Preliminary Studies on the Formulation and Presentation of ...

The Fifth Indian Fisheries Forum Proceedings
Us. S. Ayyappan. J. K. Jena and M. Mohan Joseph (2002)
Publtshed by AFSLB, Mangalore and AoA, Bhubaneswar. India
<strong>Preliminary</strong> <strong>Studies</strong> on the Formulation and Presentation of
Compounded Diet to Asian Seabass, Lutes calcarifer (Bloch)
S. Ahamad Ali, K. Ambasankar, J. Syama Dayal,
A. R. Thirunavukkarasu and M. Kailasam
Central Institute of Brackishwater Aquaculture
160, Maholingapuram Main Road, Nungamba&m,Chennai-600 034, Tnmii ,Vadu, India
Abstract
Fingerlings (0.5 to 5.0 g live weight) of Asian seabass (Lates calcarifer) were successfully weaned to compounded diets
fonnulated with fish meal, mantis shrimp (Squilla), soya flour, groundnut oil cake, wheat flour and vitamin-mineral
mixture. It took 7-15 days to wean the fish from the natural food to the compounded diet prepared as granules (0.5 to 1
mm) in dry and semi-moist form. Growth performance of juvenile seabass (initial mean body weight 1.60+0.40 g) fed
with three different formulated diets (CP 35-40%) and control feed prepared with fresh fish meat were determined.
Growth of fish fed with the three compounded diets ranged from 32 to 46% with feed conversion ratios of 2.75-2.90 in a
30 days feeding trial. Total mortality of the fish fed with control feed occurred within 10 days in this particular trial. The
survlval rate of fish at the end of the experiment ranged from 66 to 68 J.
Key words: D~et. formulation, seabass. weaning
Introduction
Asian seabass is one of the important species for
brackishwater aquaculture in India. The potential for the
farming of the species increased many folds in India after
successful achievement of induced breeding technology by
the Central Institute of Brackishwater Aquaculture,
Chennai, India. Presently the culture of seabass in growout
systems relies mainly on fresh trash fish due to nonavailability
of formulated commercial feeds. Daily
procurement of fresh fish, storage and handling are some of
the practical problems involved in the use of trash fish.
Hence, there is a need to develop nutritionally balanced
compounded feeds for the culture of seabass. Knowledge
on the nutritional requirements of candidate fish and their
feeding behaviour are the critical factors to formulate
practical and cost-effective compounded feeds for farming
fish in general. Limited information is available on these
lines at present in case of seabass. Being a carnivorous and
predator of live-prey in feeding habit, weaning to
compounded diets is an essential task. The present study
was undertaken to study the means of weaning seabass to
compounded diets and their presentation for acceptability
and growth of fish.
Material and Methods
Preparation of weaning &st diet
Taking into consideration the feeding habit of
seabass, attempts were made to prepare floating or slow
sinking type of diet to simulate a moving prey. To achieve
this objective a diet was formulated with selected
ingredients (Table 1). Dry ingredients were individually
powdered and passed through 0.2 mm mesh sieve. Except
wheat flour all other ingredients were mixed together.
Wheat flour was made into a paste in boiling water (50 rnl
for 100 g of diet), cooled and mixed with the diet mixture.
Yeast was soaked in water (200 ml) and then added to the
diet mixture. After thoroughly kneading the feed mix into
dough it was allowed to stand at room temperature for half
an hour for fermentation after which it was extruded
through a hand pelletizer by using 2 rnm die. While one
part was stored in the freezer to be used as moist diet and
another part was dried under high vacuum at 4PC.
Weaning trial
Hatchery reared fingerlings of Asian seabass (Lutes
calcarifer) from a single brood were used in the
experiment. The fish were raised by feeding Artemia
nauplii initially in the hatchery and subsequently weaned to
fish meat in the nursery. The weaning trial was conducted
on two size groups of fish with mean initial weight of 0.5 g
and 5.0 g. FRP tanks of 100 1 capacity containing clean
seawater were used during the experimental trials and each
tank contained 20 fish: The experiment was carried out in
triplicate tanks. The weaning trial was conducted in three
ways, one by providing dry diet (granules of 0.5 mrn size),
second by moist diet and third by mixing the diet with fish
meat gradually increasing the proportion of compounded
diet by 10%. The duration of the experimental trial was 15
days.

