Nutritive value of Leucaena leaf meal in
Aquaculture, 62 (1987) 97-108
Elsevier Science Publishers
97
B.V., Amsterdam
-
Printed
in The Netherlands zyxwvutsrqponmlkjihgfedc
Nutritive Value of Leucaena Leaf Meal in Pelleted
Feed for Nile Tilapia
KOK LEONG WEE and SHU-SEN
WANG’
Division zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
of zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Agricultural and Food Engineering, Asian Institute of Technology, G.P.O. Box 2754,
Bangkok 10501 (Thailand)
‘Present address: Shijiazhuang
(People’s Republic of China)
(Accepted
19 September
Institute
of Agricultural
Modernization,
P.O. Box 185, Hubei
1986)
ABSTRACT
Wee, K.L. and Wang, S.-S., 1987. Nutritive
tilapia. Aquaculture, 62: 97-108.
value of Leucaena
leaf meal in pelleted feed for Nile
An experiment was conducted to determine the suitability of treated Leucaena leucocephala
leaf meal as an ingredient for Nile tilapia, Oreochromis niloticus Linn., feed. Nine experimental
diets were formulated to contain 25%, 50% and 100% of the total dietary protein as plant protein
using soaked (soaked in water at 30 oC for 48 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK
h ) , sundried (sundried for 2 days) and commercial
Leucaena leaf meal, balanced by protein from fish meal. A control diet with fish meal as the only
protein source was included. All diets were isonitrogenous
(30% protein) except for diets containing 100% plant protein (21% protein). The 70&y feeding trial was conducted with duplicated treatments
in 2-m3 circular concrete tanks with recirculating water. There was a trend of
reduced growth performance and feed utilization efficiency with increase in Lezuxena leaf meal
incorporation
for all treatments.
Generally, soaked leaf meal gave a significantly better growth
response than sundried or commercial leaf meal. Mimosine present in the latter two treatments
may have contributed to the poorer growth.
INTRODUCTION zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
The increasing cost of fish feed has focused research on reducing the cost of
the most expensive item, the protein source. Numerous works have been
reported on the possible replacement of fish meal which is used at a high level
in most fish feeds (Tacon, 1981: Jackson et al., 1982). Leaf meal from LRucaena zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
leucocephatu is a potential source of protein. It is a vigorous and droughtresistant leguminous tree whose high-protein leaves have been widely used in
animal feeds, particularly for ruminants in the tropics. However, the presence
of the toxic amino acid, mimosine, has limited its use. Published evidence on
the nutritive value of lkucaena leaf meal to fish is conflicting. Pantastico and
0044- 8486/87/$03.50
0 1987 Elsevier
Science Publishers
B.V.
TABLE 1
Composition
of experimental
diets (g/l00 g)
Leucaena
Diet
leaf meal
Control
Soaked
1
2
Commercial
Sundried
3
4
5
6
7
8
100.0
25.0
Plant protein as % of
0.0
25.0
50.0
50.0
100.0
25.0
total protein zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
44.0
lkumena leaf meal
31.0
61.0
90.0
61.0
90.0
31.0
Fish meal
24.0
37.0
50.0
37.0
24.0
37.0
3.1
4.2
4.7
3.6
Fish oil (freshwater
3.6
4.2
4.8
3.6
fish)
Corn oil
4.1
5.0
3.7
2.4
3.7
2.5
1.3
1.2
7.3
30.0
20.7
4.4
Cassava starch
20.7
4.3
Binder’
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.0
1.0
Vitamin premix’
1.0
1.0
1.0
1.0
1.0
1.0
Mineral premix3
1.0
1.0
1.0
1.0
2.0
2.0
1.0
1.0
Chromic oxide
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
7.9
cr-Cellulose
9
10
50.0
100.0
66.7 zyxwvutsrqponmlkjihgfedcb
90.0
20.0
4.0
4.0
3.6
1.7
1.5
1.0
2.0
0.5
-
2.0
1.5
1.0
2.0
0.5
-
‘Carboxymethyl cellulose.
‘To supply/l00 g diet: thiamine (Bl), 2.5 mg; riboflavin (B2), 2.5 mg; pyridoxine (B6), 2.0 mg; pantothenic acid, 5.0 mg; inositol, 100 mg; biotin,
0.3 mg; folic acid, 0.75 mg; para-aminobenzoic
acid, 2.5 mg; choline, 200 mg; niacin (B3), 10.0 mg; cyanocobalamin
(B12), 0.005 mg; retinol
palmitate (A), 100 000 IU; cr-tocopherol acetate (E) ,20.1 mg; ascorbic acid zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
(C) zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
,50.0 mg; menadione zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK
(K),2.0 mg; cholecalciterol (D3), 500 000
IU.
3To supply/l00 g diet: CaHP04.H20,727.78
mg; MgS0.,.7Hz0,127.5
mg; NaCl, 60.0 mg; KCl, 50.0 mg; FeS0,.7H,O,
25.0 mg; ZnS04.7Hz0, 5.5 mg;
MnS0,.4Hz0,
2.5 mg; CuS04.5H,0, 0.79 mg; CoS0,7H,O,
0.48 mg; CaI03.6H,0, 0.3 mg; CrCl,.6H20, 0.13 mg.
99
Baldia (1979, 1980) and Ghatnekar
et al. (1982) reported improved growth
performances
of tilapia species with the inclusion of zyxwvutsrqponmlkjihgfedcbaZYXWVU
Leucaena leaf meal in the
diet. However, Jackson et al. (1982) found that Leucuenu leaf meal as a 25%
replacement of fish meal in a diet for tilapia supported poor growth, which was
attributed to possible toxic effects of mimosine. However, mimosine can be
degraded to a relatively less toxic form, 3-hydroxy-4 (III) -pyridone (DHP ) ,
through various methods of processing, thereby improving the nutritive value
of Leucaena leaf meal. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
MATERIALS AND METHODS
Diets
Ground fish meal and test Leucuenu leaf meal (passed through a 593qm
mesh sieve) were used as dietary protein sources in diets supplemented
with
corn oil, freshwater fish oil, and cassava starch. Three test Leucuenu leaf meals
were used: soaked leaf meal (leaves from a local Thai Leucaenu leucocephula
strain grown on the Asian Institute of Technology campus were submerged in
tap water at an ambient temperature
of 30°C for 48 h and sundried for 12 h) ;
sundried leaf meal ( leaves were sundried for 2 days), and commercial leaf meal
(sundried leaves and stems). The efficacy of these treatments was determined
by measuring the mimosine content of the leaves before and after processing.
Ten experimental
diets were formulated to contain varying ratios of plant to
animal proteins - 25:75, 50:50 and 100:O.
Diet 1 with 100% fish meal protein served as a control, and diets 2,3 and 4;
5, 6 and 7; and 8, 9 and 10 contained soaked, sundried and commercial leaf
meal which contributed 25%, 50% or 100% of the total dietary protein, respectively ( Table 1) . The diets were isonitrogenous
(30% crude protein) and isocaloric (360 kcal/lOO g diet) except diets 4, 7 and 10 (21% crude protein)
(Table 2). The diets were prepared as described previously (Wee and Ng, 1986 ) .
Experimental systems and animals
The feeding trial was conducted in 20 circular concrete tanks of 1.25 m diameter and 0.60 m depth of water, located outdoors under a thatch roof. The water
was recirculated after passing through a mechanical and biological filter. Each
tank was continuously
supplied with freshwater at a mean rate of 7 l/min.
Water temperature,
dissolved oxygen, total ammonia, nitrite and pH were
monitored at Z-week intervals and varied from 26.5-27.O”C, 7.7-8.2 mg/l,
0.6-1.7 pg/l, 0.2 pg/l and 7.9-8.8, respectively. Algal growth, measured as chlorophyll-a, was not detected in any of the experimental
tanks.
