish is a waste. This is the expensive part of the food. The type of protien is important. The mix of amino acids must be correct. The best way to do this is fish meal, but it is expensive. Plant based proteins soy, corn, etc can be suitable substitutes, but then the mix of amino acids must be controlled through which protein source is used.

So a high quality fish meal is 78% protien and very low ash. If this is the basis of a fish food then the percentage protien has to be reduced to 34 - 47% depending on the brand's objective. So now they must add something.... I'll leave this for a moment and come back.

Now in many research papers there are many attempts to improve a 'base' diet. Often the diets are poor as they are in poorer parts of the world. The ingredient that is often changed is starch. One study even used pineapple skins, dried powdered, fermented then used in the food. Invariebly the food performs better by substituting out starch from the base diet. Spirulina, garlic and yeast all improve fish health too.

So my question is, is it the new additive that improves the food or the reduction in starch?

Ok back to where we left off. Lets suppose I use a fish meal has a higher ash content & lower protein content. But it still has the correct protein profile. The protein is still probably too high for my 34 -47% range, so I add starch.

Which food is actually better? No brainer, the lower ash, even though the protien is correct the higher ash will lead to pollution. We know this because well established food companies tell us so, and have done for ages. But are they correct? One of the old addages that don't hold up are feed a flake as a staple, and vary the diet. Flake can lose soluable nutrients very quickly into the water, a pellet is much more efficient. And with the advent of NLS, we have the option of a complete and varied diet out of the tub.

I point this out because 'truths' are often found wanting under scruitny. One that sticks out is the 'all swans are white' example. Europeans for many years held this as a 'truth'.....

So the ash pollutes the water... Hmm so how does that happen. Ash being an all encompassing word for 'all the minerals we just don't test for'. So all these minerals either dissolve into the water or stay insoluable in the solid waste. So we change the water and get rid of them. Perhaps some minerals discolour the water too. But I'm struggling to find pollution, so I'll move on.

So now I'll consider the higher starch, lower ash food. So starch passes through, with a significant amount undigested. To me this is just as much a filler as fibre or ash. But I'll press on.... So the starch passes through in the solid waste too. But starch can be soluable, especially in the large volume of water that is in the aquarium. Lets suppose quite a bit dissolves, to the extent that there is less visible solid waste. Cool less pollution.... Well not quite. Now there is starch in the water we can't see, but bacteria can use as a fuel. Lets suppose they break this down to CO2 and H2O. Waste gone, even better. But how much does this increase the oxygen demand of the whole aquarium? Clearly not enough to harm anything.

But what remains unclear is HOW ash adds to waste. And why is high ash bad, other than 'it has long been accepted'? One reference says that a harmful upper limit of minerals has not been established and that in paricular cases harmful effects were not observed. Now this is an old reference, but much newer than the 'high ash' addage.

So if minerals in food won't directly harm fish. Are they a 'bad' or just 'indifferent' component. Especially if a large weekly pwc will correct mineral balance?

I have been searching for information, but the only thing I can find is high starch could be bad for fish, more so if it is cooked.

In the wash up ash, fibre and starch are all just fillers that are not digested, and a food maker can add starch to lower the ash percentage.

I'd really like to know more about starch in food and the role it plays, other than filler.

[Noddy65]

Oxygen consumption and ammonia excretion of black carp (Mylopharyngdon piceus Richardson) and allogynogenetic crucian carp (Carassius auratus gibelio female x Cyprinus carpio male) fed different carbohydrate diets.

Fish Physiol Biochem. December 2010;36(4):1191-8.

Chun Fang Cai

1

; Yuan Tu Ye; Li Qiao Chen; Jian Guang Qin; Yong Ling Wang

1

School of Basic Medicine and Biological Science, Soochow University, Suzhou 215123, People’s Republic of China. szcfcai@yahoo.com.cn

Article Abstract

Oxygen consumption and ammonia excretion of black carp (Mylopharyngdon piceus Richardson) (4.6±0.3 g) and allogynogenetic crucian carp (Carassius auratus gibelio ♀×Cyprinus carpio ♂) (5.7±0.5 g) were examined when fish fed two types of carbohydrate (dextrin and glucose) at two levels (20 and 40%) each. The diets were isonitrogenous (40% dry matter) and isocaloric at 18.5 kJ g(−1) (dry matter) by adjusting the oil content to 10.1 and 1.5%, respectively. In black carp, the interactions between the carbohydrate type and level were found in oxygen consumption at 3 and 6 h and in ammonia excretion at 6 h after feeding. At 20% carbohydrate, no significant difference was observed between dextrin and glucose in oxygen consumption. However, at 40% carbohydrate, oxygen consumption in fish fed glucose was significantly higher than that in fish fed dextrin at 3 and 6 h after feeding. Within the dextrin diets, no significant differences in both oxygen consumption and ammonia excretion were detected between the two carbohydrate levels. Within the glucose diets, however, fish fed 40% glucose showed significantly higher oxygen consumption than those fed 20% glucose at 3 and 6 h after feeding. Ammonia excretion in black carp fed 40% glucose was higher than that in black carp fed 40% dextrin at 6 h and also found higher than those in the other three treatments at 24 h after feeding. The postprandial oxygen consumption and the ammonia excretion in crucian carp fed 40% glucose were the highest, but no significant differences were observed. Our data indicate that the escalation of glucose to 40% in a fish diet results in high oxygen consumption and ammonia excretion in black carp, suggesting that the efficiency of glucose as an energy source for this fish is compromised by the high metabolic expenditure after feeding. Crucian carp, on the other hand, have a better ability to cope with dietary carbohydrates.

Non-gelatinized starch influences the deposition of n-3 fatty acids in the muscle of a tropical freshwater fish, Labeo rohita.

J Anim Physiol Anim Nutr (Berl). October 2009;93(5):659-68.

V Kumar

1

; N P Sahu; A K Pal; S Kumar; P Sharma; J K Chettri; A K Sinha

1

Department of Aquaculture System and Animal Nutrition in the Tropics and Subtropics, University of Hohenheim, Stuttgart, Germany.

