High cost of fishmeal, the volatility in the price of agricultural commodities and the stagnant price of aquaculture products are constraining aquafeed manufacturers to pay very close attention to the cost-effectiveness of their feeds.

1. September | October 2011
Feature title: Challenges associated with carrying out a meta-analysis of
essential amino acid requirements of fish
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2. F: Amino acid
Challenges associated with carrying out a meta-analysis
of essential amino acid requirements of fish
by Guillaume Salze*, Margaret Quinton and Dominique P. Bureau, UG/OMNR Fish Nutrition Research Laboratory,
Department of Animal and Poultry Science, University of Guelph, Guelph, ON, Canada, N1G 2W1
Email: gsalze@uoguelph.ca
H
igh cost of fishmeal, the fish and penaeid shrimp over the past and feed efficiency, as well as differences in
volatility in the price of 50 years and the body of knowledge on the mathematical and statistical approaches
agricultural commodities EAA requirements of aquaculture species is used to analyse data, these result in high
and the stagnant price of continuously expanding. variability in estimates of EAA requirements.
aquaculture products are constraining One of the problems resides in keeping Understanding the reasons underpinning
aquafeed manufacturers to pay very up with progress and developing a whole- this great inconsistency is important for
close attention to the cost-effective- some understanding of the ‘state-of-the-art’. developing more reliable and practical esti-
ness of their feeds. The great diversity of methodological mates of EAA requirement of aquaculture
approaches used and animal species and species.
Nutritionists are required to formulate ingredients studied as well as the multitude All these issues point toward a need
to lower or narrower essential nutrient of opinions with regards to optimal levels for the systematic integration and analysis
specifications in order to minimise feed and modes of expression of EAA require- of information from the large number
cost. At the same time, these feeds must ments limits the ability of manufacturers to of studies that have been published so
sustain high growth, feed efficiency, health meaningfully improve the cost-effectiveness far on EAA requirements of aquaculture
and product quality of the animals at the of feeds and/or adapt formulations to an species. Statistical meta-analysis offers a
farm. ever changing commodities market. mean to realize by integrating and standard-
Nutritionists also are relying on an A number of scientific reviews and izing information and allowing meaningful
increasingly diverse portfolio of ‘economi- publications have attempted to summarise comparisons.
Amino Acids
cal’ protein sources, with different amino the body of knowledge on EAA nutrition The goal of this project was to carry
acid profiles. and requirements of aquaculture species out a meta-analysis of EAA requirement of
Thus, formulating cost-effective aqua- (Wilson, 1989; NRC, 1993; Cowey, 1994; Lall fish through the construction of a dataset
feeds requires increasingly precise infor- and Anderson, 2005; Bureau and Encarnação, gathering all available data on EAA require-
Choosing the right nutrients for your Aquafeed
mation on essential amino acid (EAA) 2006; Hernandez-Llamas, 2009; NRC, 2011), ments of teleost fish.
requirements of aquaculture species. and some concluded that the state-of-the- Headquarters
art on EAA nutrition of aquaculture species
Evonik Degussa GmbH Our amino acids help to
Health & Nutrition
Dynamic field of research is still quite shallow. feed additives • replace costly and scarce raw materials
Aquaculture nutrition is a very dynamic The choice of the mode of expression Rodenbacher Chaussee 4 • improve protein balance and production efficiency
63457 Hanau-Wolfgang, Germany
field of research. A very large (percent dry diet, percent crude protein, phone +49 6181 59-2256 • reduce environmental pollution
number of stud- g/kJ digestible energy, ideal protein, etc.) fax +49 6181 59-6734
ies have been of EAA requirement is a matter of much
Europe & Middle East Africa +49 6181 59-6766 feed-additives@evonik.com | www.aminoacidsandmore.com
conducted debate, and reflects the conflicting assump- Latin America +49 6181 59-6761
on EAA tions authors make when considering what North America +1 678 797-4300
nutri- affects the requirements or not (Bureau and Asia North +86 10 85 27-6400
Asia South +65 6890-6861
tion of Encarnação, 2006; Bureau, 2008).