Oreochromis niloticus fingerlings (mean weight 3.0 g) were obtained from a
commercial dealer, and acclimatized in the tanks for 2 weeks while fed with
100
TABLE 2
Proximate composition of experimental diets (all values are expressed as %, dry weight basis)
Component
Moisture
Crude protein
Crude lipid
Crude fihre
Ash
NFE’
Mimosine’
Gross energy3
Metabolizable
energy’
Dieta
Control
Soaked Leucaena leaf
meal
Sundried Leucaena leaf
meal
Commercial Leucaena
leaf meal
1
2
3
4
5
6
7
8
9
10
9.6
30.1
10.0
0.92
25.6
12.7
0.00
369.0
291.7
5.0
29.7
10.0
7.3
27.8
11.3
0.00
375.5
294.1
4.9
29.0
10.1
13.2
23.7
9.7
0.00
356.0
283.3
5.3
21.5
9.9
19.2
29.3
5.9
0.00
334.2
255.2
6.2
29.8
10.0
7.0
27.4
11.2
0.71
374.4
293.8
5.4
29.2
10.1
12.9
22.8
9.4
1.34
353.6
282.5
6.0
21.7
9.8
18.7
28.2
5.5
1.61
329.6
253.1
4.9
30.3
10.0
8.8
23.1
12.0
0.48
360.1
287.7
8.8
26.6
9.8
13.1
26.1
9.5
0.66
352.3
275.0
4.6
16.3
7.9
17.0
34.3
6.5
0.72
305.1
221.2
‘NFE: Nitrogen-free extracts = 100 -moisture - crude protein - crude lipid - zyxwvutsrqponmlkjihgfedcbaZYXW
crude fibre -ash.
‘Average values obtained with two eamples each having two replicate determinations.
“Gross energy: in kcal/lOO g, based on 5.7 kcal/g protein; 9.5 kcal/lOO g lipid; 4.0 kcal/g carbohydrate.
‘Metabolixable energy: in kcal/lOO g, baaed on 5.0 kcal/g protein; 9.0 kcal/g lipid; 2.0 kcal/g carbohydrate. zyxwvutsrqponm
pelleted feed (30% crude protein) produced by the National Inland Fisheries
Institute, Bangkok. The fingerlings were randomly distributed between the
tanks at a stocking density of 10 fish/tank, with treatments in duplicate also
arranged at random. At the start of the feeding trial, 20 fish were sacrificed by
a sharp blow to the head, dried in the oven for moisture determination and
stored for subsequent carcass analysis. The experimental fish were weighed
individually at the beginning and end of the feeding trial, but batch weighing
was used at 2-week intervals for feeding rate calculation. Fish were fed twice
daily, 6 days a week, at a fixed feeding rate of 5% wet body weight (dry feed/
body weight) per day, with the feeding allowance adjusted accordingly at 2week intervals. The study was conducted for 10 weeks after which the experimental fish were sacrificed, and fish carcasses taken for gross chemical analysis. In the last week of the experiment, faeces were sampled overnight from
the experimental tanks. Faeces collected from replicate treatments were pooled,
dried in an oven, and stored for subsequent chemical analysis. zyxwvutsrqponmlkjihgfed
Analytical methods
Feed ingredients, experimental diets, and fish carcasses were analyzed for
their proximate composition by the following methods in triplicate: moisture,
determined by oven-drying at 85°C to constant weight; crude protein, determined indirectly from the analysis of total Kjeldahl nitrogen (crude pro-
101
tein=N ~6.25) by the Kjeldahl method [Association
of Official Analytical
Chemists ( AOAC ) , 19841; crude lipid, determined by extraction with diethyl
ether for 6 h in a soxhlet apparatus; ash, determined from weighed samples in
a porcelain crucible placed in a muffle furnace at 550°C for 4 h; fibre content
determined using acid-base digestion ( AOAC,
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM
1984).
For the apparent nutrient digestibility measurements,
chromic oxide was
determined in the faeces and diets using the method of Furukawa and Tsukahara (1966).
The mimosine content of the leaf meal and experimental
diets was determined by the rapid calorimetric method of Matsumoto and Sherman (1951).
To extract the mimosine, samples were digested with 0.1 N HCl, filtered and
clarified by removing plant pigments with activated carbon. Ferric chloride
(0.5% ) was then added to the mimosine extracts to develop a coloured compound, the intensity of which was estimated by measuring the absorbance at
535 nm in a Pye Unicam PU 8650 visible spectrophotometer.
The concentration of mimosine was then calculated from a standard curve using pure mimosine (Sigma Chem. Co., Ltd., London),
Statistical analyses of the results of the feeding trial were made by using
analysis of variance (ANOVA). Duncan’s Multiple Range Test (Duncan, 1955)
was used to evaluate the mean differences among individual diets at the 0.05
significance level. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
RESULTS
Mimosine was not detected in the soaked leaf meal whereas the sundried
and commercial leaf meal contained 3% and 1.8% mimosine, respectively.
However, the mimosine contents of the experimental
diets were lower than the
calculated values, particularly
in those diets containing 100% plant protein,
with only zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
1.61% and 0.72% for sundried and commercial
leaf meal feeds,
respectively
(Table 2). As mimosine is prone to degradation
even under mild
conditions of drying (Hegarty et al., 1964a), sundrying of the experimental
diets probably caused reduced levels of mimosine in the experimental
diets.
All fish soon became accustomed to the experimental diets and were observed
to feed aggressively throughout the duration of the experiment. Fish fed diet 6
(50% sundried zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Leucaena) and diet 5 (25% sundried Leucuena) had cataracts
after the fourth week and 10th week, respectively. A total of five fish fed diet
5 and 14 fish fed diet 6 had cataracts at the end of the experiment. There was
only a single mortality, in the tank fed diet 6 at the end of the experiment
(the
fish had cataracts).
Some of the female experimental fish fed diets 1 (control) and 2 (25% soaked
leaf) started breeding as early as the 28th day after the commencement
of the
experiment. By day 56 most of the females in tanks fed other diets also showed
breeding activities, except tanks fed diet 4 (100% soaked Leucaena), diet 6
102 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
800
0
K
( control 1
700
/ zyxwvutsrqponmlkjihgfedcbaZYXW
600
23 % ( soaked 1
3
500
r
a
;
0
400
/
//
:
25 % ( commwcial
//50’%(
1
#oaked 1
5
2
300
25 X ( sundrlrd
1
%
200
50 74 ( commrrcial )
50 % ( rundrhd
100
)
100 X ( soaked )
100 % ( rundried )
100 % ( commercial 1
0
14
28
42
TIME
56
70
( days 1 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM
Fig. 1. The effects of different levels of Leucaena leaf meal on percent weight gain of Oreochromis
niloticus (figures indicate percent protein from the Leucaena leaf meal).
(50% sundried Leucaenu) , diet 7 (100% sundried Leucuena) and diet 10 (100%
commercial zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Leucaena) .
The growth responses of fish fed the experimental diets are shown in Figs.
