The document summarizes a study that assessed the effects of incorporating corn gluten meal (CGM) into diets for rainbow trout on flesh pigmentation. The study found: 1) Incorporating 19% CGM into the diet had no significant effect on fish growth performance or feed efficiency compared to the control diet. 2) While flesh astaxanthin levels were significantly lower in fish fed the CGM diet, instrumental colorimetric analysis found no significant differences in flesh color between the two diet groups. 3) No lutein or zeaxanthin (yellow xanthophyll pigments present in CGM) were detected in the flesh of fish from either diet group. The results suggest

1. March | April 2011
Feature title: Effects of Corn Gluten Meal on Flesh Pigmentation of Rainbow Trout
International Aquafeed is published five times a year by Perendale Publishers Ltd of the United Kingdom.
All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies,
the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of
information published.
©Copyright 2009 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form
or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058
The International magazine for the aquaculture feed industry

2. F: Pigmentation F: Krill
F: Pigmentation
trying to harvest the zooplankton, production Norwegian-based
increasing levels of CGM + soybean meal growth and feed efficiency, as wellliterally nothing to 528,000 tonnes
rose from as flesh after slaughter. Instrumental colorimetric
Aker BioMarine,
was observed. pigmentation and astaxanthin concentration
by 1982. analysis of fillets was which harvested
performed with a
Conversely, Olsen and Baker (2006) of rainbow trout. tristimulusbeset by
The industry, however, was colorimeter. 50 percent of the
observed no effect of increasing dietary Two isoproteic and numerous problems, least Measurements were total caughtthree
isoenergetic (on a of all being the processed at in
lutein levels (0, 11, 23ppm) on muscle astax- digestible basis) practical diets wereoffor- required to undertake point below the lateral
huge amount fuel points over and tree 2010 according to
anthin concentration of Atlantic salmon fed mulated to meet all the known nutrient and then remaining on midway between the
journeys to Antarctica line: close to the head; CCAMLR statistics.
a diet containing 55ppm astaxanthin. requirements of rainbow troutcatching and processing. the tail; and close to the the krill
site for (see Table head and Much of tail. All
Absorption of lutein was very low com- 1). A control diet (Diet 1) It collapsed for the most part after the performed in the colori-
was formulated measurements were fishery depends on
pared to that astaxanthin in these fish. to contain no corn gluten meal the USSR, which had been able to
demise of while a metric space L* (lightness, L*=0 for black,
large trawl nets with
However, these authors identified a test diet (Diet 2) contained 19 percent operation for white) with very fine meshes,
bankroll its expensive L*=100 without an a* scale represents
weak but non-significant tendency of lower corn gluten meal (see Table 1). The diets
eye towards profit. the intensity in red, and producing a very
b* scale represents
flesh astaxanthin content in fish fed feed were supplemented with 50 ppm oflate 1990s, the intensity in yellow. The hue is an angular
In the astax- the controversial high drag that gen-
with 23ppm lutein. anthin (Carophyll® Pink, DMS Nutritional Moon stepped in, organ- 0° erates a 0) denotes
Reverend Sun Myung measurement where (H°ab= bow wave,
Products) and steam pelleted to appropri- Ocean tohue and krill (H°ab= 90) denotes the
ising Alaskan-based Top the red fish for 90° deflecting the krill to
Experimental design ate size using a laboratory pellet mill. that krill meal could The C* is an expression of satura-
with the idea yellow hue. feed the the side.
A 12-week growth trial was recently Rainbow trout (Oncorhynchus mykiss),
world’s population. tion or intensity and clarity of the colour. fine
In addition,
conducted at the UG/OMNR Fish Nutrition weighing 132g/fish, were reared at 15°C in
Although Top Ocean’s factory trawler mesh trawls tend
Research Laboratory to assess the effect (25 fish/tank) part Analysis of Carotenoids
four 500L plastic tanks worked the Southern Ocean grounds from to clog very fast,
of CGM incorporation in the diet on 2000 to 2004—and by HPLC
of a freshwater recirculation aquatic system. even won an award and perhaps worse,
Each atexperiment diet
the Boston Seafood Show with its krill the diets and muscle
Carotenoids from the tiny mesh size
was products—Top two
allocated to Ocean’s owners decided not
samples were extracted, separated and
Effects of Corn Gluten Meal
catches everything
Table 1: Formulation, analyzed chemical composition and tanksto pursue it. hand
and the fish quantified by HPLC within its path, leading to
short C30 column
pigment content of experimental diets.
fed to near-satiety two (YMC Carotenoid, Water, large by-catch.