Article Abstract

A 60-day feeding trial was conducted to study the influence of gelatinized (G) to non-gelatinized (NG) starch ratio in the diet on fatty acids profiles and oxidative status in Labeo rohita fingerlings. Two hundred and thirty-four fingerlings (average weight: 2.53 g) were distributed in six treatment groups with each of three replicates. Six semi-purified diets either containing NG and/or G corn starch (42.43%) viz., T(1) (100% NG and 0% G starch), T(2) (80% NG and 20% G starch), T(3) (60% NG and 40% G starch), T(4) (40% NG and 60% G starch), T(5) (20% NG and 80% G starch) and T(6) (0% NG and 100% G starch) was fed to respective groups. Catalase, superoxide dismutase and malic enzyme activities decreased linearly with the increasing level of G starch, whereas reverse trend was found for glucose-6-phosphate dehydrogenase. Total saturated fatty acids in muscle increased with the increasing level of G starch in the diet. Total n-3 fatty acids decreased linearly with the increasing level of G starch in the diet. Among the n-3 fatty acids, linolenic acids content was more in NG starch fed group. Similarly, eicosapentaenoic acid contents gradually decreased with increasing level of G starch content. The n-6/n-3 ratio was higher in G starch fed group. This suggests that dietary starch type may be manipulated for quality improvement of fish flesh.

Modulation of key metabolic enzyme of Labeo rohita (Hamilton) juvenile: effect of dietary starch type, protein level and exogenous alpha-amylase in the diet.

Fish Physiol Biochem. June 2009;35(2):301-15.

Shivendra Kumar

1

; N P Sahu; A K Pal; Vidya Sagar; Amit Kumar Sinha; Kartik Baruah

1

Department of Fish Nutrition and Biochemistry, Central Institute of Fisheries Education, Versova, Mumbai 400061, India. shivdholi@rediffmail.com

Article Abstract

A 60-day feeding trial was conducted to delineate the effect of both gelatinized (G) and non-gelatinized (NG) corn with or without supplementation of exogenous alpha-amylase, either at optimum (35%) or sub-optimum (27%) protein levels, on blood glucose, and the key metabolic enzymes of glycolysis (hexokinase, HK), gluconeogenesis (glucose-6 phosphatase, G6Pase and fructose-1,6 bisphosphatase, FBPase), lipogenesis (glucose-6 phosphate dehydrogenase, G6PD) and amino acid metabolism (alanine amino transferase, ALT and aspartate amino transferase, AST) in Labeo rohita. Three hundred and sixty juveniles (average weight 10 +/- 0.15 g) were randomly distributed into 12 treatment groups with each of two replicates. Twelve semi-purified diets containing either 35 or 27% crude protein were prepared by including G or NG corn as carbohydrate source with different levels of microbial alpha-amylase (0, 50, 100 and 150 mg kg(-1)). The G corn fed groups showed significantly higher (P < 0.05) blood glucose and G6PD activity, whereas G6Pase, FBPase, ALT and AST activity in liver was higher in the NG corn fed group. Dietary corn type, alpha-amylase level in diet or their interaction had no significant effect (P > 0.05) on liver HK activity, but the optimum crude protein (35%) fed group showed higher HK activity than their low protein counterparts. The sub-optimum crude protein (27%) fed group showed significantly higher (P < 0.05) G6PD activity than the optimum protein fed group, whereas the reverse trend was observed for HK, G6Pase, FBPase, ALT and AST activity. Addition of 50 mg alpha-amylase kg(-1) feed showed increased blood glucose and G6PD activity of the NG corn fed group, whereas the reverse trend was found for G6Pase, FBPase, ALT and AST activity in liver, which was similar to that of the G or NG corn supplemented with 100/150 mg alpha-amylase kg(-1) feed. Data on enzyme activities suggest that NG corn in the diet significantly induced more gluconeogenic and amino acid metabolic enzyme activity, whereas G corn induced increased lipogenic enzyme activity. Increased amino acid catabolic enzyme (ALT and AST) activity was observed either at optimum protein (35%) irrespective of corn type or NG corn without supplementation of alpha-amylase irrespective of protein level in the diet.

Gotta get back to work...will do some more searching later

[mattrox]

Thanks Mike.

Those seem to confirm the stuff I read. Simple carbs lead to high blood sugar, protein levels are important. I'll try to get the whole articles and read properly. On the run now.

From my reference digestable carbs should be less than 20% of the diet. I re-read, unkooked starch is 38% digestable and cooked starch is 58% digestable. But these figures are not for mbuna. Mbuna with their long digestive tracts may extract more glucose from the starch. If this is the case foods that use high starch may be detrimental to mbuna. I'm going to look at some food labels and come back.

[mattrox]

Ok, back for a bit.

In the example below the second ingredient is corn starch.

So if all the percentages are added up 39% is unaccounted for. If the assumption is made that all that is carbs, (over estimation) then 38% (digestible) of 39% (max possible carbs) = 14.8% assuming uncooked starch. Now with this food, it does appear starchy, my observation is that the food looks like compessed corn starch, therefore it falls under the 20% digestible limit. This food is also targeted at mbuna and vegetarian tanganyikan cichlids. If these fish with long intestines can actually digest more carbs, then this food may actually not be "the best". If they don't extract more out of these carbs, then it would seem ok.

If the assumption is wrong and the starch has been 'cooked' in the processing then 58% of 39% is 22% then this food does have too much starch. The starch issue to me is of more concern than ash as too much starch does affect liver and kidney function. And this directly influences the fish's health.

Now this example is not trying to discredit a major brand. My hunch is that the starch is a binding agent and is "uncooked" the only issue is do mbuna have the ability to pull more glucose out of the starch. (Starch is just a long chain of a large number of glucose molecules joined together).

I will tackle different examples as I get to them.

[mattrox]

So the next example:

Whole wheat flour is the third ingredient. Undoubtedly this is a starchy food stuff too. So lets add up the percentages, and we see 37% is unaccounted for. If we assume that at maximum there can only be 37% starch (we all know it is less). This food seems "cooked" I know that this assumption is bad, but given previous food discussions, there is enough anecdotal evidence for me to make this assumption.

So 58% (digestible) of 37% (max possible starch) = 21.5% digestible starch. Now this is a concern. From experience we know that fish don't die when we use this food, but we don't have blood glucose levels or tissue analysis either. And if mbuna can extract more glucose out of the starch......

I have to conceed that vitamins do take up some of the remaining percentage, but either way there is considerable starch in the food.

With all the concern about ash, which as far as I can see, too much ash doesn't harm fish. But too much starch can! I do think that the starch component needs just as much scrutiny as ash.