1 and 2 and Table 3. There was a trend of reduced growth performance with
increase in the zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Ieve of Leucuenu leaf meal, irrespective of the type of leaf meal,
on the basis of daily weight gain, percentage weight gain and specific growth
rate. In general, there were no significant differences in growth responses for
fish fed 25% or 50% plant protein for the soaked or commercial leaf meal,
103
zyxwvutsrq
5.0
t
0
4.0
;;
K
a
ontrol
( no leuco*na 1
3.0
z
0
0
LL
2.0
[
1.0
soaked
sundried
commwcbl
a
0
25
LEVELS
1
so
OF DIETARY PROTEIN
I
75
FROM LEUCAENA
1
100
LEAF MEAL
( % )
zyxwvutsrqponmlkjihgfed
Fig. 2. Relationship between specific growth rate of zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQ
Oreochromis niloticus and levels of dietary
protein from Leucaena leaf meal. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE
respectively, but they were significantly better than those which were fed 100%
plant protein. In contrast, with the sundried leaf meal, the growth responses
between the 50% and 100% plant protein diets were not significantly different
but were significantly lower than the 25% diet. Diets containing soaked leaf
meal generally performed better than diets incorporating the sundried commercial leaf meal at all levels of inclusion, although at 25% plant protein, the
differences were not statistically significant. The nutritive value of sundried
leaf meal was only slightly higher than that of the commercial leaf meal. When
compared to the control diet (diet 1, 100% protein from fish meal), only the
growth response of fish fed diet 2, containing 25% plant protein, using soaked zyxwvutsrqpon
Leucaena leaf meal, was comparable.
The mean values of feed utilization efficiencies of fish fed the experimental
diets are shown in Table 4. Trends similar to those found for the growth
responses were observed with regards to the different leaf meal treatments and
varying levels of the leaf meal incorporated. Hence, feed utilization efficiencies
were reduced with an increase in the percentage of leaf meal used irrespective
104
TABLE 3
Growth performance
of fish fed experimental
diets for 70 days’
Diets
Mean values
1
Initial weight
(PI
Final weight
(9)
Daily weight
gain
(g/day I
Percentage
weight
gain (W)
Specific
growth
rate
2
2.93”
3
2.96”
24.53”
19.65ah
0.31”
0.24’
5
4
6
I
8
9
2.70”
3.15”
3.12”
2.67”
2.94”
2.85”
12.64s
5.07’
12.65b
5.75
4.31’
0.03
0.14b
0.05’
0.02
0.14b
10
3.13
3.12”
14.00b
8.68&.
3.79c
0.16b
O.Ogbc
0.01”
736.66”
563.03””
367.16s
61.57d
305.81s
115.08’
46.32d
392.0Eb
183.14k
21.36d
3.03”
2.70sh
2.20”
0.6gd
2.00b
1.10
0.54d
2.27b
1.4gk
0.2gd
different
(P~0.05).
( %/day)
‘Figures in the same rows having the same superscript
are not significantly
of the type of leaf meal. Good food conversion ratios (FCR) were obtained for
the three treatments at the lower rate of inclusion levels of 25% and 50% plant
protein. However, at the 100% plant protein level, the FCR was substantially
poorer. The protein efficiency ratio (PER) and apparent net protein utilizaTABLE 4
Feed utilization
for 70 days’
efficiencies
and nutrient
digestibility
of 0. niloticus
fed different
levels of Leucaena
leaf meal
Diet
Mean values
1
Food conversion
ratio
Protein
efficiency
ratio
Apparent net
protein
utilization
Apparent
protein
digestibility
f%)
Total
digestibility
(W)
2
3
4
6
5
7
8
9
10
1.31”
1.46”
1.91s
6.29*
2.12s
4.09’
8.10d
1.74”s
2.6Ebc
15.24”
2.54”
2.30
1.80”
0.74’
1.56s
0.84’
0.57
1.90ab
1.40b
0.40’
8.56cd
5.8Ed
27.74b
19.25b
3.60d
40.718
36.58”
26.65b
11.26’
22.93”
88.34
74.86
65.22
41.00
72.35
65.63
40.00
64.97
49.03
35.14
50.56
51.14
46.43
44.30
50.54
45.78
43.03
45.68
36.11
28.57
‘Figures in the same rows having the same superscripts
are not significantly
different
(P~0.05).
105
TABLE 5
Gross body composition of experimental fish at the beginning and end of the experiment (values are expressed
as %, wet weight basis 1’
Initial Diet
1
2
3
4
5
6
7
8
9
10
79.76 76.12” 76.32” 77.73b 78.42& 77.6@
81.11’ 79.81’ 77.73h 78.4gbc 79.87’
Moisture
Crude protein
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
13.97 15.79” 15.61” 14.62b 14.45b 14.55b 11.97’ 12.82’ 14.48b 13.80k 13.08
Crude lipid
2.44
3.70”
3.54”
3.0P
2.41b
3.04”b
2.19
2.04’
3.12sb
2.60b
2.06’
4.01
Ash
4.15”
4.07”
4.11”
4.72b
3.98”
4.55’
4.72”
3.94”
4.09
4.80”
‘Figures in the same rows having the same superscript are not significantly different (Pi 0.05).
tion (NPU) also showed such a relationship,
i.e., within each treatment the
PER and NPU values were significantly reduced with an increase in the level
of leaf meal incorporation
for all treatments.
With respect to the effects of the
different treatments
on the feed utilization efficiencies, at the 25% and 50%
inclusion levels soaked leaf meal gave the best FCR, PER and NPU, followed
by sundried and commercial leaf meal but the values obtained with the latter
two treatments
were not significantly different.
An increase in the level of plant protein, regardless of treatment, resulted in
a significant reduction in apparent protein digestibility ( APD ) (Table 4). The
APD values obtained with the soaked and sundried leaf meal were comparable
and better than those obtained with commercial leaf meal. This was presumably because commercial leaf meal also includes the stems whilst the soaked
and sundried leaf meals contained
only leaves. Total digestibility
values
reflected those of APD.
The carcass composition of experimental
fish at the beginning and end of
the experiment is shown in Table 5. An increase in the level of zyxwvutsrqponmlkjihgfedcb
Leucaena leaf
meal inclusion resulted in a significant decrease in carcass protein and fat
contents and an increase in carcass moisture and ash content in all treatments.
At the low level of incorporation
of 25% plant protein, the carcass composition
was not significantly different for fish fed the differently treated leaf meals. At
the higher percentages of 50% and 100% leaf meal, feeding with soaked leaf
meal generally resulted in a better condition of fish in terms of higher carcass
protein and fat content and lower moisture and ash content than with sundried
or commercial leaf meals.
DISCUSSION
The nutritive value of suitably processed Leucaena leaf meal as an alternative protein source was demonstrated
in this study. It was possible to include
soaked leaf meal (submerged in water for 48 h and sundried) up to 25% of the
total protein with no adverse effects on the growth of the fish. The growth
106
performances
and feed utilization efficiencies of fish fed diets containing the
soaked zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Leucaena leaf meal were better than those fed commercial and sundried
leaf meal, with little difference between the latter two, at each level of inclusion. This can best be explained from the mimosine content of the diet; those
containing sundried and commercial leaf meals had from 0.51.6% mimosine.
The subacute levels of mimosine present in these two diets could have led to
the poorer growth responses and feed conversion efficiencies. Furthermore,
an
increase in the levels of leaf meal incorporation
led to increases in dietary
mimosine concentration
and subsequent consumption,
and consequently even
poorer growth performances,
particularly
those diets containing 100% plant
protein which provided only 21% dietary protein.
The results obtained in the present study support the work of Ter Meulen
and El-Harith (1983) on carp ( Cyprinus carpio) fed increasing levels of mimosine extracted from Leucaena leucocephala. They found that fish fed 2%, 4%,
and 6% mimosine in a basal diet showed progressively poorer growth performances and PER. At the highest level (6% ) , half the number of experimental
fish died within the first week, and no growth was observed after 4-5 weeks for
the lower levels (2% and 4% ) of mimosine incorporation.
It was concluded
that a mimosine intake rate of 0.20 g mimosine kg-’ day-’ is harmful for carp.
