As much as I would love nothing more than to ignore what has become a total farce of a discussion, I find it impossible not to respond to certain comments that have been made.
And just for the record, Rich, I was in no way attempting to disparage you personally. I'm sure that you're a nice guy, in this case you simply do not know what you are talking about & have gotten way in over your head.
My "job" as you put it, is to promote sound husbandry practices, nothing more, nothing less. I'm just trying to keep things real.
And just to remove any doubt about that, I presented you with a link that involved piscivores, and feeding live vs pellets, that involved two well known unbiased forum members who happen to specialize in the raising & feeding of various gar species. You have repeatedly ignored that thread & the input from those two forum members (now quoted above) since the beginning of this discussion.
Those two individuals probably have more hands on experience with raising & feeding large piscivores in captivity than you & I combined, and more importantly neither have any dog in this fight. They don't sell feeders, and they don't sell pellets. They also have the science available to back up their hands on experience, so who better to utilize in this type of discussion? Seemed like a no brainer to me, if one was actually interested in the truth. Now somehow they too are biased? Right. Those comments were made based on science, commercial experience, and most importantly as hobbyists who actually keep piscivores in aquariums.
And that is exactly what my comments have been based on. I have personally raised enough piscivores in captivity to understand that in many cases one does not need to feed live feeder fish in order to get excellent gains in growth & overall health. Not that one can't, or shouldn't, but that in many cases (as in with some species such as gars/pikes/musky once the fish reach a certain life stage) one doesn't have to in order to get excellent results in both growth and overall health.
Wiggle's experience sums thing up nicely, what can & will work for each hobbyist will depend on their personal situation. If one is keeping large predatory species in outdoor ponds it makes perfect sense to stock those ponds with species of fish that those predators can prey on.
Rich, you state;
we have established that goldfish are in fact a high protein low fat diet.
Really, and where/how did "we" establish that? That proximate analysis on the goldfish that you provided came from a
single paper, where a
single goldfish specimen was used in their analysis. That doesn't establish anything, other than a desperate to attempt to prove a point. While what you say may indeed be true, I think that "we" will require a bit more than just a single analysis on a single goldfish to establish anything.
The reason you don’t see high growth rates with commercial diets is that they don’t provide a high quality source of proteins and other essential nutrients. It’s that simple.
Who exactly isn't seeing high growth rates, Rich? You obviously haven't spent any time perusing this forum & checking out all of the monster fish owned by members here, many that have never eaten any form of live food. Please share with the readers here exactly what amino acids, fatty acids,vitamins & trace minerals, and/or other essential nutrients are being supplied by feeding a goldfish, that are missing in all commercial diets. I'm sure that everyone would love to know.
You talk a big talk yet provide zero proof to support your outlandish claims of nutrient superiority.
I asked you in my initial comment in this thread; What "best science" do you have to support that? One would need to compare amino acid profiles, fatty acid profiles, total vitamin & trace mineral content, total digestibility, feed conversion ratios, color enhancing properties of the feed, a comparison of potential bioactive compounds contained in the food source, which in aquaculture have been shown to have biological effects in fish such as growth promotion, immunostimulation, anti-stress, anti-bacterial, anti-fungal, anti-virals. etc-etc-etc
This is exactly what professionals in commercial aquaculture do, and yes, cost of the feed is a major fact as well. You toss out numbers such as $20 a pound, yet if one buys commercial feed in bulk it can be purchased for as little as $2 a pound, or less. It all boils down to how high in quality one wants to go, and how much they are willing to pay for that quality. Even today's super premium brands when purchased in bulk containers cost half the amount that you quoted.
As I have stated repeatedly in this discussion, I have no problem with those that choose to feed live foods, but to state that other options are ridiculous alternatives, is well, ridiculous.
As Solomon stated in the gar discussion,
live food is mainly fish that comes from a pond system where the fish are essentially wild, they are not the same as store-bought feeders.
So when he does feed live, that live food is not raised in a commercial setting, or in an aquarium. Certianly one can raise their own feeders, such as you suggest, but to state
What’s more, and all commercial aspirations aside, I maintain that you can feed a superior live diet to your fish at little to no cost.
does not ring true for every hobbyist out there.
Little to no cost? Short of living in a climate that would allow an outdoor pond, and actually owning such a pond, how exactly would one raise feeders at little to no cost? In my case I would have no choice but to set up another indoor tank, a rather large tank, which would not only cost $$$ to set up, but also to maintain. Then of course we have the little problem of gut loading the feeders in order to provide the predatory species feeding on them a well balanced diet, besides just amino acids & fatty acids. Guess what the vast majority of hobbyists use to gut load their live feeders - that's right, commercial fish food.
So now one has the cost of the system, the cost & time of maintaining such a system (electrical, water, etc), and the cost of the food for those feeders.
Little to no cost?
Maybe for some people that live in the southern USA, for the rest of us it's going to cost $$$, and time. And still, where is the proof that doing so would provide a superior diet, such as you claim?
If as you claim, "it's that simple", then please provide these simple facts to support your claim. The burden of proof is on you amigo, you started this thread, not I.
You state; "you don’t see high growth rates with commercial diets is that they don’t provide a high quality source of proteins and other essential nutrients."
Yet the main "protein" component of all commercial feeds is fish meal, a product that has withstood the test of time in both commercial aquaculture as well as in millions of hobbyists tanks world-wide for several decades.
