Compensatory Fish Growth

johnnymax

Has anybody tried feeding their fish every 3rd day?

The Southern Regional Aquaculture Center published a report in Febuary 1998
"Restricted Feeding Regimes Increase Production Efficiency in Channel Catfish"
http://aqua.ucdavis.edu/dbweb/outreach/aqua/189FS.PDF

The basis of the study is that some fish when deprived of food for a short period of time will gain weight rapidly when they are finally fed. This is the same thing that happens when humans go off a diet... They put on weight more rapidly, LOL

This phenomenon, known as compensatory growth, can be demonstrated by an increase in both growth rate and efficiency of feed utilization during the refeeding period. Development of feeding regimes that take advantage of compensatory growth will improve the efficiency of fish growth.

Catfish weighing 90 lbs. per 1000 were stosked in two ponds.
The fish in one pond were feed every day all the food they could eat in a 30 minute period.
The fish in the other pond were feed every 3 days all they could eat in a 30 minute period.

After 9 weeks the fish in both tanks weighed the same 1 3/4 oz. (50g).
6 oz. (175g) After 18 fed daily and 21 weeks every third day 6 oz.
10 oz. (275g) After 18 fed daily and 21 weeks every third day
After 27 weeks daily fed fish weighed 12 oz. (350g) and every 3rd day fed fish weighed 10 oz. (280g)

So, if you feed them every third day for the first 9 weeks then feed them reularly after that I wonder if growth will be the same.

KudaPucat

interesting...

TCLynx

So what is the savings in feeding only every 3rd day for the early period? If they were to come out the same after all? Do they actually eat less in total this way?

Bubba

TCLynx wrote:

So what is the savings in feeding only every 3rd day for the early period? If they were to come out the same after all? Do they actually eat less in total this way?

I think the outcome achieved was faster growth rather than saving on feed costs.

johnnymax

from what I understand you save on food. After the fish is hungry for two days, when the fish finally gets to eat the fishes body packs on more weight from the food. The fishes body is in like survival mode and trying to store us for the next famin.

Just like going on a very low cal diet, when you get off and start eating like normal, you gain weight faster from the same amout of food you ate prior to dieting.

Bubba

johnnymax wrote:

from what I understand you save on food. After the fish is hungry for two days, when the fish finally gets to eat the fishes body packs on more weight from the food.

yep rereading it your correct

Quote:

Research has shown that various
animals (including some fish)
temporarily deprived of feed will
grow more rapidly when feeding
is resumed and “catch-up” with
animals that were not deprived of
feed.

The graph of growth shows those fed on the restricted feeding cycle end up a bit bigger but he big saving is on food.
Interesting outcome.

Certainly supports not feeding if you get an ammonia spike in that they will catch up.

TCLynx

So how far does the comparison with people go? When people go on low cal diets and then start eating normal, not only do they pack on more pounds, they pack them on more as fat and their overall metabolism has slowed down.

I would not want my catfish any fattier than it already is.

Chappo

A more sarcastic person may suggest ..... don't feed them at all for a year ,, add a hand full of pellets and remove the 2 pound woppers the next day:)
Agree with TC lynx ..... fat rather than muscle growth would be the result.

A constant supply of quality proteins and minerals/vitamins/ trace elemnts is the best way to promote health and growth. That being said , a lot of people do over-feed their fish and that leads to a lot of waste.

RupertofOZ

An enormous amount of research has been done for most farmed fish... to determine feed compositions ... feed rates... to acheive the best FCR for a species (feed convesion ratio)...

In order to promote the fastest growth and greatest yield... for the minimum cost...

Select your species and research the appropriate feed rates... and feed compositions...

Protein growth is ultimately affected by the limiting amino acid in the feed.... excess is just waste... :wink:

Cyara

Very interesting research article. Thanks JM

I agree that Yo-Yo dieting is known to do that in humans... increase fat ratios in body weight and slow the metabolic rate...but this is actually somethng different...

Quote:

At the end of the experimental period, fish which were restricted from feed for 6 or 9 weeks weighed 90 percent and 86 percent, respectively, as much as those fed to apparent satiation throughout. Feed conversion, dressing yield and body composition values over the duration of the experiment were the same for fish subjected to all feeding regimes.

Quote:

Therefore, if the aquaculturist is unable to feed for a short period because of disease for adverse pond conditions, the fish can compensate for this deprivation if fed to satiation when feeding is resumed. These experiments also suggest that improvements in growth rate and feed efficiency may occur only for a limited time upon refeeding. Therefore, additional study is needed to determine what length of feed deprivation will optimize compensatory gain.

