ALTERNATIVE TO POLYCHAETES FOR MATURATION
From: Freddrick Poh pohkahhock@mac.com
To: Shrimp News shrimp@yahoogroups.com
Sent: 10 June 2002
QUESTION:
Is there any maturation feed out there, better or
equivalent to replace the polychaetes?
Freddrick Poh
e-mail: pohkahhock@mac.com
***************
Comments 1:
There are some other formulated feed for maturation,
INVE has its formulated feed named BREED-S; it’s oriented to the partial
replacement of the fresh diets (polychaetes, squids, polychaetes, etc) in
the maturation of P. vannamei. This feed is easier to store, you don’t
need to freeze it, as the fresh diets. You can plan your productions
based on a constantly available product with high nutritional profile.
Fabián Jijón
e-mail: fjijon@inve-ecua.com.ec
or inveecua@ecua.net.ec
***************
Comments 2:
Squid and bivalves (mussel, clam, oyster) are
generally the main food items, fed at high daily ratios. Bloodworms (marine
polychaetes Glycera dibranchiata and Americonuphis reseii) and Artemia
biomass (ongrown Artemia) are used for diet supplementation. Bloodworm is
the most expensive ingredient used in hatcheries of the Western atmosphere,
and maturation operators used to feel it to be indispensable for stimulation
of ovarian maturation. Not anymore. It was demonstrated that bloodworms can
be replaced by Artemia biomass or a performing formulated diet easily.
Many authors have successfully used dry artificial broodstock diets at 50%
of the total feeding regime, even when bloodworm and Artemia biomass were
replaced partially or completely in commercial-scale trials, with
BREED-Shrimp (INVE). In commercial maturation facilities the use of
artificial maturation diets is common, but only in low proportions. But also
here, BREED-S proved to be suitable for 50% fresh food replacement and
independence of bloodworms. It is to be expected that the use of bloodworms
is going to become insignificant in the near future.
Roeland Wouters
e-mail: r.wouters@inve.be
***************
Comments 3:
One of the main difficulties related with bloodworms
is that it is a wild catch product, with very variable price according to
the region and season; its price can vary from 2.00- $/lb to 35.00+ $/lb and
of course its quality vary as much.
Species, environmental conditions, life history, harvesting, processing care
& methods vary so much.
Still one of the edge of fresh feeds is their attractability that formulated
diets do not achieve. One may be able to develop the best formulated feed
but if it is not ingested in sufficient quantities or quickly enough by the
shrimp, it is of limited impact on their performance.
When you speak about bloodworms; you have now to split between wild
bloodworms and farmed bloodworms. Quality farmed marine polychaetes from
different sources and different species are now available on the aquaculture
market.
These farmed worms usually are as good as their wild cousins and can even be
much better in nutritional profile, water content (lower), hygiene,
contaminants or biosecurity.
As formulated feeds they are of stable nutritional content, permanent supply
at stable and reasonable prices.
So far the knowledge and processing technology only allow us to consider
frozen bloodworms and I am aware of suppliers and stocks in Europe, the USA
and Australia. One may be close enough to your place for scheduled
shipments.
I am returning from a field visit where I could witness a few interesting
situations where you could see feeding in maturation can be improved:
- pellets (formulated feeds) often lack attractability and will sit in the
tank. After a while the pellet will not be of use to the shrimp.
- fresh feeds like squid, mussels or bloodworms will be chopped into small
peaces to "facilitate" the feeding. Beside the cross-contamination
in preparation of the food, it induces a very high level of leaching and
nutrients get lost in the water. At some level water spoilage can even
become a limiting factor.
- fortunately I could witness some of our customer's shrimp racing to feed
on our worms.
As some know, I am working with Seabait for their aquaculture American
market, they farm "Ragworms" (Sandworms) Nereis virens in the UK
and maintain stocks in the UK and US. We implement a special care in the
Seabait worms produced for aquaculture customers and also work on
improvements.
1- Bacterial load is almost nil and contaminant levels are
as low as it can be.
2- Nutrition is superior to comparable wild worms
3- Individual worm size is tailored so it does not require
to be cut; it can be fed whole as a "portion"
4- Customer service and pricing are competitive
I think our worms are better than wild bloodworms; and I believe so do think
our hatchery customers in the American North & South. Some time ago I
posted a material called "Intensive worms" in the shrimplist
files, you maybe able to review it.
You also can go and review Seabait's website at: www.seabait.com
or contact me offline for more details.
Eric Pinon
e-mail: epinon@ecua.net.ec
***************
Comments 4:
In Brazil nobody uses bloodworms, only Artemia
biomass + squid + some type of artificial dry feed. Has anybody ever proven
that the use of blood worms is absolutely essential?
Francois
Brenta
e-mail: fbrenta@hotmail.com
***************
Comments 5:
I think the answer to your question is no, it's not
essential.
Actually no feed is absolutely essential by itself, especially in the
live/fresh feeds. For instance Artemia is not absolutely essential in shrimp
larviculture; it is just very convenient and much more efficient than using
other live prey or dry diets.
Polychaete / bloodworms are not absolutely essentials for maturation, like
squid; it usually "makes it work better". Past and more recent
research are getting closer to identify the different compounds that these
fresh feeds bring; they can be fatty acids, lipids, hormones, precursors or
maybe just better bio-availability of some nutrients.