Are you attempting to tell me that commercial facilities that in some cases spend in excess of 1 million a year in feed, are not seeing "high growth" rates in their trout, salmon, etc, by utilizing commercial feed? Seriously, think about it. In commercial aquaculture geared towards growing fish for human consumption it is all about growth, as the faster the fish grow the sooner those fish can be taken to market.
Using a premium source of protein such as fish meal (that costs a premium $), such as Herring meal, the protein content is typically around 70%, with the protein digestibility value being over 95%, and an amino acid profile that is difficult to beat. And before you suggest that these nutrients are somehow destroyed by the extrusion process - both science & hands on experience has proven that all of these growth promoting amino acids are bio-available to a fish, long after post processing.
"Amino acids, several vitamins, and inorganic nutrients are relatively stable to heat, moisture, and oxidation that occur under normal processing and storage conditions. Some of the vitamins are subject to some loss, however, and should be used in excess of the requirement." (NRC Nutrient Requirements of Fish 1993)
The quality of
any source of protein is dependant on the amino acid profile of those proteins, and the digestibility of those proteins. Add to that premium source of protein, other sources such as krill, shrimp, squid, etc, and you now have an overall "variety" of both amino acids AND fatty acids that have clearly been proven to promote fast growth in fish.
If one then adds a "wide variety" of other raw ingredients that are known to have biological effects beyond just growth promotion, such as immunostimulation, anti-stress, anti-bacterial, anti-fungal, anti-virals, etc - how does this possibly equate to not providing a high quality source of proteins and other essential nutrients, such as you state?
High quality commercial feeds allow for extremely nutrient dense diets, pound for pound FAR greater than any type of feeder fish will supply, especially when one factors in that the body composition of most feeders consist of water. (70-80%)
As previously stated, many juvenile (YOY) predatory species such as Gar, Musky, etc will typically not eat pellets, they MUST be fed live food, period. That does not equate to not being able to raise out healthy Muskie, Gar, or any other piscivore on a pellet food. In fact, many commercial fisheries that work with these fish do in fact feed pellet food once the fish reach a life stage (fingerling) where they will readily accept pellets.
And with some predatory species, they will accept pellets even when in the fry stage.
http://www.nj.gov/dep/fgw/arthackbrd03-2.htm
About 250,000 of these fry survived and swam up in ten days to accept feed. A portion of these swim up fry were placed into fertilized hatchery ponds, while the remainder were kept indoors and started on a mix of brine shrimp and dry feed.
Muskellunge reared at the hatchery in ponds reach 10 inches by September 1 while feeding on fathead minnows. The intensively reared muskellunge fingerlings reach 10 inches by October 15 while feeding on a high protein dry diet. A total of 4,400 of these advanced fingerlings are projected to be stocked this fall into the following waters: Greenwood Lake, Echo Lake Reservoir, Lake Hopatcong, Mountain Lake and Mercer Lake.
While it's impossible to compare water quality between a pond, and an indoor intensive system, the fact remains that even when raising Musky fry, those fry fed pellets in the "intensive" indoor system reached 10 inches only 6 weeks later than those fed fathead minnows in an outdoor pond. Something as simple as water temp could also play a major role in each groups growth rate. All other factors being equal, had the pellet fed fry been fed live food until they reached fingerling size, and then put on a high protein pellet diet, I suspect that the gap in growth rate would have been almost non existent. This is exactly what many commercial producers of Tiger Muskies do, as this hybrid will readily consume pellet feed and can be reared very efficiently in great numbers in a hatchery system, and are only later converted to live feed in order to prepare the fish for life in the wild.
Nutrient composition aside, 6 weeks difference in the growth of a YOY 10" Musky is certainly nothing that any hobbyist is going to get overly worked up over. The difference growth rate would simply boil down to eating more live during this period, than dry.
No surprise there.
Yet with Tiger Musky hybrids, who will readily eat pellet food (probably close to satiation levels) those fish were forecast to also be 10" by Sept 1, exactly the same as the non hybrid Musky that are raised on fathead minnows.
The crew spawned 100,000 eggs of each cross and the expected survival rate to the target size of 10 inches is above 80%. Tiger muskie fry readily accept dry pelleted diets and are therefore raised completely indoors. These 10-inch advanced fingerlings will be stocked by September 1
Well imagine that! So how again is feeding live nutritionally superior?
The bottom line is that overall nutrient value of a feeder fish depends on the fish species, the season, the condition and the diet of the fish. The same could be said about a pellet diet, as clearly not all pellet feed is created equally.
This is precisely why the authors of the paper that you referenced on page 2 of this discussion; ""Nutrition Advisory Group Handbook", Fact Sheet 005", stated the following.
"Wild pinnipeds and cetaceans, as well as piscivorous birds, reptiles, amphibians, and fish, feed on a wide variety of fish species... therefore, the recommended method of feeding most piscivorous animals is to feed at least three, and preferably more, species of fish."
http://www.nagonline.net/Technical Papers/NAGFS00597Fish-JONIFEB24,2002MODIFIED.pdf
If you compare just the major & trace elements found in tables 2 & 3 of that paper, clearly the nutrient values can vary greatly between species. And of course this doesn't even factor in the major vitamins, such as vitamin c which no species of fish can produce on their own, and which must be supplied via the diet.
How much vitamins & trace elements will be contained in a feeder fish will depend entirely on its diet, whether that diet consists of natural food stuffs found in a pond, or whether it comes from a diet of commercial feed.
This is not a clear case of black & white, there are multiple shades of gray that will affect the overall nutrient quantity AND quality of any food stuff, whether that food is a feeder fish, or a pellet.