However, since then Antarctic krill indus- a Mississauga, ON).
Diets timestry has picked itself up and is expanding
a day for 12 weeks. The separated carotenoidsOnce detected
were caught
on Flesh Pigmentation of Rainbow Trout A
and measured at 450nm, and the net, two
with catches around 200,000 tonnes, shared in the identifica-
Ingredients (g/100 g diet) 1 2
Instrumental Norway, South
mainly between tion of Korea, Japan,
the carotenoids problems on the
was based occur.
Fish meal, herring, 68% CP 28 16 ColourPoland.
and Analysis congruence of retention times and early
Krill caught UV/
vis spectra tonnage
Fish The increase in sustainable catch
were manually with those during the run will
of pure authentic
by Patricio Saez1*, El-Sayed M. Abdel-Aal2 and Dominique P Bureau1 Corn gluten meal, 60% CP - 19
standards.
skinned largely due to krill fishing innovations by
and filleted right I
1UG/OMNR Fish Nutrition Research Laboratory, Dept. of Animal and Poultry Science, University of Guelph, Guelph, Poultry by-product meal, regular 15 11.5 is be compacted and
o
Ontario, N1G 2W1, Canada. Soybean meal, 48% CP 10 15
t
2Guelph Food Research Centre, Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Feather meal, steam-hydrolyzed 6 4
m
Canada. Blood meal, whole, spray-dry 2 2
*Corresponding author, email: psaez@uoguelph.ca Brewer's dried yeast 6 6 Krill Canada Sales Corp. e
Wheat middlings, 17% CP 12.4 8.9 North America’s largest supplier of I
F
Fish oil, herring 12 12 krill products! C
ish culture operations around and the importance of pigmentation on imparting an undesirable yellowish hue
the world are confronted to final product quality, the impacts of feed to the flesh and/or by reducing efficiency Vegetable oil 4 5 i
the significant challenges of ingredients on flesh pigmentation of salmon of utilization of the expensive carotenoid Vitamin premix 1 1
Krill usage C
 Smoult sea water entry diets
managing their production
- CALING a
and trout is an issue that deserves more pigments incorporated in the diet. However,
costs and ensuring that the quality of attention. the results of most studies published so far
Biolys® (52% lysine) 1 1.5
UP S
 Weaning and broodstock diets
DL-Methionine, feed-grade 0.5 0.5  Starter diets for marine and fresh water species
their products meets the high stand-
ards that consumers demand.
Corn gluten meal (CGM) is a by-product
of the corn wet milling process with high
have been equivocal.
Skonberg et al. (1998) observed that fil- Mineral premix 0.5 0.5
AQUACULTURE SYSTEMS
 Fin fish growth: color, taste, stimulate eating and breeding
 Crustaceans: growth and brood stock productivity with
Optimising system size for enhanced supplements
protein and low phosphorus contents, high lets from rainbow trout fed a diet contain- Ca(H2PO4)2 1.5 1.5  Tropical fish: whole feed and supplement feeds
environmental equilibrium
In response to high price of fishmeal and digestibility and consistent quality which ing 22 percent CGM (and no supplemental Carophyl pink (8% astaxanthin) 0.0625 0.0625  Invertabrates: whole feed
other feed ingredients, feeds for salmon and makes it a valuable ingredient for fish feed synthetic pigments) had a higher ‘yellow’ August 17-18, 2011. Trondheim, Norway.