In the present study, fish fed 100% Leucaena leaf meal, both the sundried and
commercial leaf meal, showed poor growth responses, probably because of the
high mimosine content. Jackson et al. (1982) obtained a similar poor growth
response with tilapia (Tilapia mossambicus) fed Leucaena leaf meal (autoclaved at 1.05 kg/cm2 for 40 min) contributing
25%, 50%, and 60% of the total
protein. In contrast, Pantastico and Baldia (1979) reported that the growth
responses of T. mossambica fed with Leucaena leaf meal (dried) alone at
increasing percentages of 3%, 6% and 9% body weight, improved with increasing amounts of leaf meal. In another study with Tilapia nilotica in cages, Pantastico and Baldia (1980) found that increasing the Leucaena leaf meal
concentration
in supplementary
diets (33.3%, 66.7% and 100% leaf meal balanced by rice bran) improved the growth responses, with the diet containing
100% Leucaena leading to the best weight gain although there were no statistically significant growth response differences between the three diets.
The toxic effects of mimosine to other animals have been well documented.
For instance, sheep fed Leucaena seed meal or mimosine itself demonstrated
poor growth, shedding of fleeces and eventual death (Hegarty et al., 1964b).
Other investigations
suggested that mimosine caused infertility
(Hylin and
Lichton, 1965)) loss of hair, decreased weight gain and cataracts
(Yoshida,
1944) in rats and inhibited general metal-containing enzymes
(Lin et al., 1963).
Toxic effects of mimosine on the health of fish, however, have not been reported.
Hence, the occurrence of cataracts in the experimental
fish fed certain diets
containing mimosine is of interest. Ter Meulen and El-Harith
(1983 ) fed fish
even higher values of mimosine than those used in the present study and
107
although they showed a poor growth response and acute toxicity, cataracts or
other pathological symptoms were not reported. Pantastico and Baldia (1979,
1980) and Ghatnekar et al. (1982) reported no adverse effects on the growth
or reproductive behaviour of fish. In this context it is also interesting to note
that spawning activity of 0. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE
niloticus fed low levels of mimosine occurred but
it was suppressed at high intake levels in the present study.
The efficacy of the two processing techniques used in the present study in
removing mimosine was evident from the subsequent
growth responses
obtained. Soaking in water for 48 h completely degraded the mimosine to DHP
whilst sundrying partially eliminated it. Camacho and Dureza (1977)) however, found no significant differences in growth, feed conversion efficiencies,
and survival rates of zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
T. mossambica fed pelletized Leucaena leaf meal treated
as follows: sundried dried leaf meal; heated to 80°C for 2 h and dried, treated
with ferrous sulphate solution for 1 week and dried. The amount of mimosine
present in each of the treatments
was unfortunately
not provided. However,
the conversion of mimosine to DHP may not remove the antinutrition
problem; although DHP is relatively nontoxic, it may exert chronic effects as it has
been shown to be goitrogenic for some animals, particularly monogastrics, which
do not possess the necessary gut flora to degrade the DHP further to non-toxic
compounds (Lowry, 1982). However, despite the fact that mimosine can be
completely or partially eliminated, the nutritive value of the processed leaf
meal appears to be limited by other nutritional
factors, such as the lack of
certain essential amino acids. It is not possible to replace more than 25-50%
of the total protein with mimosine-free
Leucuenu leaf meal without adversely
affecting the growth and body composition.
ACKNOW LEDGEM ENTS
The authors thank Ms. Chintana Pacharaprakiti
for technical assistance.
S.S. Wang was supported by a scholarship from the Canadian International
Development Agency (CIDA) to study for the degree of Master of Science at
the Asian Institute of Technology. Dr. Peter Edwards, seconded by the Overseas Development
Administration
to the Asian Institute of Technology,
is
thanked for a critical review of the manuscript.
REFERENCES
Association of Official Analytical Chemists ( AOAC
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONML
) , 1984. Official M ethods of Analysis of the
Association of Official Analytical Chemists, 13th edition. Edited by S. W illiams. Association
of Official Analytical Chemists Inc., Arlington, VA. 1141 pp.
Camacho, A.S. and Dureza, L.D., 1977. Feeding trial using treated and untreated ipil-ipil (Leu- zyxwvutsrqp
caena leucocephala) leaf meal in pelletized feed for Tilapia. Inland Fish Proj. Tech. Rep. Nos.
11-12, pp. 87-89.
108
Duncan, D.B., 1955. Multiple range and multiple F-sets. Biometrics, 11: l-42.
Furukawa, A. and Tsukahara, H., 1966. On the acid digestion method for the determination
of
chromic oxide as an index substance in the study of digestibility of fish feeds. Bull. Jpn. Sot.
Sci. Fish., 32 (6): 502-506.
Ghatnekar, SD., Auti, D.G. and Kamat, V.S., 1982. Feeding Leucaena to Mozambique tilapia and
Indian major carps. Proceedings of a Workshop on zyxwvutsrqponmlkjihgfedcbaZYXWVUTSR
Leucaena Research in the Asian-Pacific
Region in Singapore, 23-26 Nov. 1982, IDRC2lle,
pp. 61-63.
Hegarty, M.P., Court, R.D. and Thorne, P.M., 1964a. The determination
of mimosine and 3,4dihydroxypyridine
in biological material. Aust. J. Agric. Res., 15: 160-179.
Hegarty, M.P., Schinckel, P.G. and Court, R.D., 196413.Reaction of sheep to the consumption of
Leucaenaglauca
Benth. and to its toxic principle mimosine. Aust. J. Agric. Res., 15: 153-167.
Hylin, J.W. and Lichton, LJ., 1965. Production of reversible infertility in rata by feeding mimosine. Biochem. Pharmacol., 14: 1167-1168.
Jackson, A.J., Capper, B.S. and Matty, A.J., 1982. Evaluation of some plant proteins in complete
diets for the tilapia Sarotherodon mossambicus. Aquaculture, 27: 97-109.
Lin, J.Y., Kuang, T.L. and Ling, K.H., 1963. Studies on the mechanism of toxicity of mimosine
III. The effect of mimosine on the activity of L-Dopa decarboxylase, in vitro. J. Formosan
Med. Assoc., 62: 587-592.
Lowry, J.B., 1982. Detoxification
of Leucaena by enzymic or microbial processes. Proceedings of
a Workshop on Leucaena Research in the Asian-Pacific
Region in Singapore, 23-26 Nov. 1982,
IDRC-2lle, pp. 49-54.
Matsumoto, H. and Sherman, G.D., 1951. A rapid calorimetric method for the determination
of
mimosine. Arch. Biochem. Biophys., 33: 195-200.
Pantastico, J.B. and Baldia, J.P., 1979. Supplemental zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM
feeding zyxwvutsrqponmlkjihgfedcbaZYXWV
of Tilapia mossambica. In: K. Tiews
and J. HaIver (Editors), Proc. World Symp. on Finfish Nutrition and Fishfeed Technology.
Heenemann, Berlin, Vol. 1, pp. 587-593.
Pantastico, J.B. and Baldia, J.P., 1980. Ipil-ipil leaf meal as supplement feed for 2’. nilotica in
cages. Fish. Res. J. Philipp., 5 (2) : 63-68.
Tacon, A.G.J., 1981. The possible substitution
of fish meal in fish diets. In: Proceedings of the
SMBA/HIDB Fish Farming Meeting, 26-27 February 1981, Oban, Great Britain, pp. 46-56.
Ter Meulen, U. and El-Harith, E.A., 1983. Effects of oral administration
of 8-N (3-hydroxy-4pyridone) -o-amino propionic acid (mimosine)
in carps (Cyprinus carpio zyxwvutsrqponmlkjihgfedc
L. ) . Tropenlandwirt, Z. Landwirtschaft
in den Tropen und Subtropen, 84: 29-37.