Table 1. Ingredients and proximate composition of seabass
weaning diet
Ingredients %
Fish meal 40
Squid meal 10
Soybean meal 10
Groundnut oil cake
F~sh oil
Vegetable oil
Lecith~n
Wheat flour
Wheat bran
Yeast
Aminoacid mix'
Vitamin mix'
Mineral mix'
Total
Prox~mate composition
Mo~sture 7.30
Crude protein 37.06
Crude tibre 8.31
Ether extract 8.91
Total ash 7.10
NFE 31.32
1. Amino acid mlx Lysine. Methionine, Glutamic acid in the ratio of 1: I:l
2 Vitamin mix (mgtkg) : Thiamine 20.0, Riboflavin 25.0, Pyridox~ne 20.0,
Pantothen~c acid 50.0. Niacin 150.0. Folic acid 10.0. Cyanocobalamine
0.02. lnosltol 2C0.0. Choline chloride 500.0, Biotin 1.0. Ascorbic acid
2(M).O. Vitamin A4.0 (6000 i.u), Vitamin E 50.0 and Vitamin K 10.0.
3. M~nenl mix (glkg): Calcium 5.0. Phosphorus 7.0. Magnesium 0.5,
Sodium 2.0. Potassium 2.0. Sulphur 4.0. Chloride 3.0, Iron 0.1, Copper
2.0. Manganese 0.025, Cobalt 0.01, Zinc 0.1 and Iodine 0.2
Growth experiment
After successfully evolving the process of weaning
seabass to formulated diet, three diets were formulated to
study the acceptability of feed and their growth
performance. Ingredients used and proximate composition
of test diets are presented in Table 2. The diets were
prepared as dry pellets as described earlier and were
crumbled to 0.5 mm granules. In this experiment juveniles
of hatchery reared seabass with an average weight of
1.60+0.48 g were used. As in the first experiment, 20 fishes
in triplicate were taken in 100 1 tanks filled with seawater.
Each group of fish was weaned to the respective test diet by
the same method of gradually incorporating the fish meat in
the first 10 days. The feeding trial with test feeds was
commenced after this period. Duration of the trial was 30
days. The control group was fed with fish meat
(approximately 10% of body weight on dry weight basis).
Test group of fish were offered feed approximately at 10%
of their body weight divided in three rations.
Weight gain, specific growth rate (SGR) and feed
conversion ratio (FCR) were determined at the end of the
experiment. Proximate composition of test diets was
analysed by following the methods of AOAC (1990).
Table2. Ingredients and proximate composition of test diets
for seabass
Ingredients Diet-2 Diet-3 Diet-4
(%) (%) (%I
Fish meal 20.0 30.0 40.0
Squilla nzeal 5.0 5.0 5.0
Soybean meal 17.0 12.0 12.0
Groundnut oil cake 15.0 10.0 10.0
Fish oil 4.0 4.0 4.0
Sun flower oil 3.0 3.0 3.0
Lecithin 1 .O 1 .O 1 .O
Wheat flour 20.0 20.0 15.0
Wheat bran 10.5 11.7 6.7
Aminoacid mix* 1.5 0.3 0.3
Vitamin mix* I .O 1 .O I .O
Mineral mix* 2.0 2.0 2.0
Proximate composition
Moisture 8.11 . 8.23 8.35
Crude protein 34.94 35.76 39.63
Crude fibre 3.26 2.93 2.91
Ether extracl 9.5 1 9.08 9.62
Total ash 12.43 14.59 18.63
NFE 31.75 29.41 21.86
* The composition are same as in weaning diet as given in Table I
Water temperature and salinity during the
experiment were in the range of 27-29°C and 25-28 %o,
respectively. Dissolved oxygen and pH in the rearing tanks
were 7.2-8.0 mgA and 7.8-8.1, respectively. Data obtained
in the experiments were subjected to one way ANOVA on
the SAS package for the IBM-PC (SAS Institute Inc.,
1988).
Results
Weaning trial
The method of preparation of diet adapted in this
study resulted in the desired physical properties.
Formulation of diet and subsequent vacuum drying resulted
in puffy texture in the dry diet. The diet pellets floated 2-3
minutes and started sinking slowly. Feeding the weaning
diet directly resulted in poor acceptability by fish both in
the dry as well as moist form. Gradually mortality had set
in after one week in both the treatments. However, the fish
fed with a mixture of diet and lish meat started accepting
the diet right from the beginning. The fish offered dry and
moist diet directly emaciated due to starving and the
survival of fish was reduced to 20% in the case of dry diet
and 40% in the case of moist diet (Fig. 1) in the smaller
group (0.5 g). In larger group (5.0 g), the respective
survival levels were 30% and 50%. In both the cases the
moist diet appears to score over the dry diet. On the other
hand the survival levels recorded with mixed diet after 15
days of rearing were 80% in smaller and 90% in larger size

groups. In the case of mixed diet, within 10 days the fish
could be fed with 100% diet. totally replacing the fish meat
in Group I fish. In case of Larger group (Group 11) the total
rtplacemenr of fish meat with diet could be achieved in 7
days. Once the fish was weaned to formulated diet it
accepted the diet in dry as well as moist forms. Even the
feed kept at the bottom of the tank was consumed.
Observations had shown that moist diet was more readily
consumed compared to the dry diet.