 Fish bait and attractants
trout have been progressively formulated formulations. Other corn products, such colour value (measured by Tristimulus Analyzed composition (% dry matter) Within AQUA NOR 2011, 16-19 August 2011
to contain increasing levels of economical as corn distillers dry grains and soluble colorimeter) and received significantly
(DDGS), are also finding increase use in lower preference scores than that fish Dry matter 94.0 93.9
protein sources. AQUA NOR Forum - presentation of the issues, discussion of the solutions
While the effect of various protein aquaculture feed formulations. fed a diet without CGM or a diet with Crude protein 50.9 50.6 I.Up-scaling land-based systems
Our products include
sources on growth performance and nutri- Anecdotal evidence from feed manufac- 22 percent CGM supplemented with syn- Lipids 23.8 23.1  Fresh Frozen Pacifica(marine) cage systems
II. Up-scaling Krill
ent utilization of fish has been the focus of turers suggests that high dietary incorpora- thetic pigment (100 ppm canthaxanthin). Digestible energy, MJ/kg (estimated) 20.1 20.6  Fresh Raw Frozen Superba Krill
III. Up-scaling the ecological approach to production
much research, relatively limited effort has tion levels of CGM or other corn products Mundheim et al (2004) found a significant  Fresh Boiled Frozen Superba Krill
been invested in assessing the effects of may negatively affect flesh pigmentation in linear reduction in the colour (assessed  Fresh Shell off Frozen Superba Krill
different feed ingredients on product quality. fish. using the Roche color fan) of fillets of Analyzed pigment concentration (mg·kg-1 dry matter) Organised by the European Aquaculture Society, with
 Superba Krill Meal
Flesh pigmentation is a crucial quality CGM and other corn milling by-products Atlantic salmon fed diets (supplemented
Astaxanthin 48.2 56.7 For more information & our full product range, visit:
criterion of farmed salmon and trout. The contain relatively high levels (100-500 ppm) with 64ppm astaxanthin) with increasing
www.krill.ca
Lutein ND 28 www.easonline.org
expensive pink or red carotenoid pigments of yellow xanthophyll carotenoids, mainly replacement of fishmeal by a combination
(astaxanthin, cantaxanthin) included in the lutein and zeaxanthin. Observations scat- of CGM and soybean meal (2:1 ratio) in Zeaxanthin ND 15
diet represents between 10 to 20 percent tered in the scientific literature suggest diets. �-cryptoxanthin ND ND
of the costs of salmon and trout feeds. that xanthophyll carotenoids may impair A linear reduction in growth and feed �-carotene ND ND
Given the very high cost of these pigments pigmentation on salmonid fish, either by efficiency of the fish fed the diets with
North America’s largest supplier of krill products!
ND = not detected
18 | InternatIonal AquAFeed | March-april 2011 March-april 2011 | InternatIonal A
32 | InternatIonal AquAFeed | March-april 2011 March-april 2011 | InternatIonal AquAFeed | 33 ET-210B.indd
Krill_90x132mm.indd 1 21/02/2011 11:07

3. F: Pigmentation
GROWiNG iS
Results to that of the fish fed the control diet. The results of the present study
CGM inclusion in the diet had no signifi- This suggests an adverse effect of CGM support the anecdotal evidence that
cant effect on growth and feed efficiency of inclusion on flesh astaxanthin deposition. yellow xanthophyll pigment present in
the fish (see Table 2). On average, rainbow No lutein and zeaxanthin were detected corn products may have the potential
trout grew from 132g to 535g during the in the flesh of the fish fed the two diets to negatively affect flesh pigmentation of
12 weeks trial, representing an average (see Table 3). salmonids.
thermal-unit growth coefficient (TGC) of The absence of significant differences The results from the present and
beautiful
0.240, with a feed efficiency (gain:feed) of for any of the colour attributes measured other studies suggest a possible interac-
0.89. by colorimetric analysis between muscles tion between xanthophyll pigments and
Tristimulus colorimetric analysis did from fish fed Diet 1 and Diet 2, even astaxanthin. The potential mechanisms
not show significant (P>0.05) differences though the former contained a significantly (e.g competitive inhibition during intes-
for any of the colour attributes meas- (p<0.05) lower astaxanthin concentration tinal absorption, transport in lymphatic
ured for the flesh of fish fed Diet 1 and is perplexing. lipoproteins, or deposition in muscle
Diet 2, suggesting that the incorporation However, this phenomenon has been fibre cells) have not been studied (Olsen
of CGM had not effect on flesh pigmen- reported in the past for rainbow trout and Baker, 2006).
tation (see Table 3). (Choubert et al, 2009). Numerous fac- It is worth noting that the xanthophyll
However, analysis of carotenoid pig- tors, such as muscle light scattering pigments concentration in CGM used
ments by HPLC revealed significantly and absorption, can affect salmon flesh in the present study was relatively low
(p<0.05) lower astaxanthin concentration colour. Colour and pigment concentra- (142mg·kg-1). Much higher xanthophyll
of the flesh of fish fed the diet containing tion are not always perfectly and linearly concentrations (224 to 550mg mg·kg-1)
19 percent CGM (Diet 2) compared related. have been reported among different
batches of CGM (Park et al., 1997).
Table 2: Growth performance and fed efficiency of rainbow trout (IBW=132 g/fish) fed Discrepancies between studies may be
experimental diets for 12 weeks. related to differences in dietary xan-
Diet 1 Diet 2 thophyll carotenoid concentrations and
Parameter types (e.g. lutein vs. zeaxanthin).