Wee, K.L. and Ng, L.T., 1986. Use of cassava as an energy source in a pelleted feed for the tilapia,
Oreochromis niloticus L. Aquaculture Fish. Manage., 17 (2): 124-138.
Yoshida, R.K., 1944. A chemical and physiological study of the nature and properties of the toxic
principles of Leucaena glauca. Ph.D. thesis, University of Minnesota, Minneapolis.
Elsevier Science Publishers
97
B.V., Amsterdam
-
Printed
in The Netherlands zyxwvutsrqponmlkjihgfedc
Nutritive Value of Leucaena Leaf Meal in Pelleted
Feed for Nile Tilapia
KOK LEONG WEE and SHU-SEN
WANG’
Division zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
of zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Agricultural and Food Engineering, Asian Institute of Technology, G.P.O. Box 2754,
Bangkok 10501 (Thailand)
‘Present address: Shijiazhuang
(People’s Republic of China)
(Accepted
19 September
Institute
of Agricultural
Modernization,
P.O. Box 185, Hubei
1986)
ABSTRACT
Wee, K.L. and Wang, S.-S., 1987. Nutritive
tilapia. Aquaculture, 62: 97-108.
value of Leucaena
leaf meal in pelleted feed for Nile
An experiment was conducted to determine the suitability of treated Leucaena leucocephala
leaf meal as an ingredient for Nile tilapia, Oreochromis niloticus Linn., feed. Nine experimental
diets were formulated to contain 25%, 50% and 100% of the total dietary protein as plant protein
using soaked (soaked in water at 30 oC for 48 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK
h ) , sundried (sundried for 2 days) and commercial
Leucaena leaf meal, balanced by protein from fish meal. A control diet with fish meal as the only
protein source was included. All diets were isonitrogenous
(30% protein) except for diets containing 100% plant protein (21% protein). The 70&y feeding trial was conducted with duplicated treatments
in 2-m3 circular concrete tanks with recirculating water. There was a trend of
reduced growth performance and feed utilization efficiency with increase in Lezuxena leaf meal
incorporation
for all treatments.
Generally, soaked leaf meal gave a significantly better growth
response than sundried or commercial leaf meal. Mimosine present in the latter two treatments
may have contributed to the poorer growth.
INTRODUCTION zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
The increasing cost of fish feed has focused research on reducing the cost of
the most expensive item, the protein source. Numerous works have been
reported on the possible replacement of fish meal which is used at a high level
in most fish feeds (Tacon, 1981: Jackson et al., 1982). Leaf meal from LRucaena zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
leucocephatu is a potential source of protein. It is a vigorous and droughtresistant leguminous tree whose high-protein leaves have been widely used in
animal feeds, particularly for ruminants in the tropics. However, the presence
of the toxic amino acid, mimosine, has limited its use. Published evidence on
the nutritive value of lkucaena leaf meal to fish is conflicting. Pantastico and
0044- 8486/87/$03.50
0 1987 Elsevier
Science Publishers
B.V.
TABLE 1
Composition
of experimental
diets (g/l00 g)
Leucaena
Diet
leaf meal
Control
Soaked
1
2
Commercial
Sundried
3
4
5
6
7
8
100.0
25.0
Plant protein as % of
0.0
25.0
50.0
50.0
100.0
25.0
total protein zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
44.0
lkumena leaf meal
31.0
61.0
90.0
61.0
90.0
31.0
Fish meal
24.0
37.0
50.0
37.0
24.0
37.0
3.1
4.2
4.7
3.6
Fish oil (freshwater
3.6
4.2
4.8
3.6
fish)
Corn oil
4.1
5.0
3.7
2.4
3.7
2.5
1.3
1.2
7.3
30.0
20.7
4.4
Cassava starch
20.7
4.3
Binder’
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.0
1.0
Vitamin premix’
1.0
1.0
1.0
1.0
1.0
1.0
Mineral premix3
1.0
1.0
1.0
1.0
2.0
2.0
1.0
1.0
Chromic oxide
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
7.9
cr-Cellulose
9
10
50.0
100.0
66.7 zyxwvutsrqponmlkjihgfedcb
90.0
20.0
4.0
4.0
3.6
1.7
1.5
1.0
2.0
0.5
-
2.0
1.5
1.0
2.0
0.5
-
‘Carboxymethyl cellulose.
‘To supply/l00 g diet: thiamine (Bl), 2.5 mg; riboflavin (B2), 2.5 mg; pyridoxine (B6), 2.0 mg; pantothenic acid, 5.0 mg; inositol, 100 mg; biotin,
0.3 mg; folic acid, 0.75 mg; para-aminobenzoic
acid, 2.5 mg; choline, 200 mg; niacin (B3), 10.0 mg; cyanocobalamin
(B12), 0.005 mg; retinol
palmitate (A), 100 000 IU; cr-tocopherol acetate (E) ,20.1 mg; ascorbic acid zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
(C) zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
,50.0 mg; menadione zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLK
(K),2.0 mg; cholecalciterol (D3), 500 000
IU.
3To supply/l00 g diet: CaHP04.H20,727.78
mg; MgS0.,.7Hz0,127.5
mg; NaCl, 60.0 mg; KCl, 50.0 mg; FeS0,.7H,O,
25.0 mg; ZnS04.7Hz0, 5.5 mg;
MnS0,.4Hz0,
2.5 mg; CuS04.5H,0, 0.79 mg; CoS0,7H,O,
0.48 mg; CaI03.6H,0, 0.3 mg; CrCl,.6H20, 0.13 mg.
99
Baldia (1979, 1980) and Ghatnekar
et al. (1982) reported improved growth
performances
of tilapia species with the inclusion of zyxwvutsrqponmlkjihgfedcbaZYXWVU
Leucaena leaf meal in the
diet. However, Jackson et al. (1982) found that Leucuenu leaf meal as a 25%
replacement of fish meal in a diet for tilapia supported poor growth, which was
attributed to possible toxic effects of mimosine. However, mimosine can be
degraded to a relatively less toxic form, 3-hydroxy-4 (III) -pyridone (DHP ) ,
through various methods of processing, thereby improving the nutritive value
of Leucaena leaf meal. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
MATERIALS AND METHODS
Diets
Ground fish meal and test Leucuenu leaf meal (passed through a 593qm
mesh sieve) were used as dietary protein sources in diets supplemented
with
corn oil, freshwater fish oil, and cassava starch. Three test Leucuenu leaf meals
were used: soaked leaf meal (leaves from a local Thai Leucaenu leucocephula
strain grown on the Asian Institute of Technology campus were submerged in
tap water at an ambient temperature
of 30°C for 48 h and sundried for 12 h) ;
sundried leaf meal ( leaves were sundried for 2 days), and commercial leaf meal
(sundried leaves and stems). The efficacy of these treatments was determined
by measuring the mimosine content of the leaves before and after processing.
Ten experimental
diets were formulated to contain varying ratios of plant to
animal proteins - 25:75, 50:50 and 100:O.
Diet 1 with 100% fish meal protein served as a control, and diets 2,3 and 4;
5, 6 and 7; and 8, 9 and 10 contained soaked, sundried and commercial leaf
meal which contributed 25%, 50% or 100% of the total dietary protein, respectively ( Table 1) . The diets were isonitrogenous
(30% crude protein) and isocaloric (360 kcal/lOO g diet) except diets 4, 7 and 10 (21% crude protein)
(Table 2). The diets were prepared as described previously (Wee and Ng, 1986 ) .