Now, undoubtedly both foods do not pose a risk to fishes health and there are other things that are not reported in the percentages, but it does show that a you can add starch to a food to reduce the ash percentage at the same time to get the protein to the target level of the brand. So this is a manipulation of figures. "Let's lower the ash content buy adding starch".

So is adding starch a neutral or detrimental practise in the long run. Could our fish do even better if starch were not used as a filler? From the reading I am doing I would almost prefer a food with no added starch. Does a food exist that has no added starch or starchy ingrediant like flour?

[mattrox]

Composition

Fish and Fish Derivatives, Algae, Derivatives of Vegetable Origin, Molluscs and Crustaceans, Oils and Fats, Minerals.

Analytical Constituents

Protein 37%, Moisture 19%, Inorganic Matter 16%, Fat Content 7.4%, Fibre 1.8%.

This is taken from: http://www.new-era-aquaculture.com/public-aquariums-and-institutions/professional-tropical-range/rift-lake-cichlid-pellets-green

So lets call the inorganic matter ash just to draw a comparison with previous examples.

When all the percentages are added 18.8% is unaccounted for. Again let's assume (and we all know this is wrong as vitamins make up a percentage) the max starch is 18.8% and this food we will assume is uncooked, based on manufaturers specifications. And we have to trust this just as much as we trust any other maker of food. So 37% of 18.8% is 6.96% maximum possible digestible starch. We know this is an over estimation, but any plant ingredient will add some starch. This is well under the 20% max starch guideline.

Now I am not a supplier or distributor of this food and have no financial advantage by saying any of this, but on a fish health perspective this food looks great. So now the question is: is the " too much ash = excess waste" addage a reality or just one of the things we accept because we hear and say it often enough. Or with our newer 30 to 50% pwcs, do we remove the "waste" more efficiently than the recommendations I remember from the 80's "10-25% weekly pwc as we don't want to shock the fish."

[RD.]

..............

[RD.]

Hopefully this works this time ...........

You are making some rather large assumptions, and using make believe numbers while attempting to force a round peg into a square hole. It simply doesn't work that way, at least not in all cases, with all foods. For a starter, it is virtually impossible to quantify the carbohydrate content, or more importantly its digestibility, by using such a simple analysis as you have. Unless you know the inclusion rate of each component in a formula, there is absolutely no way in knowing what percentage is of what, including the total starch content. It's guess work at best.

As an example, brand A could use 300 pounds of fish meal & this could technically be the "main" ingredient in the food, followed by several terrestrial grains, wheat, corn, soybean, etc.

Brand B could use 300 pounds of krill meal, followed by 300 pounds of herring meal, also followed by some terrestrial grain utilized as a "binding" agent, not a filler, with the rest of the "starch" ingredients being sourced from aquatic plant matter.

A component such as "algae meal" that contains kelp meal, seaweed, and several micro-algae will generally have a high starch content, but that aquatic based starch will not only be far easier for a fish to assimilate than terrestrial based plant matter, it will add FAR more overall nutrient value to the finished product, and contain none of the anti-nutritional matter that is typically found in terrestrial based starch. Kelp meal alone typically consists of 50% carbohydrate/starch. Does that make kelp "bad" for a fish, of course not, unless that's the sole food stuff that one is feeding as a staple.

Using Brand A as an example, a listing in order by weight of; Fish Meal, Corn Starch, Wheat Gluten, and Wheat Flour, could equate to when combined there being more terrestrial grain content, than fish meal in this formula. Is there? Who knows? Unless one is privy to the inclusion rate in each of the listed raw ingredients there is no way in knowing exactly how much the % is of each ingredient.

When a manufacturer pads their food with terrestrial based starch (such as using wheat as the main ingredient, and/or several listings of terrestrial based starch across the board) it is typically done as a low cost source of both energy & protein. This equates to the more costly animal based protein such as fish meal etc being spared as an energy source at all costs. It is for this exact reason why the commercial fish farm industry spends so much time studying alternative protein sources to replace some of the fish meal in their formulas. This is not being done in the pursuit of "better" feed for their fish, it's being done in the hopes of making less costly feed.

Think of it this way, if you ate a loaf of white bread every day along with the rest of your diet (more bread, less quality nutrients) you would still grow, and become larger, it just wouldn't be healthy growth. Overtime you would become obese, and by the time it's showing on the outside, the inside is already suffering damage.

This is no different in fish, I see obese fish all the time, mostly caused from overfeeding, but sometimes from feeding diets that contain excessive starch content. Quite frankly IMHO many people in this hobby do in fact overfeed their fish, in the misguided notion that they can force faster growth, reproduce quicker, or just because they feel their fish are hungry. Fish are always hungry! lol

Yes, one should not feed excessive starch to a fish, we've known this for decades, and while starch is not an essential component in a fishes diet, it can play an important role when utilized properly. FYI - all starch used in commercial food is "cooked", unless one is feeding raw food. The cooking/extrusion process actually makes most carbohydrate more digestible for fish, and in the case of terrestrial based starch, the cooking process destroys most of the anti-nutritional factors.

To state that ash content is a non-issue in fish food would be the same as saying that total digestibility of the food is a non-issue.That make absolutely no sense whatsoever. Any part of a diet that can't be fully assimilated or utilized by a fish is waste, and ultimately that waste adds pollution to one tank water. Period, end of story. While no food will be 100% digestible or 100% bio-available to a fish, that should be the ultimate goal.

You asked how ash adds pollution to ones tank water - isn't it obvious? This is the same as asking how do dissolved organic compounds (DOC's) add pollution to ones tank water, or how do phosphates add pollution to ones tank water. Or should one consider those non-issues as well? Of course not! Certainly we can control these elements via regular water changes, but that doesn't mean that we totally ignore their presence in a closed system such as an aquarium.

While ash content may not be a primary consideration when evaluating feeds, it should always be considered, as should carbohydrate/starch levels, as should total digestibility, and the total bio-availability of every nutrient in the food.

This isn't some simplistic mathematical equation where one can just punch in some numbers & come up with the "best" food, value wise, nutrient wise, or anything else. While fish labels and their guaranteed analysis, ingredient listings etc offer the general consumer a good general guideline to go off of, they are nothing more than a general guideline as to what the food in each container has to offer. Long term feed trials are the only way that one can truly differentiate between what food is "best" for their fish, their wallet, and their overall personal situation.

