This is from one of the KHA's on the KHA board. Unfortunately it came to me
in Adobe, so if anyone would like the whole thing, let me know
and I'll E it to you, as there are a whole bunch of
threaded messages. This was on the NI board in 2004 so hopefully a formal
report will be coming out soon.

Even though it isn't about catfish & trout chow, it does bring up some
interesting points regarding feeding/overfeeding/improper feeding.
~ jan

Fatty Liver /Metabolic Syndrome Disease in Koi -- Research
Posted by thom blischok on 11/26/2004, 6:41 am

Fellow NI'ers,
We have just completed a one year study effort regarding the feeding of koi
and have some rather interesting results.
The hypothesis we were trying to validate is one I've personally felt was
unanswered in all for the literature I've read to date -- and that
hypothesis centered on the idea of "growing koi" at faster metabolically
normal rates -- that is "bulking up" to grow them fast and big. We will be
publishing the study in a couple of months and I thought that I'd provide
some insights that might be interesting for us all to reflect on as we
determine the rate of growth that we create as a result of our feeding
regimen.

First, lets talk about the groups of koi we used in the study. Each group
had twenty five koi randomly selected -- these koi were pulled form my mud
ponds (three year olds) and placed into large 100,000 gallon flow through
cement ponds. Group A was fed amounts based on normal body weights
calculated at the time of placing the koi into the ponds and recalculated
each month. Group B was fed five times normal rates with the idea of
"bulking them up" as fast as possible (they were fed five times per day
versus two times per day for Group A).

Group A was forced to forage for much of their food and Group B seemed to
be satisfied from an appetite perspective almost always.
Water temps were in the 75 degree range and water quality was optimal
throughout the entire test period.

To summarize a couple of results, Group B grew at least 50% more than Group
A -- typically exhibited by a huge underbelly (this if course was supported
by fish deemed to have the proper genetics to grow to large sizes). Group A
was quite active throughout the day foraging for food while group B was
quite sedentary waiting to be fed.

We did quarterly blood tests on all glucose, cholesterol, triglycerides,
amylase, and lipase. We fed a food base that was 45% protein (basically a
high growth diet) with 10% fat, 15% carbohydrates, 10% fiber, 9% ash, 1%
vitamins, and 10% moisture. We calculated the total energy for this diet at
approximately 350 kcal/100 grams of food.

As we began to come to the end of the study we wanted to understand the
effect of "Bulking up" and we learned a lot (of which I'll share some
initial findings that will be published later). First, upon doing
necropsies on several koi from both groups we clearly saw very distinct
differences in blood chemistry (the blood samples were taken before we
euthanized the koi).

The Group B fish had serum glucose levels above 160mg/dl (norms of 30 -
120mg/dl) -- in some cases approaching 180 mg/dl; cholesterol was in Group
B over 490 mg/dl (norms 200mg - 400mg/dl); and Triglycerides -- some over
600 (approaching 700) mg/dl,(norms 100mg - 500mg/dl).

As we got into the body cavity we saw significant and numerous adipose
deposits in the gut areas -- several quite hard -- almost calcified. As we
began to look at the organs we saw fat deposits in the liver as well as
some nephrotoxcicity in the kidneys (also in the liver). We saw a
build up of fat around the heart and a general observation that the
internal organs were not getting quite the same blood supply as the Group A
fish -- the coloration of the Group B fish was slightly more of a dullish
red/brown versus a shiny more red appearance. From my perspective the
coloration differences directly reflects organ optimal health.

As part of the research effort we basically diagnosed the koi in Group B as
having a human disease -- we call it metabolic syndrome -- that is -- the
blood sugars were quite high from overfeeding, cholesterol was elevated,
triglycerides were abnormal, lots of fat deposits especially in the gut
areas, and finally organ function was clearly deteriorated.
The reason we embarked upon this effort was primarily driven by the old age
debate of "should we grow koi as fast as we can (like the food fish farmers
do) or should we be more conservative in our approach.
As many of you know in our ponds we have worked hard to follow the more
conservative approach and have been satisfied with the results to date.
So without releasing all of our findings yet (we still have lots of data to
validate) I thought I'd give some "food for thought" to this board on
feeding habits and the actual result of overfeeding (in THIS STUDY).
Thoughts from a simple koi keeper.....
thom....
----
Posted by Brett on 11/26/2004, 11:57 pm, in reply to " Fatty Liver
/Metabolic Syndrome Disease in Koi -- Research "

Was either group more mature and the females more gravid?
Which group might offer better spawning success? I find these results
interesting. Something seen by local alligator breeders is that "well fed"
and lazy gators tend to have poor reproductive success in semi-captivity
compared to better exercised and less regularly fed gators.
The goals of bringing a koi into show form, that of health and longevity,
and preparing them for reproductive success (not just spawning but also
gamete quality) might require differing approaches, especially with respect
to diet.

In this study, what is the ultimate goal with respect to desired outcome?
Enlightening study.
Brett

effect of two protocols on gonad development?
Posted by thom blischok on 11/27/2004, 1:13 am, in reply to "effect of two
protocols on gonad development?"

Brett,
We had a combination of males and females and did not even consider the
spawning effect.

We simply pulled out of the pond some of our spawn from previous years that
were now three year olds.

Can't answer the question which group might have better spawning success
although from what I saw during necropsy, my guess would be the Group which
was fed a more conservative diet. My guess is that the "fat group" would
not spawned as well. Lots and lots of fat buildup in the stomach cavity.
Interesting on the alligators.

The desired outcome was quite simple. I wanted to know the actual
scientific effect of feeding a long term high growth diet. In my own mind
I've always questioned the rationale of "fattening them up" for the show --
that is growing them big -- fast.

In the case of the koi in my ponds, my feeding regimen has centered on slow
consistent growth with approximately 60% of the daily food content coming
from foraging the walls and bottom of the pond.

From the NI perspective, I thought the study might spark a thought or two
about the massive feeding of food (any type) and its potential long term
effect on koi health.

As I have continued to explore koi shows, one of the awards I'd sure like
to see is an award based on longevity and health. From my perspective far
too much emphasis is on the "beauty queen" part of the show and not enough
on koi that have been grown with great husbandry techniques.
Might be an interesting kind of recognition for a koi keeper -- in my
humble opinion -- probably one of the most important recognitions that a
koi keeper can get is to be recognized as a keeper of the bloodline over
time -- not just the owner of a koi for the moment.

What I personally continue to find ever challenging is keeping great koi
looking great in "CEMENT CLOSED LOOP PONDS". I now know that this goal is
and will continue to be something to strive for on a regular basis.
thom......