Experimental systems and animals
The feeding trial was conducted in 20 circular concrete tanks of 1.25 m diameter and 0.60 m depth of water, located outdoors under a thatch roof. The water
was recirculated after passing through a mechanical and biological filter. Each
tank was continuously
supplied with freshwater at a mean rate of 7 l/min.
Water temperature,
dissolved oxygen, total ammonia, nitrite and pH were
monitored at Z-week intervals and varied from 26.5-27.O”C, 7.7-8.2 mg/l,
0.6-1.7 pg/l, 0.2 pg/l and 7.9-8.8, respectively. Algal growth, measured as chlorophyll-a, was not detected in any of the experimental
tanks.
Oreochromis niloticus fingerlings (mean weight 3.0 g) were obtained from a
commercial dealer, and acclimatized in the tanks for 2 weeks while fed with
100
TABLE 2
Proximate composition of experimental diets (all values are expressed as %, dry weight basis)
Component
Moisture
Crude protein
Crude lipid
Crude fihre
Ash
NFE’
Mimosine’
Gross energy3
Metabolizable
energy’
Dieta
Control
Soaked Leucaena leaf
meal
Sundried Leucaena leaf
meal
Commercial Leucaena
leaf meal
1
2
3
4
5
6
7
8
9
10
9.6
30.1
10.0
0.92
25.6
12.7
0.00
369.0
291.7
5.0
29.7
10.0
7.3
27.8
11.3
0.00
375.5
294.1
4.9
29.0
10.1
13.2
23.7
9.7
0.00
356.0
283.3
5.3
21.5
9.9
19.2
29.3
5.9
0.00
334.2
255.2
6.2
29.8
10.0
7.0
27.4
11.2
0.71
374.4
293.8
5.4
29.2
10.1
12.9
22.8
9.4
1.34
353.6
282.5
6.0
21.7
9.8
18.7
28.2
5.5
1.61
329.6
253.1
4.9
30.3
10.0
8.8
23.1
12.0
0.48
360.1
287.7
8.8
26.6
9.8
13.1
26.1
9.5
0.66
352.3
275.0
4.6
16.3
7.9
17.0
34.3
6.5
0.72
305.1
221.2
‘NFE: Nitrogen-free extracts = 100 -moisture - crude protein - crude lipid - zyxwvutsrqponmlkjihgfedcbaZYXW
crude fibre -ash.
‘Average values obtained with two eamples each having two replicate determinations.
“Gross energy: in kcal/lOO g, based on 5.7 kcal/g protein; 9.5 kcal/lOO g lipid; 4.0 kcal/g carbohydrate.
‘Metabolixable energy: in kcal/lOO g, baaed on 5.0 kcal/g protein; 9.0 kcal/g lipid; 2.0 kcal/g carbohydrate. zyxwvutsrqponm
pelleted feed (30% crude protein) produced by the National Inland Fisheries
Institute, Bangkok. The fingerlings were randomly distributed between the
tanks at a stocking density of 10 fish/tank, with treatments in duplicate also
arranged at random. At the start of the feeding trial, 20 fish were sacrificed by
a sharp blow to the head, dried in the oven for moisture determination and
stored for subsequent carcass analysis. The experimental fish were weighed
individually at the beginning and end of the feeding trial, but batch weighing
was used at 2-week intervals for feeding rate calculation. Fish were fed twice
daily, 6 days a week, at a fixed feeding rate of 5% wet body weight (dry feed/
body weight) per day, with the feeding allowance adjusted accordingly at 2week intervals. The study was conducted for 10 weeks after which the experimental fish were sacrificed, and fish carcasses taken for gross chemical analysis. In the last week of the experiment, faeces were sampled overnight from
the experimental tanks. Faeces collected from replicate treatments were pooled,
dried in an oven, and stored for subsequent chemical analysis. zyxwvutsrqponmlkjihgfed
Analytical methods
Feed ingredients, experimental diets, and fish carcasses were analyzed for
their proximate composition by the following methods in triplicate: moisture,
determined by oven-drying at 85°C to constant weight; crude protein, determined indirectly from the analysis of total Kjeldahl nitrogen (crude pro-
101
tein=N ~6.25) by the Kjeldahl method [Association
of Official Analytical
Chemists ( AOAC ) , 19841; crude lipid, determined by extraction with diethyl
ether for 6 h in a soxhlet apparatus; ash, determined from weighed samples in
a porcelain crucible placed in a muffle furnace at 550°C for 4 h; fibre content
determined using acid-base digestion ( AOAC,
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM
1984).
For the apparent nutrient digestibility measurements,
chromic oxide was
determined in the faeces and diets using the method of Furukawa and Tsukahara (1966).
The mimosine content of the leaf meal and experimental
diets was determined by the rapid calorimetric method of Matsumoto and Sherman (1951).
To extract the mimosine, samples were digested with 0.1 N HCl, filtered and
clarified by removing plant pigments with activated carbon. Ferric chloride
(0.5% ) was then added to the mimosine extracts to develop a coloured compound, the intensity of which was estimated by measuring the absorbance at
535 nm in a Pye Unicam PU 8650 visible spectrophotometer.
The concentration of mimosine was then calculated from a standard curve using pure mimosine (Sigma Chem. Co., Ltd., London),
Statistical analyses of the results of the feeding trial were made by using
analysis of variance (ANOVA). Duncan’s Multiple Range Test (Duncan, 1955)
was used to evaluate the mean differences among individual diets at the 0.05
significance level. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
RESULTS
Mimosine was not detected in the soaked leaf meal whereas the sundried
and commercial leaf meal contained 3% and 1.8% mimosine, respectively.
However, the mimosine contents of the experimental
diets were lower than the
calculated values, particularly
in those diets containing 100% plant protein,
with only zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
1.61% and 0.72% for sundried and commercial
leaf meal feeds,
respectively
(Table 2). As mimosine is prone to degradation
even under mild
conditions of drying (Hegarty et al., 1964a), sundrying of the experimental
diets probably caused reduced levels of mimosine in the experimental
diets.
All fish soon became accustomed to the experimental diets and were observed
to feed aggressively throughout the duration of the experiment. Fish fed diet 6
(50% sundried zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Leucaena) and diet 5 (25% sundried Leucuena) had cataracts
after the fourth week and 10th week, respectively. A total of five fish fed diet
5 and 14 fish fed diet 6 had cataracts at the end of the experiment. There was
only a single mortality, in the tank fed diet 6 at the end of the experiment
(the
fish had cataracts).
Some of the female experimental fish fed diets 1 (control) and 2 (25% soaked
leaf) started breeding as early as the 28th day after the commencement
of the
experiment. By day 56 most of the females in tanks fed other diets also showed
breeding activities, except tanks fed diet 4 (100% soaked Leucaena), diet 6
102 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
800
0
K
( control 1
700
/ zyxwvutsrqponmlkjihgfedcbaZYXW
600
23 % ( soaked 1
3
500
r
a
;
0
400
/
//
:
25 % ( commwcial
//50’%(
1
#oaked 1
5
2
300
25 X ( sundrlrd
1
%
200
50 74 ( commrrcial )
50 % ( rundrhd
100
)
100 X ( soaked )
100 % ( rundried )
100 % ( commercial 1
0
14
28
42
TIME
56
70
( days 1 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM
Fig. 1. The effects of different levels of Leucaena leaf meal on percent weight gain of Oreochromis
niloticus (figures indicate percent protein from the Leucaena leaf meal).
(50% sundried Leucaenu) , diet 7 (100% sundried Leucuena) and diet 10 (100%
commercial zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Leucaena) .
The growth responses of fish fed the experimental diets are shown in Figs.