[mattrox]

The percetage digestablity of cooked and uncooked carbohydrate is established (for trout anyway) and as I said it would be interesting to see how these values vary. But data from one species is used all the time to make assumptions for other species in published papers. So I don't see how I'm drawing a long bow in this instance.

Textbook of Fish Health 2nd End. pg 230.

And when you add up percentages the only components left out in the examples is carbohydrate and the vitamin content. I did qualify and say maximum possible carbs. I know that the filler starch is added to reduce costs, its sensible to reduce costs. I know that they need to bind food togther and starch does this well. But do they NEED is add stach at all, if so why not add less? Other than with less added starch, their precious ash % increases.

No doubt any plant source adds different amouts of carbyhdrate. But I don't have to work out the carbs from each source. All I am interested in with this exercise is the total carbs. I did make some assumptions. But they can't be too far off. I am safe to assume that the manufacturers are not using simple carbs like glucose and dextrin as they are highly digestible and bad for fish. For this excersise carbs are: sugars, starches and cellulose. Cellulose is not very digestible(10%), and since this is reported as fibre in the analysis it has been ignored. If I am VERY wrong about total carb content, what is the remaining 39%, 37% and 18.8% respectively? Ash, protein, fibre, fat, moisture..... apart from vitamins which are added in mg per kg amounts, what else is there that makes up the bulk in the food? It's not a long bow to draw when the second or third ingerdient is a carb source, that a significant amount of the "missing" percentage is carbohydrate. And since this is a fish forum and not a scientifi paper, I'm not going to trot down to my local diagnostic lab and obtain an exact analysis.

The recommendation of no more than 20% digestible carbs is from the above reference too. And using my rubbery figures, it would seem that manufacturers know this. Adding corn starch does not add protein, wheat flour and corn meal does. The former would be almost 100% carbs and the latter I haven't looked up, but are sources of carbohydrate.

In terms of protein, vitamins, minerals etc I believe the foods I am using are filling the fishes needs so I wasn't ignoring that aspect of fish health.

In terms of the ash, if they are bound up in insoluable parts of fish waste then they are in the poo. If they are soluable they are in the aquarium water. Of course this is "pollution" but no more pollution than the solid waste consisting of fibre, undigested protein, insoluable carbohydrates already in fish poo. I would argue that the larger water changes that are the routine these days take care of pollution no matter what the source. Compared with the 10-25% figues I remember from the past. I can go find some old books to check this.

If a food were 37% protein and the rest added raw minerals, of course that makes the food less digestible. But when algae, yeast, garlic, vege extracts etc etc are added, the mineral (ash) are mostly in the added ingerdients. When using whole ingredients to provide the mineral needs the ash itself is not going to decrease diestibility. There is ample evidence that at optimum protein levels and amino acid profile, the actual source of the protien is not so important.

I guess what I am trying to highlight it that foods do not report the carbohydate content of their food. I would ultimately like the least amount of carbs possible because of the increase in blood sugar levels leading to liver and subsequently kidney damage. I think it is worth thinking about how much carbohydrate is in the product when selecting food. A lower carbohydrate content would seem to be more desireable.

And if the starch is cooked in the first example, then I would not be too far wrong in saying that the food is pushing the maximum carbohydrate level a food should have. The 58% digestibilty figure is not made. I didn't grab it out of thin air.

Previous food discussions have revolved around protein levels and ash content. But as you say there are lots of factors involved. This is what I meant by ash is not the be all and end all of a food evaluation. The 'non-event' comment was designed to stimulate debate and of course ash must be considered. But considered in the context of other ingredients. I can "artificially" reduce ash% by adding starch. I would argue that in that case the higher ash content and less starch may infact make a better food.

[RD.]

But do they NEED is add stach at all, if so why not add less? Other than with less added starch, their precious ash % increases.

If you stopped viewing this with such tunnel vision, you might actually begin to understand how silly some of this is. Manufacturers are not even required to list ash content on a fish food label, so if high ash values are a concern, or for whatever other reason a manufacturer decides, they can simply leave ash off of their labels. Many prominent fish manufacturers do just that. That should put an end to any further conspiracy theories. The bottom line is, the higher the ash value, the lower the total nutrient value to the feed.

Does starch need to be added, well I guess that depends how you feel about ingredients such as kelp, seaweed, spirulina, Haematococcus pluvialis (astaxanthin) and several other micro algae that ALL contain starch. Some of these algae are actually now being utilized in fish food so that less terrestrial based starch is required as a binding agent. As far as nutrient value, clearly not ALL starch is created equally.

But data from one species is used all the time to make assumptions for other species in published papers. So I don't see how I'm drawing a long bow in this instance.

And that my friend is exactly why sometimes a little bit of knowledge can be a dangerous thing.

You are comparing a coldwater species such as rainbow trout with studies involving terrestrial based grain, to warmwater tropical species of fish being fed aquatic based plant matter.

You simply cannot extrapolate the information from the former, to the latter.

From the NRC's Nutrient Requirements of Fish, which is pretty much the bible for every commercial fish food manufacturer. Not the be all to end all, but a great reference source to work off of for tropical species.

The nutritional value of carbohydrates varies among fish. Warm-water fish can use much greater amounts of dietary carbohydrate than cold-water and marine fish. No dietary requirement for carbohydrates has been demonstrated in fish; however, if carbohydrates are not provided in the diet, other compounds, such as protein and lipids, are catabolized for energy and for the synthesis of various biologically important compounds usually derived from carbohydrates. Thus, it is important to provide the appropriate concentration of carbohydrate in the diet of the fish species being cultured.

From a USDA paper on Rainbow Trout;

At the same time, we also raise new questions about the upper limit of feed levels of carbohydrate in this species. Depending on the source and quality of dietary carbohydrate, the aquaculture industry standard of 20% carbohydrate represents a "conservative" value. We documented outstanding growth performance of trout receiving 24% (mostly wheat flour) or even 30% (mostly purified starch) fed aquaculture rations or to satiety, respectively.

Also keep in mind that in almost every feed trial involving commercial fish such as trout/salmon etc, the fish are fed to satiation levels, usually twice a day - something that none of us are doing in our aquariums. Hopefully most hobbyists are not stuffing their fish to the gills 2-3 times a day just to see what the upper levels are with regards to digestion, absorption & digestibility of their feed.