Dry del Moistd~et D~el+F~shma'
Weaning methods
Fig 1. Survival (%) of seabass fingerlings fed with weaning
diets in three different ways at the end of 15 days
Growth
The results of 30-days feeding trial with three
growth diets are presented In Table 3. The growth of fish
improved with the increased fishmeal level in the diet. Diet
having 39.63% crude protein gave significantly (P < 0.05)
higher growth (46%) and better FCR of 2.75. The FCR did
not show any significant difference between the treatments
(P > 0.05).
Table 3. Weight gain, SGR, FCR and survival levels of
seabass fingerlings fed on test diets for 30 days
Average Diet-2 Diet-3 Diet-4 Control
In~tial ave. live 1.57a.31 1.634.42 1.624.38 1.604.43
Wt.(g)
Ftnal average 2.07-cO.41 2.244.49 2.37k0.42 -
live wt.(g)
Wetght gain (%) 32~k1.9198+21 46k2.27'
FCR 2.90d.09" 2.904. 1097550.1 I" -
SGR (5%) 0.91d.O 1 1.05&0.02 1.26kO.02
Surv~val (%) 66 68 66 lOO(on
10th davl
'Menns bennng the dtfferent superscript in the sane row d~ffer
s~gntficantly (P c 0.05)
The survival levels were in the range of 6648% in
the different treatments. However, total mortality of fish
occurred within ten days in the case of control d ~ (fish e ~
meat). A striking observation made during feed trial was
that in the case of control diet, the dead fish mas consumed
by the live ones (cannibalism), whrle in case of formulated
diets this tendency was not noticed.
Discussion
Seabass seems to be conservative ir, its feeding
habit. It is tough to change from one type of dret to another
type. Unless the diet is acceptable to the fish. it prefers to
starve rather than to eat whatevcr comes its way In the
present study, by allowing short time fermentation of feed
through yeast and subsequent vacuum drying. puify texture
could be imparted in to the pellets, especially in dry pellets.
This had resulted pellets floating for 2-3 mlnutes and then
sinking slowly after absorb~ng sufficient water. Th~s was
resorted mainly to simulate the slow-s~nking pellet as
moving prey. Although seabass prefers to feel on moving
prey, the sinking pellets in dry or moist form d~d not attracl
the fish adequately to feed on At times, even IF it takes diet
pellets into its mouth, it lmmedlately spits out The
attractability and texture of teed seems to bc inore
important factors. Since fishmeal was presenl In the
weaning test diet in the present study, it had fishy flavour
and the moist diet was soft in texture. St111 the diet was not
acceptable to seabass when fed alone. Out of the different
ways of weaning tried, incorporation of the diet in the fish
meat and gradually replacing the later finally succeeded in
adopting the compounded diet by the fish wh~ch took 7-15
days. Once the fish adapted to the formulated d~et it
accepted dry as well as moist fo~m of the diets directly.
References in this line on seabass are scarce. Investigations
cmied out on seabass (Cuzon and Fuchus, 1988; Sakaras er
al., 1988; Tucker et al., 1988, Cuzon et nl., 1989:
Mackinnon, 1989; Wong and Chou, 1989: Perez et al.,
1993; Boonyaratpalin, 1991; Catacuttan and Coloso,
1995,1997) did not bring out any of the aspects associated
with weaning of seabass to formulated diets. The present
study suggested that Asian seabass could be weaned to
formulated feeds by incorporating fish meat with
formulated diets within a per~od of 7-15 days. Once
adopted the fish easily accepts formulated diet. The results
also indicated that weaning may be faster as the size of the
fish increases.