teleost Together with methodological issues
(notably limita-
Figure 1: Diagram illustrating tions of the
the screening of studies, from experimental
the total number found to the design used), Figure 2: representation of EAA
number of suitable studies that across the dataset
constituted our working data set the variability in
achieved growth
28 | InternatIOnal AquAFeed | September-October 2011

3. F: Amino acid EDITOR’S DESK the accu- poor growth performance achieved during Simple steps can
F: Aqua News
Amino acid
Nutrición Acuícola, Universidad Autónoma de
racy of the the trial. Aquaculture centre welcomes CFP toreforms
be taken improve Nuevo León, Monterrey, Nuevo León, Mexico,
WELCOME TO INTERNATIONAL AQUAFEED MAGAZINE
non-linear The large number of species studied the quality and pp. 29-54.
T
regres- and the large number of EAA resulted in he new Astec Aquaculture sented by Maria Damanaki, relevance of futurethe need for a in the sector, we ver y much
ously highlighted
Bureau, D.P., 2008. Toward a better definition
s i o n s a very fragmented dataset (see Figures coordinated approach to support welcome the EU’s intention to
Business & Science Centre Commissioner for Maritime studies and allow
of essential amino acid requirements of fish,
analyses. 2 and 3). located on Nor th East Affair s and Fisheries, Astec us the develop moreof this dynamic remove administrative and legis-
to development International Aquafeed. Perendale Publishers Ltd,
Studies For example, the dataset only includes England’s Northumberland coast- welcomes the EU’s recognition precise estimatebut fragmented industry, 14-17.
pp.
so we lative barriers to trade.”
had to four studies on phenylalanine require- line, is a purpose-built facility, of the importance of developing of are par ticularly suppor tive of
EAA require- Mr Haddrick adds, “Astec shares
report ments, which were all conducted on dif- which provides a unique and sup- ecologically viable aquaculture as ments.EU’s plans to establish a new 1994. Amino acidof Commissioner
the Experiments Cowey, C.B., the views requirements
informa- ferent species. Great differences in the portive environment for all types Aquaculture Advisor y Council Damanaki presentthere is great
should not ideally of fish: a critical appraisal of that values.
tion on body weight of fish used (<1g to more of aquaculture related business to give than and Aquaculture 124, 1-11.
use fewer advice six guidance on potential within the aquaculture
w a t e r than 600g) introduce some challenges for and research activities. experimental diets, sector.
industry-related issues.”Lall, S.P., Anderson, S., 2005. Amino acid nutrition
t e m - standardisation of data. It has a specific focus on helping and The repor tsuf- states that Dietary requirements and to seeing
report also of salmonids: “We look forward
perature , Almost half of the studies did not report fledgling 5: Estimatedto become
Figure enterprises arginine requirements for for aqua- how the framework develops
ficientbetter framework bioavailability. Cahiers Options Méditerranéennes
“a information
Figure 3: representation of species across the datase
experiment information on carcass composition. established andaccording to as mode of expression
rainbow trout grow, and the 63, 73-90.
diet will increase production and strongly suggest the EU grasp
on culture composi-
duration, diet Protein gain (retention), an important such, provides a unique combi- tion, growthof per-
and supply seafood in the EU, this opportunity to ensure aqua-
Hernandez-Llamas, A., 2009. Conventional and
The main objectives of this effort were composition (dry-matter basis), initial response variable for EAA requirements, 14nation of ‘plug-in for arginine requirement
and 23 percent and go’ facilities formances and husbandry information. imported culture plays an integral part in
reduce dependence onalternative dose-response models to estimate
identifying factors that may affect estimates and final individual body weight, and feed could only be computed for a limited of and specialist business suppor t
rainbow trout). The BLM has now been clearly dem- in coastal developing a more sustainable
fish and boost growth nutrient requirements of aquaculture species.
of requirement, highlighting the shortcom- intake. Screening of the studies with number of studies. services.
This shows that much remains to be and rural areas.”
onstrated to underestimates require- Aquaculture 292, 207-213. to fisheries manage-
approach
ings in the existing body of knowledge, and these selection criteria yielded a final Finally, only 16 percent of the studies in done to has a very unique offering
Astec reconcile the existing data and By 2014, Member States will ment.”
ments, and thus should be avoided.