And again, the upper limit of 20% carbs" is referring to coldwater species, where terrestrial based ingredients such as corn, soybean, etc are being utilized in the feed trial, not algae based ingredients. This is due to the latter being too cost prohibitive in a commercial farm setting. Check the cost of a high grade spirulina such as what Cyanotech Corp. produces, next to corn starch from a producer in China, then get back to me.

The problem with carbs is that unless they are used immediately as an energy source, they get stored as glycogen, and eventually converted to sugar, and then fat. This is exactly why one can find some VERY large obese specimens that have been fed generous amounts of lower quality high starch food. No different than a human that eats a large amount of white starch. (bread) You will still grow, and get big, but eventually become obese. If you are concerned about an increase in blood sugar levels leading to liver and subsequently kidney damage - then simply use feed that doesn't contain massive amounts of terrestrial based carbohydrates, and just as importantly - control how much you feed your fish! I can take the exact same food that's fed a fish, dog, cat, monkey, or whatever, and cause all of the health problems that you are apparently concerned about, and then some, by simply overfeeding. Even a very healthy diet, can become unhealthy by overeating.

That doesn't mean that we should seek out foods that contain 0% starch, only that one should not be feeding foods that contain excessive amounts of starch, especially terrestrial based starch, especially to those species that fall on the carnivorous side of the equation as those species have lower limits when it comes to carbs.

But again, this is all old news to anyone that's been involved in aquaculture for any amount of time.

[mattrox]

Which is all great, but the carb sources in 2 of the foods above are not entirely aquatic, one has corn starch the other is wheat flour lower on the list.

And I know there will be differences between cold water and warm water fish. But you have to look at the data already available.

And mbuna have a strong chance of digesting more starch. To me this would be a bad thing when looking at the levels of some carbs in foods.

Improving growth performance is one thing but blood sugar levels and liver and kidney another. Growth performance is not something I'm interested in with my adult fish. I want well functioning organs.

Don't use the 'little bit of knowledge' line. Because all scientific endeavour starts from a known point then makes some assumptions (hypothesis) then the hypothesis is tested.

I would really like to see data on the condition of the liver and kidneys of mbuna fed 'high' carb diets. I don't have that on hand. The facts I do are that too much starch caused organ damage in fish.

This is why I asked. I'll just need to do more reading and a wider literature search.

[mattrox]

And I really don't see it As tunnel vision. Starch in an existing whole ingredient is different than adding corn starch. And that is what I was referring to.

Clearly I'll be choosing which foods I use carefully. But I was suprised to see corn starch high on the ingerdient list of a reputable brand of food targeted at mbuna and other vegetarian fish. This is what got me wondering about starch levels and how much is actually in the food and the implications. Now this food's appearance is not like the extruded and baked type foods. It looks and feels like it is powder pressed like a pill is made with dry ingerdients. I know that this is a major assumption, but others using the food are free to comment.

[RD.]

mattrox .......... I have been speaking about the potential health issues caused by high lipid & high carb inclusion rates in fish feed long before Al Gore invented the internet. I've been in this game a long time, have been studying fish nutrition for decades, and have a very firm grasp of what it takes to grow out a healthy fish, with longevity in mind.

I'm not here to argue, or have some kind of debate, I'm posting here in an attempt to help you understand some of this better. .

My advice would be to get your hands on a copy of the NRC's Nutrient Requirements for Fish, and if you are going to compare commercial species to your Mbuna, at the very least extrapolate the information supplied for Tilapia, a warmwater herbivorous species of cichlid, NOT rainbow trout, a coldwater carnivore.

Then you have to consider the source of starch in these types of comercial aquaculture studies, where terrestrial grain is typically what's being utilized, then consider the exact type or form of these grains, then you have to consider the amount of feed going into these fish 2-3 times a day (fed to satiation) and then you also have to factor in the life stage of the fish, the temperature of the water, and even the longevity of the feed trial. Most are only based on a few weeks, not years.

Here's a good starting point that is a more accurate reference when considering a herbivorous warm water species, such as your mbuna.

http://web.macam.ac....IJA%20-1997.pdf

Abstract:

The digestibility of various diet components as protein and carbohydrate sources for adult tilapia (Oreochromis aureus x O. niloticus) was studied by using an inert marker in the feed and collecting the feces by stripping. Each experimental diet consisted of a different protein and carbohydrate source (50%) plus 50% reference diet (50% soybean meal, 35% wheat flour, 10% soybean oil, 5% vitamins, egg yolk, guar and chromic oxide). It was found that the apparent digestibility of protein in fish meal was 90%, in soybean meal 95%, in poultry meal 92% and in wheat flour 91%. Energy digestibility tests gave the following results: 18.09 kj/g for fish meal, 15.58 kj/g for soybean meal and 16.9 kj/g for poultry meal. The digestibility of carbohydrates was 93% for wheat flour, 81% for corn meal and 85% for barley meal. The figures for digestible energy were 17.51 kj/g for wheat flour, 15.42 kj/g for corn meal and 14.36 kj/g for barley meal. The differences in the digestibility of various protein and carbohydrate sources are discussed.

and another ........

http://onlinelibrary...+IT+maintenance.

Abstract. This paper examines the digestibility of different feed mixtures by three species of fish: carp, Cyprinus carpio L., tilapia, Oreochromis aureus×O. niloticus, and African catfish, Clarias gariepinus (Burchell 1822). Protein from poultry sources was digested better by tilapia than by carp or catfish, but no significant difference was found in the case of protein mainly from fish meal. Carp showed the best ability to digest fats, followed by catfish, with tilapia having the least ability. Tilapia digested carbohydrate better than the other two species, however, whether from wheat or corn sources. The same pattern applies to the digestibility of energy.

As demonstrated in numeorus studies, Tilapia can utilize carbohydrate very efficiently, but their ability to digest fat is not nearly as efficient as many other species of fish. A classic example of how incorporating starch into the diet of some species of fish can sometimes be very effective.

Non aquatic based carbohydrate such as wheat flour when used at appropriate levels will not cause any type of negative health issue in a fish. I don't need to post a hundred studies to support that fact, I have personally raised numerous species of fish on one of the commercial foods that you pointed your finger at previously, omnivores, carnivores, and fish classified as strict herbivores, including numerous species of mbuna. If a fish lives a long healthy life of a decade or more on that diet I think it's safe to assume that blood sugar levels were not off the chart, nor were the fish suffering from liver or kidney damage. 8-10 years is a typical lifespan for most captive raised mbuna, haps, peacocks etc, and I think that's a pretty good longevity feed trial. Been there, done that, and then some.

