Looking for supplier

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Dallas,

I appreciate your feedback and I am sorry you have had poor results with
dry food from other companies. I can't give you any data on the 12 month
shelf life because I haven't tested the food that long. We typically keep
our dry baby food (Biokyowa in this case) in the -80 freezer. We only
pull out a small amount at a time which we keep in a 4 degree fridge in a
50ml polypropylene tube. We used an aliquot of dry food kept at 4 degrees
for up to 8 months and did not see a decrease in survivability.

As for testing, AHAB sent me a sample of their dried food (Larval diet).
I took one large clutch of embryos (an outcross of a mutant line) and
split the embryo into 6 tanks. 2 tanks had 80 embryos (many), 2 tanks had
40 embryos (medium), 2 tanks had 20 embryos (few).

I fed one set (many, medium, few) with Biokyowa per our standard protocol,
and one set with the Larval diet.

In both cases, we had approximately 80% survive in the tanks with 20
embryos, 90% survive in the tanks with 40 embryos, and 70% survive in the
tanks with 80 embryos. And I am sure other people would have different
results due to many parameters, this is just what I got with my current
setup.

As for 80+ embryos in a baby tube, we typically try to put between 20-40
in a tank (AHAB tanks, baby tube setup) in general. I just wanted to see
if too many embryos impacted survivability under our conditions.

I haven't tried feeding our larvae artemia at 3 days and for all I know,
they could eat it. But in general, our protocol works and we get good
healthy fish in a reasonable time frame so I am satisfied. If I couldn't
raise fish and was having trouble with egg laying, maybe I would consider
doing a live diet for larvae, but at the moment I can't convince myself
that the hassle and cost would be worth it in my case. I am also not
ready to switch to "cow manure" and let nature take it's course. 8)


All I was trying to get across to those who also like dry diets for larvae
is that AHAB's product worked well enough for me.

- Becky

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Rebecca Burdine, Ph.D.
Assistant Professor
Department of Molecular Biology
Washington Road
Princeton University
Princeton, NJ 08544

Ph (609) 258-7515
Fax (609) 258-6730
e-mail: [Only registered users see links. ]


-----Original Message-----
From: [Only registered users see links. ]
[mailtowner-zbrafish@hgmp.mrc.ac.uk]On Behalf Of ""
Sent: Saturday, October 30, 2004 5:18 AM
To: [Only registered users see links. ]
Subject: Re: Looking for supplier


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Rebecca,

You should note from the label that the "Larval Diet" product contains
fish oil and mineral pre-mixes. The fish oil contains omega-3
polly-unsaturated fatty acids which will auto-oxidize in air into some
really nasty products. The mineral mixes work as catalysts for this
reaction. I am not sure you can put in enough preservatives to hold the
diet together for 12 mo. Normal preservative concentrations only result
in 3 mo diet stability with these ingredients. Oxidation of vitamin C is
another problem in many diets (required nutrient for almost all fish
species -- probably also for zebrafish?).

You also have the leaching problem with dry diets, where water soluble
nutrients leave the diet on a time scale related to t=K D^2 (for a 1 mm
particle, the time scale in on the order of 1 minute)- (C= Co e (-kt/x^2)
type function for long times). For a 100µ type diet, the kinetics for
diffusion of water soluble components is only a second or so from the time
the particle is wetted.

Note that Aquatic Habitats is a subsidiary of Aquatic Ecosystems, which is
a major supplier to aquaculture. Note that "Larval Diet" has not taken
over the several hundred million dollar market for commercial larval
diets. I have never seen any real science or testing relative to this
product and Aquatic Ecosystems doesn't have internal capacity to do any
real diet testing.


Keep the larval density low enough and you can feed them cow manure and
let a natural microbiological ecology do the rest. Putting stripped bass
larva in a pond at about 20-50 larva/m2 of surface area in a pond with
manure is micro-biologically similar to 5 zebra larva in a 2.7 L AH tank
being fed any dry diet.

Under optimal nutritional conditions, it should only take 3 days of good
feed for a larva to be large enough to eat artemia, not 10 days.

Dallas
--
Dallas E. Weaver, Ph.D.
Scientific Hatcheries
5542 Engineer Dr.
Huntington Beach, Ca 92649
[Only registered users see links. ]
[Only registered users see links. ]



PS: I became sensitive to this age of diet question when I obtained some
old diet from Puerna that cost me hundreds of thousands of dollars before
I figured out what happened (they don't have public age dates on their
products)-- distributor not rotating their product properly. A dry diet
without a date shouldn't be used. It usually doesn't kill the fish, but
you just bounce from one problem to another ranging from low fecundity,
low fertility, poor survival, slow growth, poor food conversion (FCR),
disease susceptibility, etc.




in article clu1d6$rdd$[Only registered users see links. ].ac.uk, Burdine, Rebecca at
[Only registered users see links. ] wrote on 10/29/04 11:16 AM:

food called "Larval Diet". The ordering information is #LD100 for a
500gram can for $20.25. It has a 12 month shelf life.
essentially identical success rates for raising fish. We will likely
switch to this once we run out of Biokyowa.
animal proteins, vegetable protein, yeast, vegetable starches, fish and
vegetable oils, vitamin and mineral pre-mixes, pigments, antioxidants, and
biodegradable binders."
starting on day 5 to day 7. We switch to artemia on day 15. We
typically have 80-90% survival rates, but this depends on the line of
fish. A good healthy wildtype strain will give us close to 100%
survivability.
cleaning out uneaten food every feeding to keep the water quality high.
you our experience with the food so far.
for 6 to 9 months when most of the high quality commercial aquaculture
diets seem to be 3 months shelf life. Notice, they also recommend
rotifers for the first 10 days.
where the NIH and others are spending a lot of money on research and there
is no basic dietary information. We know far more about the dietary
requirements of all aquaculture species and most "want to be" aquaculture
species.
won't impact the research results. However, we do know that diet does
impact fecundity, fertility and larva viability on zebra fish. just like
other species of fish/shrimp.
requirements and not optimal, just workable. I do know that diets age
will impact fertility and that leutine pigment in the diet will make the
males easier to sex (yellow fins).
relevant things you come up with is some work on Boron and the work by
Landon on larval diets. This is relative to journals devoted to
fish/shrimp nutrition for all other species.
nutritional research on this animal. There are a lot of good
aquaculture nutritional researchers who have worked out the details on
other species that could do the job, but they are part of aquaculture
research not normal NIH researchers.
[Only registered users see links. ] wrote on 10/25/04 5:45 PM:
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product. You will need

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