The effects of yellow xanthophyll
Final body weight 540 ± 29 531 ± 5 pigments on pigmentation of the flesh
Gain (g/fish) 402 ± 27 400 ± 4 of salmonid fish remains very poorly
characterized and more systematic
Feed efficiency (gain:feed)1 0.91 ± 0.05 0.88 ± 0.05
work needs to be carried out on this
TGC2 0.239 ± 0.01 0.243 ± 0.01 issue.
Data are mean ± Standard deviation, n=2 tanks.
1Feed efficiency (live weight gain:dry feed intake), 2TGC=thermal unit growth coefficient. References
No significant differences observed. Bjerkeng, B., Følling, M., Lagocki, S., Storebakken,
T., Olli, J.J., Alsted, N., 1997. Bioavailability of
all-E-astaxanthin and Z-isomers of astaxanthin
Table 3: Fillet carotenoid concentration and retention, and colour of rainbow trout fed in rainbow trout (Oncorhynchus mykiss).
experimental diets for 12 weeks.
Aquaculture 157, 63-82.
Initial Final
Choubert, G., Cravedi, J., Laurentie, M., 2009.
Effect of alternate distribution of astaxanthin on
Fillet colour attributes Diet 1 Diet 2 rainbow trout (Oncorhynchus mykiss) muscle
pigmentation. Aquaculture 286, 100-104.
L* 45.9 ± 1.8a 40.5 ± 0.6b 40.4 ± 1.4b Mundheim, H., Aksnes, A., Hope, B., 2004. Growth,
a* 1.3 ± 1.1b 9.9 ± 1.3a 9.6 ± 0.7a feed efficiency and digestibility in salmon (Salmo
salar L.) fed different dietary proportions of
b* 4.8 ± 1.4b 13.4 ± 0.5a 12.8 ± 1.0a
vegetable protein sources in combination with
H°ab 76.1 ± 11.5a 53.6 ± 2.6b 53.2 ± 0.1b two fish meal qualities. Aquaculture 237, 315-331.
C* 5.0 ± 1.6b 16.6 ± 1.2a 16.0 ± 1.2a
Olsen, R.E., Baker, R.T.M., 2006. Lutein does not
Fillet carotenoid concentration influence flesh astaxanthin pigmentation in the
(mg·kg-1) atlantic salmon (Salmo salar L.). Aquaculture 258,
558-564.
Astaxanthin NDc 5.6 ± 0.5a 3.2 ± 0.5b Park, H., Flores, R.A., Johnson, L.A., 1997.
Preparation of fish feed ingredients: Reduction
Lutein ND ND ND
of carotenoids in corn gluten meal. J. Agric. Food
FRANCE / 00 33 2 97 40 42 09
Zeaxanthin ND ND ND Chem. 45, 2088-2092.
β-cryptoxanthin ND ND ND Skonberg, D.I., Hardy, R.W., Barrows, F.T., Dong,
β-carotene ND ND ND F.M., 1998. Color and flavor analyses of fillets Our hydrolysates have a superior concentration of Natural Active NutrientsTM
from farm-raised rainbow trout (Oncorhynchus
Data are mean ± standard deviation, n=2 tanks, means of 5 individuals per tank. Thanks to their biological action on fish and shrimp growth mechanisms,
mykiss) fed low-phosphorus feeds containing corn
ND = Not detected. or wheat gluten. Aquaculture 166, 269-277.
they boost your feed performance and help you substituting fish meal.
34 | InternatIonal AquAFeed | March-april 2011 contact@aquativ-diana.com - www.aquativ-diana.com

4. LINKS
This digital re-print is part of the March | April 2011 edition of International Aquafeed magazine.
Content from the magazine is available to view free-of-charge, both as a full online magazine on our
website, and as an archive of individual features on the docstoc website.
Please click here to view our other publications on www.docstoc.com.
Vo l u m e 1 4 I s s u e 2 2 0 1 1
• See the full issue
Aquaculture:
• Visit the International Aquafeed website
Producing aquafeed pellets
Krill:
Feed makers need to look at krill
Feed Management:
• Contact the International Aquafeed Team
An assessment of aquaculture production with
special reference to Asia and Europe
Pigmentation
Effects of Corn Gluten Meal on Flesh
Pigmentation of Rainbow Trout
• Subscribe to International Aquafeed
the international magazine for the aquaculture feed industry
To purchase a paper copy of the magazine, or to subscribe to the paper edition please contact
our Circulation and Subscriptions Manager on the link above.
INFORMATION FOR ADVERTISERS - CLICK HERE
www.aquafeed.co.uk