If some of the assumptions that you have made were actually true I suspect that these fish wouldn't have made it to the 12 month mark, let alone a decade or more of being fed this particular diet, exclusively.

Aquatic based plant matter, such as spirulina, kelp, micro-algae, etc. when used at appropriate levels will also not cause any type of negative health issue in a fish. I used the term tunnel vision due to your lumping of ALL carbs together, as though they are all equal. Clearly they are not. Even terrestrial based carbs are not all equal when it comes to digestibility, anti-nutritional matter, etc. And also as previously mentioned, even fish meal contains some carbohydrate, as does krill meal, shrimp meal, etc. When a manufacturer incorporates various fruits, vegetables, and aquatic plant matter in some of their listed ingredients, this will obviously raise the overall carb content in the feed. While these components will elevate the overall carb content, they also supply key vitamins and minerals, and key bio-active compounds that add to the overall nutrient density of a feed.

Ingredients such as Spirulina, Kelp, Seaweed, Micro-Algae, Garlic, and various fruit & vegetables all contain bioactive compounds, that 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. These are not compounds that can be created in a test tube, and then added as a supplement, they come from the raw foods themselves, which generally also increases their bio-availablity to a fish. These types of ingredients are a key element in creating a nutrient dense premium pellet feed.

Carbohydrate is not the enemy. Massive amounts of terrestrial based carbohydrate can indeed be a problem, we all know that, decades of studies have proven that, especially with most carnivorous species - but this does not mean that one should throw the baby out with the bath water.

In commercial aquaculture a "high carb" diet would typically be one that consisted of 50% or greater carb content, and that utilized 100% terrestrial based grain as the source of carbohydrate. Not aquatic based carbs such as algae meal, spirulina, kelp, etc. This fact is of key importance if one is going to make assumptions from information gleaned from aquaculture studies involving commercial species of fish that are raised for human consumption. Just like all other components that make up a premium fish food, with regards to carbohydrates it's all about balance.

HTH

[malrift]

can I ask wouldnt using fruit and veg ingredients be the same as wheat and soy as they are both terrestial based?

Ok besides the vitamin impact of those ingredients. Also read a studyy on garlic used in fish foods that has been showing signs of liver problems when over used? Can you tell me if it is true or just simply a story conjured up as we often see.

[RD.]

While fruit & vegetables are indeed terrestrial based, they differ from what is typically utilized in fish feed as most do not contain the types of anti-nutritional matter that is found in soybeans etc. This is precisely why I have repeatedly stated that not ALL starch is created equally.

Again, it's all about balance. Frugivorous species of fish at certain times of the year, and/or life stages, may consume as much as 70-90% fruits, yet like most species of fish they are capable of adapting to other food sources, such as various prey of animal origin (snails, vertebrates, anthropods, etc), and/or aquatic plant matter. Most fish in the wild are opportunistic feeders, they do not turn up their nose at a free meal, no matter what that meal may consist of. There is also a major difference between mammals & fish when it comes to the regulation of blood glucose, fish have a far greater tolerance to wide fluctuations of blood glucose levels. This doesn't mean that one should stuff their fish with carbs, but at the same time it does not mean that carbs should be completely removed from any fishes diet.

As far as garlic, the only true scientific study that I'm aware of where a negative conclusion was reached when feeding garlic (a purified form of allicin) to marine fish, was due to terrestrial based lipids being bad for a fish, which is true, if used in excess. A potential problem if one uses fresh garlic or garlic oil over an extended period of time, a total non issue if one uses a commercial feed where garlic powder is being used. A very important part of that equation had been left out, that being the inclusion rate of lipids via the addition of adding garlic to most commercial feeds (@ 1-5%) wouldn't even register on the overall lipid percentage of the food.

I don't know of any manufacturers adding massive amounts of garlic to their commercial feed and with regards to commercial foods, the "lipid" content derived from the garlic used in most formulas (garlic powder), would be almost nonexistent. Something along the lines of 0.0001%

To think that this will somehow have negative effects on the health of a fish, be it short term, or long term, due to the lipid content, is quite frankly, ridiculous.

Using this same type of logic one could make the same accusations about Vitamin A, due to the fact that at high enough levels it too can become toxic to fish.

Many scientific studies are performed with preconceived notions, and that bias can often times taint the validity of the "scientific" conclusions. In the garlic study mentioned above it was crystal clear to me that the scientist involved in this study had for whatever reason lost his objectivity. IMO, this "study" was a complete farce, other than it supported a well known fact, that being that excessive terrestrial based lipids are generally not healthy for most species of fish. Nothing we didn't already know 30 yrs ago.

[mattrox]

I wasn't "pointing the finger". I was just using what I had at hand. And as it turns out, I am uncomoftable with the starch level of one of them for the long term use in my fish room.

I know that no component in food is classified as "good" or "bad". I was wondering why an extra stach souce (ie corn starch) would be utilised, ie a binding agent, filler, reduce cost, reduce the % ash as a marketing tactic etc. And I don't buy that a corporation would not use "marketing tactics" when designing a food.

I can understand that suppliying energy for the physical activity for fish through carbohydrates allows them to utilise protein (the expensive part) for growth reproduction etc. And again, I'm not so concerned when the carbs end up in the food through the addition of other plant based material. And I am not having a go at manufacturers. I have just become sceptical about the addition of corn starch as a major ingredient. I understand that wheat flour has gluten (protein), minerals (ash) and starch in it and similar for ground corn.

And while you have been talking about starch for a long time, I am struggling to recall any serious discussion about starch. I have too been fish keeping a long time, and I love reading, books, texts and more recently papers etc. Most of what I have read and been interested in has been species information, breeding, water chemistry etc, it's really in the last 4 years that I have been more interested in foods. And since I built the fish room and am looking after hundreds of adults at and numerous fry, this has been much more relevant to me. And the only information I have ever been given has been of a general nature "Feed a flake as a staple and suplement with a variety of food", "make sure the protein levels of food are appropriate". I have also been on various forums for longer than I care to remember, and I have never once seen a thread on starch. To me this is just as important as regulating protein levels.