1 and 2 and Table 3. There was a trend of reduced growth performance with
increase in the zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Ieve of Leucuenu leaf meal, irrespective of the type of leaf meal,
on the basis of daily weight gain, percentage weight gain and specific growth
rate. In general, there were no significant differences in growth responses for
fish fed 25% or 50% plant protein for the soaked or commercial leaf meal,
103
zyxwvutsrq
5.0
t
0
4.0
;;
K
a
ontrol
( no leuco*na 1
3.0
z
0
0
LL
2.0
[
1.0
soaked
sundried
commwcbl
a
0
25
LEVELS
1
so
OF DIETARY PROTEIN
I
75
FROM LEUCAENA
1
100
LEAF MEAL
( % )
zyxwvutsrqponmlkjihgfed
Fig. 2. Relationship between specific growth rate of zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQ
Oreochromis niloticus and levels of dietary
protein from Leucaena leaf meal. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE
respectively, but they were significantly better than those which were fed 100%
plant protein. In contrast, with the sundried leaf meal, the growth responses
between the 50% and 100% plant protein diets were not significantly different
but were significantly lower than the 25% diet. Diets containing soaked leaf
meal generally performed better than diets incorporating the sundried commercial leaf meal at all levels of inclusion, although at 25% plant protein, the
differences were not statistically significant. The nutritive value of sundried
leaf meal was only slightly higher than that of the commercial leaf meal. When
compared to the control diet (diet 1, 100% protein from fish meal), only the
growth response of fish fed diet 2, containing 25% plant protein, using soaked zyxwvutsrqpon
Leucaena leaf meal, was comparable.
The mean values of feed utilization efficiencies of fish fed the experimental
diets are shown in Table 4. Trends similar to those found for the growth
responses were observed with regards to the different leaf meal treatments and
varying levels of the leaf meal incorporated. Hence, feed utilization efficiencies
were reduced with an increase in the percentage of leaf meal used irrespective
104
TABLE 3
Growth performance
of fish fed experimental
diets for 70 days’
Diets
Mean values
1
Initial weight
(PI
Final weight
(9)
Daily weight
gain
(g/day I
Percentage
weight
gain (W)
Specific
growth
rate
2
2.93”
3
2.96”
24.53”
19.65ah
0.31”
0.24’
5
4
6
I
8
9
2.70”
3.15”
3.12”
2.67”
2.94”
2.85”
12.64s
5.07’
12.65b
5.75
4.31’
0.03
0.14b
0.05’
0.02
0.14b
10
3.13
3.12”
14.00b
8.68&.
3.79c
0.16b
O.Ogbc
0.01”
736.66”
563.03””
367.16s
61.57d
305.81s
115.08’
46.32d
392.0Eb
183.14k
21.36d
3.03”
2.70sh
2.20”
0.6gd
2.00b
1.10
0.54d
2.27b
1.4gk
0.2gd
different
(P~0.05).
( %/day)
‘Figures in the same rows having the same superscript
are not significantly
of the type of leaf meal. Good food conversion ratios (FCR) were obtained for
the three treatments at the lower rate of inclusion levels of 25% and 50% plant
protein. However, at the 100% plant protein level, the FCR was substantially
poorer. The protein efficiency ratio (PER) and apparent net protein utilizaTABLE 4
Feed utilization
for 70 days’
efficiencies
and nutrient
digestibility
of 0. niloticus
fed different
levels of Leucaena
leaf meal
Diet
Mean values
1
Food conversion
ratio
Protein
efficiency
ratio
Apparent net
protein
utilization
Apparent
protein
digestibility
f%)
Total
digestibility
(W)
2
3
4
6
5
7
8
9
10
1.31”
1.46”
1.91s
6.29*
2.12s
4.09’
8.10d
1.74”s
2.6Ebc
15.24”
2.54”
2.30
1.80”
0.74’
1.56s
0.84’
0.57
1.90ab
1.40b
0.40’
8.56cd
5.8Ed
27.74b
19.25b
3.60d
40.718
36.58”
26.65b
11.26’
22.93”
88.34
74.86
65.22
41.00
72.35
65.63
40.00
64.97
49.03
35.14
50.56
51.14
46.43
44.30
50.54
45.78
43.03
45.68
36.11
28.57
‘Figures in the same rows having the same superscripts
are not significantly
different
(P~0.05).
105
TABLE 5
Gross body composition of experimental fish at the beginning and end of the experiment (values are expressed
as %, wet weight basis 1’
Initial Diet
1
2
3
4
5
6
7
8
9
10
79.76 76.12” 76.32” 77.73b 78.42& 77.6@
81.11’ 79.81’ 77.73h 78.4gbc 79.87’
Moisture
Crude protein
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
13.97 15.79” 15.61” 14.62b 14.45b 14.55b 11.97’ 12.82’ 14.48b 13.80k 13.08
Crude lipid
2.44
3.70”
3.54”
3.0P
2.41b
3.04”b
2.19
2.04’
3.12sb
2.60b
2.06’
4.01
Ash
4.15”
4.07”
4.11”
4.72b
3.98”
4.55’
4.72”
3.94”
4.09
4.80”
‘Figures in the same rows having the same superscript are not significantly different (Pi 0.05).
tion (NPU) also showed such a relationship,
i.e., within each treatment the
PER and NPU values were significantly reduced with an increase in the level
of leaf meal incorporation
for all treatments.
With respect to the effects of the
different treatments
on the feed utilization efficiencies, at the 25% and 50%
inclusion levels soaked leaf meal gave the best FCR, PER and NPU, followed
by sundried and commercial leaf meal but the values obtained with the latter
two treatments
were not significantly different.
An increase in the level of plant protein, regardless of treatment, resulted in
a significant reduction in apparent protein digestibility ( APD ) (Table 4). The
APD values obtained with the soaked and sundried leaf meal were comparable
and better than those obtained with commercial leaf meal. This was presumably because commercial leaf meal also includes the stems whilst the soaked
and sundried leaf meals contained
only leaves. Total digestibility
values
reflected those of APD.
The carcass composition of experimental
fish at the beginning and end of
the experiment is shown in Table 5. An increase in the level of zyxwvutsrqponmlkjihgfedcb
Leucaena leaf
meal inclusion resulted in a significant decrease in carcass protein and fat
contents and an increase in carcass moisture and ash content in all treatments.
At the low level of incorporation
of 25% plant protein, the carcass composition
was not significantly different for fish fed the differently treated leaf meals. At
the higher percentages of 50% and 100% leaf meal, feeding with soaked leaf
meal generally resulted in a better condition of fish in terms of higher carcass
protein and fat content and lower moisture and ash content than with sundried
or commercial leaf meals.
DISCUSSION
The nutritive value of suitably processed Leucaena leaf meal as an alternative protein source was demonstrated
in this study. It was possible to include
soaked leaf meal (submerged in water for 48 h and sundried) up to 25% of the
total protein with no adverse effects on the growth of the fish. The growth
106
performances
and feed utilization efficiencies of fish fed diets containing the
soaked zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
Leucaena leaf meal were better than those fed commercial and sundried
leaf meal, with little difference between the latter two, at each level of inclusion. This can best be explained from the mimosine content of the diet; those
containing sundried and commercial leaf meals had from 0.51.6% mimosine.
The subacute levels of mimosine present in these two diets could have led to
the poorer growth responses and feed conversion efficiencies. Furthermore,
an
increase in the levels of leaf meal incorporation
led to increases in dietary
mimosine concentration
and subsequent consumption,
and consequently even
poorer growth performances,
particularly
those diets containing 100% plant
protein which provided only 21% dietary protein.