Quote:

Another practical implication of restricted feeding is its effect on fish health. Traditional thought is that fish fed over the winter months are healthier and better able to survive disease outbreaks that occur in the spring. Recent research suggests that this may not always be the case.

Restricted feeding seems to be harmful to the fry but more beneficial to the 2 year old fish. I know that fasting at certain times is extremely beneficial to health in adult humans. A local commercial enterprise places his fish in "stew ponds" before slaughter... fresh water and zero feeding for a couple of weeks before slaughter. This cleanses and improves flavour he says.

If linked with some other research I have read about it expands the possible benefits.........

Quote:

Research - Fasting and Calorie Reduction Detoxifies the Body

But the new study by Mark P. Mattson and colleagues at the National Institute on Aging found equal benefits for mice that ate only every other day, but didn’t cut total calories because they ate twice as much on days they weren’t fasting.

Mattson said a study is in the planning stages to compare the health of a group of people fed the normal three meals a day with a similar group, eating the same diet and amount of food, but consuming it within four hours and then fasting for 20 hours before eating again....

.... Mattson said an earlier study found that mice that fasted every other day had extended lifespans and the new experiment found the mice also did better in factors involved in diabetes and nerve damage in the brain similar to Alzheimer’s disease.

“We think what happens is going without food imposes a mild stress on cells and cells respond by increasing their ability to cope with more severe stress,” Mattson said. “It’s sort of analogous to physical effects of exercise on muscle cells.”

He said the researchers think this stress occurs throughout the body, and that may be the reason fasting seems to increase lifespan and the animals become more resistant to the diseases of aging.

The dieting mice consumed 40% less food than mice eating normally and lost nearly half their body weight (49 percent) in the experiment, while the fasting mice weighed only a little less than mice eating normally....

...Fasting Increases Resistance to Toxins

At the end of the experiment all three groups of mice were injected with a toxin that damages cells in the part of the brain called the hippocampus. It’s cell damage there that that is involved in Alzheimer’s in humans.

When the mouse brains were later analyzed the scientists found that the brains of the fasting mice were more resistant to damage by the toxin than the brains of either dieting mice or those eating normally.

By Tom Coghill of Fasting.ws
http://www.fasting.ws/juice-fasting/fas ... ch-on-mice

Chappo

Cyara , I agree an occasional fasting period is indeed good for adult humans ,, but we are not being grown for food ( not yet anyway,,think Soilent green).
2 year old fish,..... well I have no experience there , all the fish i grow to eat are Adult size within 6 - 7 months and a great part of achieving that growth is calculated feeding regimes following decades of research. I speak here only on Tilapia , as they are the only fish i can claim extended experirence with.But if/when i grow other speciaes i will certainly be following the recommendations of results concluded from decades of experience and experimentation.

Don't get me wrong , I hope this method does work and can be replicated hundreds of times to proove it's worth. Sure would save my workers in Thailand waking up at 5am for the first Tilapia feeding. I do recall one experiment that suggested nil feed one day per week but I read that years ago and cannot recall where.

I would also guess results would vary greatly between fish species,,,

johnnymax

I agree about fat build up, but when you stop feeding they will use the fat to grow. That is the purpose of the body storing fat... to use later. So, I think the fat thing is not an issue.

Cyara

Yes. I agree Chappo. Is just experimental at this stage but of great interest to me. They were using catfish hence the 2 years of age spoken of I would think. Tilapia mature much faster and this might make it more suitable for this type of thing. Might. Lots still to learn....

It is the benefits of IF (Intermittent Fasting) that are being so widely applauded that has tweaked my interest. If it is beneficial to mice and men it is most probably beneficial to fish. The healthier the fish the better it is as a food product. Definitely less medication needed for a start on a commercial level. I am happy to grow out longer than normal commercial pressures allow anyway. It is a hobby for now.

Here is one anecdotal blog on the subject that first got me interested in IF. http://lifespotlight.com/health/2008/03 ... ess-story/ There are many scientific studies showing benefits but this is easy reading as a starter should anyone be interested

Do you use "stew ponds" before slaughter? The guy I spoke of does this with tilapia.

Chappo

Cyara , We have not needed to use stew ponds ,, well we call them purging tanks , for our pellet fed Tilapia . But we did do a few catfish grow outs and they definately benefited in flavour from being purged for several days.AHH just to clarify ,, Asia catfish not the American type. I also blieve Silver Perch here in Autralia are purged before sale and also Barramundi
( Sea Bass) SO i guess it varies from species to species.

Cyara

Interesting. Thanks Chappo.

I had another thought.... if you are using urea to create algae bloom for the tilapia do you still feed commercial pellets at regular intervals each day? You mentioned your staff waking up at 5am for the first Tilapia feeding.

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Compensatory Fish Growth

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