Plenty (almost all) talk about protein in isolation of all other ingredients. And I don't think it is at all unfair to discuss carbohydrates, particularly when added from a source high in starch. And from the beginning I said I was making some assumptions about the "max" levels. I also said I was partularly interested in the 100% starch and other high starch ingredients. It is plain as day on the label. You seriously couldn't make me believe, that when corn starch is number 2 and wheat flour is number 4, that the bulk of the carbs are coming from parsley, spirulina algae meal, stinging nettle meal, herb... etc which start at number 8. These high starch ingredients are high on the list.

I also do not have a simplistic view of foods. I understand the chemisty and biology of food. While I don't claim to be a nutritionist, I do understand the science. I can also read, accurately interpret and understand a scientific paper.

Aquaculture provides a useful source of information about foods. The difference between aquaculture and my fish room is that the fish they want to grow up quickly are destined for the table in a short period of time. I want my fish to live a long time. I haven't come across any study on the chronic effects of cabohydrates on aquarium fish. Perhaps some of the foods we use are effective in growing our fish fast, but may decrease longevity. And I think that question is entirely valid. I am not talking about short lived species so I feel that it is valid to ask questions.

Given that information about carbs is not listed, I have to start somewhere. When a high starch ingredient is high on the list and the carbohydrate content appears high I think it is fair to raise a couple flags. If all the ingredients were algae, kelp, spriulina (the food would be more expensive) the carbs are not being delivered in a raw form that is more easily converted to glucose. Its the potential quick increases in blood sugar levels, and chronicly high blood sugar levels that I would be worried about.

And I am not just imagining up possible scenarios, and telling fairy tales either.

[mattrox]

I just looked up wheat flour just to make sure I'm not off track. ~ 76% carbs total but ~2.4% is fibre so ~73% starchy carbs. and ~10% protein.

[RD.]

Its the potential quick increases in blood sugar levels, and chronicly high blood sugar levels that I would be worried about.

Please go back & read my previous post to malrift. That should help alleviate some of your concerns about blood sugar levels, in fish.

Yes, of course wheat flour is a starch, and your point is? This is precisely why it has been utilized for several decades in commercial feed, its only role in fish feed is that of a binding agent. Without it, your pellets would simply not hold together. But that doesn't equate to those pellets containing a massive amount of wheat flour, that is somehow going to cause chronically high blood sugar levels in anyones fish. lol

While overall your concern about excessive starch is a valid one, you're starting to remind me of the scientist that stated that any garlic is bad for fish due to the terrestrial based lipid found in garlic oil.

If you don't want your fish consuming corn starch, then simply stop feeding that food.

Problem solved.

As far as finger pointing, this is what I was referring to.

Now this is a concern. From experience we know that fish don't die when we use this food, but we don't have blood glucose levels or tissue analysis either. And if mbuna can extract more glucose out of the starch......

If you have some actual data regarding this food, and mbuna, or any other species of fish, to support your comment quoted above then please feel free to share it with the rest of us. My long term feed trials involving this food (over a decade with mbuna alone) tends to remove any concern about blood sugar levels, and/or potential damage to a fishes liver.

[mattrox]

and that's precisely what I was questioning. Is what we have been doing for decades the best practise?

For decades feeding beef heart was considered good practise. I would say that is no longer considered best practise.

Asking questions about current methods is surely the way new developments happen. NLS would not be here if questions about better meeting nutritional requirements for fish were not asked and investigated.

The point of this is not to bash particular brands, or even say a particular ingeredient is bad. But surely it is valid to question the quantities used.

Moreover, in the process of investigating this, I have found a food I personally would not buy anymore.

[E4G13M4N]

and that's precisely what I was questioning. Is what we have been doing for decades the best practise?

For decades feeding beef heart was considered good practise. I would say that is no longer considered best practise.

To be honest (my opinion) i dont ever recall beefheart being considered as best practice, other than to grow and put weight on discus quicker but in most circles was never considered a great food for fish in general, but like most things its just hard to change some peoples opinions on beefheart.. But that is a different debate

[RD.]

Personally I have never considered feeding beef heart to fish a good practice.

But I get what you're saying, and a manufacturer that actually cares about the quality of feed that they manufacture should always stay up to speed with the current science. I have no issue with anyone who asks questions, I'm the original sceptic. But sometimes when something works well, very well, at the end of the day that's all that really matters.

Wheat flour works well, very well, and unlike many other substances that can be utilized for binding a pellet feed it has withstood the test of time. Wheat flour certainly isn't the cheapest option for a binding agent, there are far cheaper alternatives, but when one starts to compare feed efficiency values, water stability values, etc, even today wheat flour is still at the top of the list.

This is not to say that there aren't other good options, even aquatic plant based options, so just because you see wheat flour up front, doesn't mean that there aren't other ingredients at play working in the background jn conjunction with that wheat flour. Utilizing some of these other options can allow a manufacturer to reduce the terrestrial based starch to even lower limits than used in the past. While the order of the ingredient listing may not have changed on the label, that doesn't mean that a reduction of the inclusion rate hasn't taken place. And without getting into specifics, that's all I'm willing to say about that.

Sometimes one needs to read between the lines, and think outside of the box, and not simply rely on numbers & percentages.

[mattrox]

Perhaps, I should have worded good practise as 'accepted practise'.

I'll have to duck into the uni library at some stage and get my hands on this paper.

Effects of dietary starch and energy levels on maximum feed intake, growth and metabolism of Nile tilapia, Oreochromis niloticus

Aquaculture (2008

byAn Tran-Duy, Ben Smit, Anne A Van Dam, Johan W Schrama

Abstract

The aim of this study was to gain insight into how Nile tilapia (Oreochromis niloticus) regulate feed and energy intake in response to diets low and high in starch and cellulose. It was hypothesized that high-starch diets would reduce feed intake due to the effect of high blood glucose level, and that stomach volume may limit feed intake of fish fed diets low in energy. Four experimental diets, low starch-no cellulose inclusion, high starch-no cellulose inclusion, low starch-with cellulose inclusion, and high starch-with cellulose inclusion, were formulated. The high-starch diets and diets with cellulose inclusion were 17.5% more energy-diluted than the low-starch diets and diets without cellulose inclusion, respectively. Male tilapia were fed to apparent satiation for six weeks. Feed and digestible energy intake of fish fed diets with cellulose inclusion increased and decreased by 8.3% and 5.5%, respectively, compared to fish fed diets without cellulose inclusion. This suggests the role of stomach volume in restricting feed consumption. Fish fed high-starch diets achieved only 0.5% more feed intake and 13.9% less digestible energy intake than fish fed low-starch diets. The lower increase in feed intake and higher decrease in digestible energy intake of fish fed high-starch diets than of fish fed diets with cellulose inclusion suggests that high blood glucose suppresses feed intake in Nile tilapia. An alternative explanation for the differences in feed and digestible energy intake of fish fed different diets was based on the fact that heat production was not influenced by starch nor cellulose-inclusion levels. Thus, under satiation feeding, oxygen uptake capacity may determine feed and digestible energy intake in fish rather than blood glucose or stomach volume.

