QUESTION:
I am looking for information on using the spray-dried algae,
(Schizochytrium sp.) otherwise known as algamac-2000 as an enrichment for Artemia and rotifers.
I have the paper by Barclay and Zeller, 1996 but this looks at
enriching very small volumes of live food. I am interested in results
on a commercial scale level. Since enriching live food is affected by
such things as temperature and oxygen levels the results for enriching
in one liter tanks will likely be different than that in 1000 liter
tanks. We will be harvesting 100-200 million Artemia a day so I would appreciate some response from actual buyers and users
of the product.
I am very interested in any comparisons made with oil emulsion
products and other enrichments.
How do the fatty acid levels compare, any differences in growth rate,
survival, stress resistance...etc?
Dena Wiseman [SMTP:dena@morgan.ucs.mun.ca]
Sent: March 05, 1997
To: Multiple recipients of list BRINE-L
***************
COMMENTS 7:
I would like to inform you about some comparisons using INVE
enrichment products that we are aware of. You are very right in that
enrichment data obtained in small scale should be confirmed in large
scale. In this regard, the data presented here are run in "large lab
scale" (rotifer enrichment in 90 l, Artemia enrichment in 10 l
tanks).
1. Enrichment of rotifers
We organized an experiment to run the following products according to the instructions for use as 8 h enrichment at a 90 l scale (400
rotifers per ml).
a. ALGAMAC2000: 100 mg/l at t0 and 100 mg/l at t=4h
b. DHA PROTEIN SELCO: 125 mg/l at t0 and 125 mg/l at t=4h
c. DHA SELCO: 50 mg/l at t0 and 50 mg/l at t=4h
(b and c are, respectively, a protein and lipid based enrichment
product of INVE AQUACULTURE N.V./S.A.)
Enrichment results (mg/g dry weight):
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Prior to enrichment : EPA 4.1; DHA 2.1; sum n-3 HUFA 9.1; DHA/EPA ratio 0.5
a : EPA 5.1; DHA 31.3; sum n-3 HUFA 40.0; DHA/EPA ratio 6.1
b : EPA 10.1; DHA 17.0; sum n-3 HUFA 35.0; DHA/EPA ratio 1.7
c : EPA 12.5; DHA 28.9; sum n-3 HUFA 48.3; DHA/EPA ratio 2.3
starved control : EPA 3.4; DHA 1.6; sum n-3 HUFA 7.8; DHA/EPA ratio 0.5
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It seems that the three diets satisfy the requirements for high DHA
enrichment of rotifers (reaching > 3.5% of sum n-3 HUFA with ratio
DHA/EPA >1.5). It is not clear at the moment if a further increase of
the DHA/EPA ratio far beyond 2 (level often occurring in copepod polar lipids) is effective in larval fish.
2. Artemia enrichment
Shields and Bell (1995 - Larvi 95 EAS special publication 24:188-191) reported sum n-3 HUFA of 35.4 (area%, no mg/g data available) and a ratio of 1.2 in Artemia fed Schizochytrium (Kelco). A ratio of 1.4 can be obtained through routine enrichment of brine shrimp using DC DHA SELCO (giving up to 62 mg/g dry weight sum n-3 HUFA with DHA/EPA 1.4). Using experimental emulsions, even higher DHA/EPA ratios could be obtained in Artemia (eg. DHA/EPA 2, Evjemo et al., in press- presented at Larvi 95).
I hope this information is useful for you and remain interested to
follow this discussion.
Dr. Peter Coutteau
INVE TECHNOLOGIES N.V.
Oeverstraat 7, B-9200 Baasrode, Belgium
Tel. 32-52-331320 Fax. 32-52-334531 @mail:p.coutteau@INVE.be
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