As Roeland Wouters (previous emails) has described in recent papers
(Advocate Dec '02); shrimp maturation is a very fast biological process and
the turn-over between each spawn can be as short as 5 days. You certainly
require excellent feeding for the energy and built-up of quality eggs in
such a short time !
According to my experience of the sector, maturation productions with
vannamei can range from 70K naups/female up to 150-170K naups/female, in
parts according to the feeding.
Essential may not be the issue as it is more a question of efficiency; each
hatchery will judge according to its possibilities and production
requirements; for example:
- as you describe in Brazil polychaetes are not used but this is because
their importation is restricted if not prohibited; this is the influence of
a local factor; maybe not because they don't wish to use it.
- we have several shrimp customers - reference in the industry - who did not
use polychaete in their feeding regime before but now use ours. I guess it
does something good to their production.
- in Mexico they have a short and seasonal maturation production (3 month
this year); under this condition, a maturation hatchery will require maximum
output of its facility and may choose the best "efficiency feed"
instead of the most "cost effective" one.
After all, it’s the shrimp and the technical/economical management of the
hatchery that makes the decision.
Sustainable aquaculture is important too: so the reduction of use of wild
origin products.
Land farmed products (agriculture, cattle...) are now at the base of most
food chains and so should it be of aquaculture feeds who still rely strongly
on fish meals, fish oils, artemia cyst, squid or polychaete.... all
fisheries products.
I will acknowledge the work and research of feed manufacturers who work on
reducing the dependency of live and fresh(wild) feeds; specially in
maturation and larviculture.
Seabait raises its worms on a terrestrial (vegetal) based diet, these ugly
crawling things prove to be great food converters and efficient bioreactors.
I only wished to let you know that "non conventional" options are
available to you now.
Eric Pinon
e-mail: epinon@ecua.net.ec
***************
Comments 6:
Aquafauna Bio-Marine has a maturation diet that
closely proximates polychaete nutritional levels. It uses pre-digested
proteins and a high DHA profile cultured algae called Schizochytrium sp. as
a base.
Since the diet is in dry form, the formulation is made with enough binder
for the hatchery to add up to 4% of its own ingredients for further
augmentation. This is handy if a maturation department wanted to use
antibiotics in quarantine or hormones and immune stimulants in the
maturation diet.
I have used the diet at 50% inclusions in maturation tanks with penaeids.
It worked very well and the nauplii output remained as high as with all
natural foods and polychaetes. I might add that at many recirculating
maturation systems where the percentage nightly spawning can reach 13%
consistently a diet of over 50% bloodworms is common. High levels of
bloodworms or Artemia biomass in the maturation diet have always been
required for this high level of productivity. The cost of such a diet
is significant to say nothing of shortages or importation difficulties.
A dry diet is a very handy and cost/effective alternative, but we all could
use more feedback on exactly what inclusion rates are the most productive.
Phil Boeing
e-mail: p.boeing@worldnet.att.net
***************
Comments 7:
Polychaetes have always been a topic of discussion!
They are good indeed from a nutritional point of view, but their replacement
by a more economical/practical/available product was already the top
priority of hatchery managers ten years ago (see survey results published by
Kawahigashi, 1992, in Special Edition on Shrimp Farming, 52-54) and again in
1998 (Kawahigashi, 1998, in Anais do aquicultura Brasil '98, 381-392).
My point is not only that they can be replaced, but also that you can obtain
a better maturation output by replacing them with a good dry diet. That they
can be replaced was already proven back in 1997 in trials performed at
research centers and at a commercial hatchery (see Naessens et al., 1997,
Aquaculture 155, 87-101).
I want to share some results from a feeding trial with wild L. vannamei at
Granjas Marinas in Ecuador. Details will be published this year (Wouters et
al., 2002, Experimental broodstock diets as partial fresh food substitutes
for white shrimp Litopenaeus vannamei B., Aquaculture Nutrition, accepted 8
November 2001). The feeding regime at this hatchery had between 35% and 40%
bloodworms on dry weight base. We compared their standard tanks to those fed
two different dry diets. On dry weight base, 50% of the fresh food was
replaced with dry diet (100% of the bloodworms was replaced). With one of
the dry diets we did not get any decrease in reproductive performance
(spawning, nauplii production, nauplii quality). With the other dry diet we
obtained significant (P<0.05) increases in spawning rate, egg production
per female and spermatophore quality, while other parameters were not
affected. Imagine that, on average, females spawned almost twice as much
eggs than the standard treatment. Ingestion rates of the dry broodstock
diets were assessed in a special designed set-up, and whenever the diet
formulation is good, attractability and intake are excellent. Interesting to
know is that domesticated breeders (breeding programs) thrive even better on
these dry diets then their wild counterparts.
In my opinion, it is only a matter of time (and research) to come up with a
cost-effective dry broodstock diet that can replace all the fresh food at
commercial scale.
Roeland Wouters
e-mail: r.wouters@inve.be
***************
Comments 8:
As for BREED-S, these days an improved version is
being launched. Both the dry compound feed BREED-Shrimp (3 mm pellets) as a
dry premix BREED-Shrimp Concentrate will be available. The latter gives the
opportunity to the maturation operators to mix it with whatever additive
they like (similar to what Phil Boeing mentioned).
Roeland Wouters
e-mail: r.wouters@inve.be