[RD.]

Beef heart has no relevance to this discussion. I have personally never considered feeding a fish beef heart to be a good practice, or an accepted practice, and have been speaking out against the feeding of beef heart to fish for as far back as I can recall. As far as "accepted" goes, it is still widely accepted by millions of discus owners world-wide, where quick gains in growth seem to be more important than long term health. But as E4G13M4N previously stated, that's another debate altogether.

As far as the paper above, do you understand what the term satiation means?

I've mentioned this term a number of times in this discussion, but it appears that perhaps you still aren't picking up what I'm laying down? See below from a previous comment in this discussion;

Then you have to consider the source of starch in these types of comercial aquaculture studies, where terrestrial grain is typically what's being utilized, then consider the exact type or form of these grains, then you have to consider the amount of feed going into these fish 2-3 times a day (fed to satiation) and then you also have to factor in the life stage of the fish, the temperature of the water, and even the longevity of the feed trial. Most are only based on a few weeks, not years.

And add to that 02 levels in the water, something that I missed in my previous comment.

From the paper cited above;

Thus, under satiation feeding, oxygen uptake capacity may determine feed and digestible energy intake in fish rather than blood glucose or stomach volume.

How on earth can a paper such as the one that you just cited have any bearing whatsoever on the fish that you keep in your aquarium? Are you feeding your fish until they simply refuse to eat anything further (satiation levels)? Is anyone else here? Of course not!

Fish primarily eat to satisfy energy requirements. If too much energy (starch) is supplied compared to protein, most fish will stop eating before enough protein has been consumed for optimum growth. A rather counter productive feeding strategy if growth parameters of the fish is of any concern, which clearly it always is. I don't think that too many fish feed manufacturers set out to develop massively high starch foods where a fish will show poor growth compared to the competitions food.

When compared to the fish that we keep in our aquariums the hypothesis of the study above is invalid before it even begins, due to the simple fact nobody in their right mind is feeding their fish to satiation levels twice a day.

The moral of this story is a simple one, do not stuff your fish!

In the wild fish barely eek out an existence from one day to the next, and are rarely swimming around with a belly stuffed full of high energy, high protein, nutrient dense food. For anyone that is truly interested in extending their fishes life in captivity, control the amount that you feed your fish, especially if you are feeding a more premium nutrient dense diet. I have yet to see a freshwater fish that's kept in captivity die of starvation, but I have seen plenty of obese cichlids.

The key to feeding fish is to ensure that all of the nutrient demands are being met for growth, reproduction, normal day to day metabolic functions,etc, but to not overly exceed those nutrient demands.

The nutrient demands can vary from species to species, and even fish to fish. An active high-energy species such as most mbuna, per body weight will generally require more nutrients than a large CA cichlid that floats around like a log all day. Both fish can eat the same food, but in this case the former will require more nutrients per body weight than the latter. While most commercial feed applications are indeed based on science, a lot of what we do in our own tanks, with our own fish, simply boils down to common sense & with time experience.

When it comes to carbohydrates, primarily terrestrial based grains, my advice is the same now as it's always been. If you see wheat as the main ingredient, that should be a no-brainer. If you see a multitude of grains listed via ingredient splitting; such as wheat, wheat, wheat, corn, corn, corn, soybean, soybean, soybean, or a combination of several terrestrial based starches listed across the board, chances are the starch in the food combined may equate to starch being the main ingredient in the food. Again, a no-brainer - avoid that food. Typically one will not run across this in the more premium brands of food that have surfaced over the past 20 yrs, but more so in brands that have been around for the past 50-60 yrs where they can safely rely on their massive market share, brand name recognition, and multi-million dollar advertising campaigns.

I think that for now I have said about all I can say on this subject, or at least as my time permits. lol

Happy Holidays everyone!

[mattrox]

I know what saitation mean. I know we don't feed to saitation in our aquariums. None the less, I'd like to read the paper and see the results of the experiment, I think it would shed some light on the subject. Maybe, feeding to satiation is to ensure they can observe the effects of the starch. This is precisely what I'm interested in. And with regards to oxygen levels, water can only hold so much oxygen, and I would like to see how the experiment was conducted, were there depleted oxygen levels contributing to their results or was there plenty of aeration? The abstract can't tell me all the information I want to know. Surely by reading the paper, my understanding of starch in the diet is not going to diminish, it seems that you are asserting that reading the results of such research is a waste of time, I shouldn't bother and just trust the foods.

I totally agree about balancing the nutrients and best fulfilling the requirements of the fish. That has never been in question.

I don't think fish food manufaturers set out to provide an inferior product, but the finance department might often exert some influence to cut some costs. Not every food manufactured is equal and to completely ignore the starch content and just trust a brand is just as silly as completely ignoring any other component of the food.

I am pretty sure that some hobbyists would like to know if a food they are feeding potentially has a high starch content, given that aspect of the food is not reported on the label.

Some starch will bind the food, add some more to provide energy so protien is not "wasted" as an energy source and can be used for growth and reproduction. But at some level the carbohydrates become a cheap filler, and at what levels are they excessive and have the potential to have adverse effects on a fish's health? That is what I am trying to find out. I have incomplete information and I know that, but I have to have a starting point. And all of the information I have cannot be considered completely irrelevant just because the conditions are not exactly the same as the studies that have been completed.

[RD.]

mattrox ............. There were no hidden subliminal messages in my previous comment, just some sound advice from someone that knows a thing or two about fish nutrition. Utilize that information, or totally ignore it, choice is yours mate. Best of luck with your research.

Cheers!