In growth trial conducted with formulated feeds on
fingerlings, the method evolved for weaning the fish to
formulated diet was successfully adopted All the three
diets formulated and tested were accepted by the fish and
supported the growth. Since the pellets are made to sink
slowly, the fish readily swallowed the diet, once they were
adopted to eat. Fish consumed even the diet settled at the
bottom of tank. The results suggest that adaptation of fish to

the d~et plays Important role than the other physical
characterlstt~s of the dtet such as floatlng and slow sinklng
It 1s common knowledge that most of the finfish specles
actively feed on floatlng feeds Seabass belng a predator of
movlng prey and feeds mostly In the water column, the
requirement of physical character~st~cs of feed for seabass
needs fu~ tlier understand~ng
One Interesting observat~on made dunng feedlng
tr~al was that m the group of fish fed wlth control d~et (fish
meat) the dead fish was ~onsumed by the remalnlng fish
rnd~cat~ng cann~bal~stic tendencies Howevet, in the case of
formulated d~et fed groups the dead fish were recovered
w~thout belng consumed by others Th~s may suggest that
cann~ballsm can be avo~ded In seabass by adopt~ng the fish
to formulated d~ets
Among the three feeds tested, the fingerl~ngs of
seabass fed on d~et wlth 39% crude protein showed a higher
welght gain and better FCR Catacuttan and Coloso (1995)
Cuzon G, R Chou and J Fuchus 1989 Nutrltton ot the seabass
reported that diet w~th 50% protein and 15% lipid reco~ded
Lutes caicairfe~ 111 Advan~es In Tropl~~l Aquaculture
h~gher we~ght gain and better FCR In AsIan seabass (Eds J Barret J Calvas G Cuzon J Fuchus and M
Slm~lar studles on seabass suggested that the dret with 45- Weppe), Aquacop, Tah~t~, pp 757-761
55% crude proteln, 16-18% lipid and 10-16% carbohydrate Macklnnon M R 1989 Status and potentla1 ot Aublralian Lores
gave better growth and FCR The we~ght gan of 46% calca~rjei culture 111 Advance\ III Troplidl Aqud~ulture
recorded In 30 days by D~et-3 in the present study IS lower (Eds J Barret J Calvas G Cu~on .i Fuihus dnd M
than the we~ght galn repo~ted by Catacuttan and Coloso Weppe), Aquacop, Tahit~ pp 713-727
(1995. 1997) The varlatlon in the weight gain may be due Perez, L, D Cano, M Jover and J Fernadez 1993 Growth
to the difference in the proteln levels of the diet used In prelirn~nary result of seabass fingerlings ted w~lh cooked
extruded dlets of several levels ot protlen carbohydrate
thelr stud~es D~et-3 had only 39% proteln whlle the d~ets
and lipids In Actas del IV Congreso Natinal de
used by Catacuttan and Coloso had higher protein (50%) Aquicultura (Eds A Cervlno, A Landln, A de Coo A
levels Due to slmllar reasons the d~et In the present study
recorded higher FCR values compared to the diets wth
Guem and M Torre), Centro de Invest~gaclones Mannas
Pontevedra, Spmn, pp 97-102
higher protein levels
Sakaras, W M , M Boonyaratpalln N Unprasert and P
The results of the plesent study lndlcated that
seabass can be weaned and adopted to formulated feeds,
Kumpang, 1988 Optlmum dietary proteinlenergy ratlo In
seabass feed I Techn~cal Paper No 7 Rayong
Brack~shwater Flshenes Statton Thatland, 20 pp
which can support the growth of fish Further, the study SAS Instttute Inc , 1988 SASISTAT Usei'gulde Release 6 03
also Indicated that the incidence of cann~ballsm appears to
be hlgh In fish fed w~th fish meat, whereas such tendency
was not observed w~th formulated dlets However, further
studies are necessary for Improvement In nutrit~onal levels
edihon SAS Inst~tute Inc , Cary NC 1028 pp
Tucker, J, M Mackinnon, D Russell, J O'Brien, and E
Cazzola, 1988 Growth of juven~le balan~undi (hres
calca>lfe) on dry feeds P~og Frslz Crtlr 50 81 -85
for achlevlng faster growth and FCR of seabass
Acknowledgements
The authors exprebs thew sincere thanks to Dr G R
M Rao, Director, Central Institute of Bracklshwater
Aquaculture, Chennai for h~s encouragements In carrying
out this work
References
AOAC 1990 Offictal Methods ot Analys~s 15' edlt~on
Assoc~ation ot Official Analytt~al Chemists Washington
D C
Boonyaratpalln, M , 1991 Nutntlondl studtes on seabass (Lures
calcaerfel) h F~sh Nulr~t~on Reseatch in Asla
Proceedtngs ot the Fourth Asian Flsh Nutrttion Workshop
(Ed S S De S~lva), AsIan Ftsher~es So~~ety, Manila
Phll~pplnes, pp 33-41
Catacuttan M and R Coloso 1995 Etfe~t of d~etary protein to
energy ratlos on growth sur\lvdl and body co~npositlon of
juvenrle As~an seabass, Lire5 calca~!fei Aglca~ltln~re
131 125-133
Catacutm, M and R Coloso 1997 Growth ot juvenlle AsIan
seabass, Lazes cnlcn~rfe~ ted varylng ~arbohydrate and
prote~n levels Aquaculrzlre 149 137 144
Cuzon, G and J Fuchus, 1988 Prel~rnlnar) nutnt~onal stud~es ot
seabass Lates calcargeer (Bloch) proteln and 11pld
requirements h~ 19Ih Annudl Conference 2nd Expostt~on
World Aquaculture Soc~ety Hawall pp 15 16
Wong, F J and R Chou 1989 Dleta~ y proteln requliements ot
early grow-out seabass (Lares rnicurfel Bloch) dnd some
observation .on the performance of two pract~~ai
formulated feeds Smgal~ore J Pi I Irld ,17 (2) 98-111