NRC, 1993. Nutrient Requirements of Fish.
providing guidelines for future research. dataset comprised 109 studies, which the working data set included some evalua- determine factors marine scientists
that appeals to underpinning variability. Instead, the QM or draft national strategic plans to
BQM offer a
National Acad. Press, Washington, DC.
covered all 10 EAA in 28 teleost species tion of protein digestibility. and industry alike – a year round points
Nevertheless, several valuable remove administrative barriers More inforMation:
better balance between accuracy and
Building a working dataset (see Figure 1). Consideration of digestibility would supply of near tropical temper-
arose from the data standardisation. practicality (that is, parsimony and environmental, social Nutrient requirements of fish
and uphold ease NRC, 2011. Astec
A comprehensive search of papers on greatly strengthen and refine our under- ature, flow-throughmodels was impact-
The accuracy of the seawater, of fit). and economic standards for the TheLyne Sands, Woodhorn Press,
and shrimp. National Academies
EAA nutrition of commercially relevant A fragmented & diluted standing of EAA requirements in fish by edenablingshape of the curveaquatic meant
by the a wide range of they are farmed-fish industr adds the Northumberland
Most importantly, studies should be y, Washington, D.C., 360 pp.
NE63 9NW
teleost species (for example, salmonidae, body of knowledge taking account of some of the variability to plants and animals to be culti-based onof itsdesigned so results fit areport. ‘diminish-
fit. Since all of these models are part proposals to manage clear Wilson, R.P., 1989. Protein and amino acid
United Kingdom
cychlidae, cyprinidae) published in peer- It is striking that less than half of the 249 due to bioavailability of EAA in different vated there. fish stocks.ing return’ pattern. The “As the dietary aquaculture ofTel: +44 1670 852771nutrition. In:
the law of diminishing returns, they attempt graded UK’s first requirements fishes. Progress in fish
reviewed journals and other technical pub- original studies could be considered for the ingredients. to fit curves shaped as those illustrated in Haddrick, of the test EAAbusiness incubator, with a focus Email: info@astecaquaculture.com
Further to the recent Common Kevin levels chief executive should include Shiau, S.-Y. (Ed.), Proceedings of the fish nutrition
lications was carried out. working dataset. In order to standardise the data onto a Fisheries Policy Reform, pre- of Astec says, “We have previ- on supporting start-up symposium, pp. 51-77. www.astecaquaculture.com
Figure 4. clearly adequate levels so an obvious businesses Website:
This search yielded 286 papers of which This highlights the limited scope of many common ground, two different modes of Therefore experiments should be plateau can be
249 were original research studies focusing studies and/or scientific manuscripts and expression (percentage of EAA of interest designed to produce such result curves. observed.
on EAA requirement of teleosts.
As expected, a great variety of objec-
the uneven quality of the research effort.
An important cause of rejection of studies
in the dry diet, amount of EAA per MJ of
digestible energy) were computed and two
Strong profile in the global feed
For example, data points of a given study
will approach the horizontal line if there is
Concomitantly,
equally clearly
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Amongst selection criteria, studies had of the diets, were frequently not reported analysed using four mathematical models: the company.
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model (SKM) (see Figure 4) in each References
Additionally, if the curve only comes as a result of
study to allow estimation of EAA increases but does not plateau, then the significant increase
Bureau, D.P.,
(a) (b) (95%) requirements. models can only guess where the curves in the demand for
Encarnação, P.,
plateaus or peaks. Since the require- H a m l e t Adequately ’s
2006. P r o t e i n
Preliminary results
and perspective for
ment is estimated by the EAA level products during 2010
where Otto Damholt
defining the amino
Niels the curve plateaus or peaks, such andacid requirements
2011, and to Coming Your Way
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of fish: The case Everything you need to know about
Figure 5 presents the computed reliable. in Horsens, Denmark, quest to deliver the compa-
Based example of lysine. Good Agricultural Practice Certification
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ny’s strategic goals in the high at a place near you!
(c) trout using six studies for which rated very deficient and obviously adequate soyaL.E., Ricque Marie,
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(95%) (d) (95%) D., Tapia Salazar, M.,
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ancies in estimates between the Conclusions Damholt, aged Saturnvej 51 (Eds.), Advances
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September-October 2011 | InternatIOnal AquAFeed | 31 3

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