Mike, it has been proven in labs, by experts in this field, that excessive dietary lipids causes fatty live disease in fish. I have been posting about this exact subject for many years, and I have read many of these scientific papers, researchers aren't making this stuff up. This is not me saying that you can't, or shouldn't feed meat to a fish, this is me saying that you used a rather poor example in beef heart.
I've been saying this for the past 20 years, and many of those who work in the field of aquatics agree - one of the most common causes of death in captive fish is related to excessive fat deposits in and around the organs. Excess fat ends up stored in various tissues, specifically the liver. Over time this can lead to the degeneration of the liver, which is more commonly referred to as "Fatty Liver Disease". Years ago I read an article which included some info from a fish parasitologist at a Canadian University. He was involved with performing autopsies on dead fish at public aquaria and the single most common cause of death he's seen since he started to do the autopsies was "fatty liver disease". Ruth Francis Floyd from the U of Florida has stated the same.
I first posted the following approx. 15-20 yrs ago on a cichlid forum where I was a mod, this quote coming from 8 yrs ago on MFK.
I've been saying this for the past 20 years, and many of those who work in the field of aquatics agree - one of the most common causes of death in captive fish is related to excessive fat deposits in and around the organs. Excess fat ends up stored in various tissues, specifically the liver. Over time this can lead to the degeneration of the liver, which is more commonly referred to as "Fatty Liver Disease". Years ago I read an article which included some info from a fish parasitologist at a Canadian University. He was involved with performing autopsies on dead fish at public aquaria and the single most common cause of death he's seen since he started to do the autopsies was "fatty liver disease". Ruth Francis Floyd from the U of Florida has stated the same.
I first posted the following approx. 15-20 yrs ago on a cichlid forum where I was a mod, this quote coming from 8 yrs ago on MFK.
This is exactly the type of food that you do NOT want to be feeding a flowerhorn.
Part of the problem with FH keepers (and lots of MFK members in general) is they all want to see MAJOR growth in their monster fish, in as little time as possible. While there are many ways to achieve that goal, often times all it results in is a large obese fish, that will eventually die prematurely due to fatty liver, etc. Of course if/when that happens, most hobbyists won't have a necropsy performed to understand why their pet fish suddenly died, they will simply go out and buy another one. (sudden death syndrome anyone?)
IMO this hobby is all about patience, and measuring success in years, not weeks, or months. When it comes to feeding fish, many hobbyists make things much more complicated than they need to be.
I recently posted the following in another thread, and it might be worth repeating here. While the fish used in this study were not FH, they were cichlids, one being a carnivorous species, the other an omnivore. The same info would apply to any & all FH strains.
Feeding high protein, and especially high fat levels to adult cichlids can be a dangerous proposition, even with carnivorous species. (which flowerhorn are not)
The following exerts come from a study overseen by Dr. Ruth-Francis Floyd, a DVM, MS, and a professor at the U of FL that specializes in fish nutrition & health.
The TP diet was comprised of 52% crude protein, and 17% crude fat. The FF diet consisted of 47% crude protein, and 7% crude fat.
"The lipid-rich TP diet may be suitable for commercial production of juvenile African cichlids up to 12 weeks of age, but prolonged feeding may result in excess lipid deposition and necrosis of the liver. Feeds like the FF diet, which produced slower growth but lower lipid deposition in livers, may be more suitable as a maintenance diet for cichlids in the home aquarium.""Fatty infiltration of the liver has also been designated "the most common metabolic disturbance and most frequent cause of death in aquarium fish""With prolonged feeding of a high-energy, lipid rich diet, degenerative changes of the liver and death can occur unless the diet is corrected."
Now imagine what happens to the liver of an adult CA cichlid/flowerhorn (with much lower metabolisms) when fed diets that contain excessive amounts of lipids. (fat)
The juvie H. ahli (s. fryeri) used in this study faired much better being a carnivore, but it still showed a lipid accumulation in the hepatocytes. (<50%) The P. socolofi had extensive lipid accumulation when fed this TP diet.
This study came about after some cichlid farms in south FL suffered from some large mortalities in both 1998 & 1999. When the dead fish were examined they showed fatty infiltration of the liver, heavy vacuolation, and severe necrosis of the liver, pancreas, and spleen.
It was suggested to the farms that they replace ther feeds with one that had a lower lipid content (less than 10%) and supplement the feed with a vitamin premix. Clinical signs in the affected farms were resolved after implementation of these recommendations.
Fat that is not entirely utilized by a fish as an immediate energy source (which is the main role of fat in a fishes diet) does not equate to all of the excess going directly to growth of a nuchal hump. Most of that excess fat will be deposited in & around the fishes organs, which long term will degrade the health of the fish, and in many cases cause premature death. When I read about the numerous cases of SDS (sudden & unexplained death) in FH I often wonder how many of these cases involved overfeeding, and/or an excess of lipids (fat) in the diet. Unfortunately the vast majority of hobbyists do not have a necropsy performed when their prized fish suddenly dies prematurely, they simply replace it with another fish.
I've been promoting sound husbandry practices (such as limiting a cichlids fat intake) for many years, long before any of the specialty FH foods were on the market. None of this comes as news to me.
While I agree that there is no need to pay some of the ridiculous prices for FH specialty foods, if all one is wanting is a cheap low cost generic farm feed (which IMO is exactly what this is) you would be FAR better off in buying direct from a feed mill, or your local hardware store. It will work out to approx $1 a pound, but will come with the same problems as the food listed by Bud. (excess protein, excess crude fat)
HTH