The results obtained in the present study support the work of Ter Meulen
and El-Harith (1983) on carp ( Cyprinus carpio) fed increasing levels of mimosine extracted from Leucaena leucocephala. They found that fish fed 2%, 4%,
and 6% mimosine in a basal diet showed progressively poorer growth performances and PER. At the highest level (6% ) , half the number of experimental
fish died within the first week, and no growth was observed after 4-5 weeks for
the lower levels (2% and 4% ) of mimosine incorporation.
It was concluded
that a mimosine intake rate of 0.20 g mimosine kg-’ day-’ is harmful for carp.
In the present study, fish fed 100% Leucaena leaf meal, both the sundried and
commercial leaf meal, showed poor growth responses, probably because of the
high mimosine content. Jackson et al. (1982) obtained a similar poor growth
response with tilapia (Tilapia mossambicus) fed Leucaena leaf meal (autoclaved at 1.05 kg/cm2 for 40 min) contributing
25%, 50%, and 60% of the total
protein. In contrast, Pantastico and Baldia (1979) reported that the growth
responses of T. mossambica fed with Leucaena leaf meal (dried) alone at
increasing percentages of 3%, 6% and 9% body weight, improved with increasing amounts of leaf meal. In another study with Tilapia nilotica in cages, Pantastico and Baldia (1980) found that increasing the Leucaena leaf meal
concentration
in supplementary
diets (33.3%, 66.7% and 100% leaf meal balanced by rice bran) improved the growth responses, with the diet containing
100% Leucaena leading to the best weight gain although there were no statistically significant growth response differences between the three diets.
The toxic effects of mimosine to other animals have been well documented.
For instance, sheep fed Leucaena seed meal or mimosine itself demonstrated
poor growth, shedding of fleeces and eventual death (Hegarty et al., 1964b).
Other investigations
suggested that mimosine caused infertility
(Hylin and
Lichton, 1965)) loss of hair, decreased weight gain and cataracts
(Yoshida,
1944) in rats and inhibited general metal-containing enzymes
(Lin et al., 1963).
Toxic effects of mimosine on the health of fish, however, have not been reported.
Hence, the occurrence of cataracts in the experimental
fish fed certain diets
containing mimosine is of interest. Ter Meulen and El-Harith
(1983 ) fed fish
even higher values of mimosine than those used in the present study and
107
although they showed a poor growth response and acute toxicity, cataracts or
other pathological symptoms were not reported. Pantastico and Baldia (1979,
1980) and Ghatnekar et al. (1982) reported no adverse effects on the growth
or reproductive behaviour of fish. In this context it is also interesting to note
that spawning activity of 0. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE
niloticus fed low levels of mimosine occurred but
it was suppressed at high intake levels in the present study.
The efficacy of the two processing techniques used in the present study in
removing mimosine was evident from the subsequent
growth responses
obtained. Soaking in water for 48 h completely degraded the mimosine to DHP
whilst sundrying partially eliminated it. Camacho and Dureza (1977)) however, found no significant differences in growth, feed conversion efficiencies,
and survival rates of zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
T. mossambica fed pelletized Leucaena leaf meal treated
as follows: sundried dried leaf meal; heated to 80°C for 2 h and dried, treated
with ferrous sulphate solution for 1 week and dried. The amount of mimosine
present in each of the treatments
was unfortunately
not provided. However,
the conversion of mimosine to DHP may not remove the antinutrition
problem; although DHP is relatively nontoxic, it may exert chronic effects as it has
been shown to be goitrogenic for some animals, particularly monogastrics, which
do not possess the necessary gut flora to degrade the DHP further to non-toxic
compounds (Lowry, 1982). However, despite the fact that mimosine can be
completely or partially eliminated, the nutritive value of the processed leaf
meal appears to be limited by other nutritional
factors, such as the lack of
certain essential amino acids. It is not possible to replace more than 25-50%
of the total protein with mimosine-free
Leucuenu leaf meal without adversely
affecting the growth and body composition.
ACKNOW LEDGEM ENTS
The authors thank Ms. Chintana Pacharaprakiti
for technical assistance.
S.S. Wang was supported by a scholarship from the Canadian International
Development Agency (CIDA) to study for the degree of Master of Science at
the Asian Institute of Technology. Dr. Peter Edwards, seconded by the Overseas Development
Administration
to the Asian Institute of Technology,
is
thanked for a critical review of the manuscript.
REFERENCES
Association of Official Analytical Chemists ( AOAC
zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONML
) , 1984. Official M ethods of Analysis of the
Association of Official Analytical Chemists, 13th edition. Edited by S. W illiams. Association
of Official Analytical Chemists Inc., Arlington, VA. 1141 pp.
Camacho, A.S. and Dureza, L.D., 1977. Feeding trial using treated and untreated ipil-ipil (Leu- zyxwvutsrqp
caena leucocephala) leaf meal in pelletized feed for Tilapia. Inland Fish Proj. Tech. Rep. Nos.
11-12, pp. 87-89.
108
Duncan, D.B., 1955. Multiple range and multiple F-sets. Biometrics, 11: l-42.
Furukawa, A. and Tsukahara, H., 1966. On the acid digestion method for the determination
of
chromic oxide as an index substance in the study of digestibility of fish feeds. Bull. Jpn. Sot.
Sci. Fish., 32 (6): 502-506.
Ghatnekar, SD., Auti, D.G. and Kamat, V.S., 1982. Feeding Leucaena to Mozambique tilapia and
Indian major carps. Proceedings of a Workshop on zyxwvutsrqponmlkjihgfedcbaZYXWVUTSR
Leucaena Research in the Asian-Pacific
Region in Singapore, 23-26 Nov. 1982, IDRC2lle,
pp. 61-63.
Hegarty, M.P., Court, R.D. and Thorne, P.M., 1964a. The determination
of mimosine and 3,4dihydroxypyridine
in biological material. Aust. J. Agric. Res., 15: 160-179.
Hegarty, M.P., Schinckel, P.G. and Court, R.D., 196413.Reaction of sheep to the consumption of
Leucaenaglauca
Benth. and to its toxic principle mimosine. Aust. J. Agric. Res., 15: 153-167.
Hylin, J.W. and Lichton, LJ., 1965. Production of reversible infertility in rata by feeding mimosine. Biochem. Pharmacol., 14: 1167-1168.
Jackson, A.J., Capper, B.S. and Matty, A.J., 1982. Evaluation of some plant proteins in complete
diets for the tilapia Sarotherodon mossambicus. Aquaculture, 27: 97-109.
Lin, J.Y., Kuang, T.L. and Ling, K.H., 1963. Studies on the mechanism of toxicity of mimosine
III. The effect of mimosine on the activity of L-Dopa decarboxylase, in vitro. J. Formosan
Med. Assoc., 62: 587-592.
Lowry, J.B., 1982. Detoxification
of Leucaena by enzymic or microbial processes. Proceedings of
a Workshop on Leucaena Research in the Asian-Pacific
Region in Singapore, 23-26 Nov. 1982,
IDRC-2lle, pp. 49-54.
Matsumoto, H. and Sherman, G.D., 1951. A rapid calorimetric method for the determination
of
mimosine. Arch. Biochem. Biophys., 33: 195-200.
Pantastico, J.B. and Baldia, J.P., 1979. Supplemental zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM
feeding zyxwvutsrqponmlkjihgfedcbaZYXWV
of Tilapia mossambica. In: K. Tiews
and J. HaIver (Editors), Proc. World Symp. on Finfish Nutrition and Fishfeed Technology.
Heenemann, Berlin, Vol. 1, pp. 587-593.
Pantastico, J.B. and Baldia, J.P., 1980. Ipil-ipil leaf meal as supplement feed for 2’. nilotica in
cages. Fish. Res. J. Philipp., 5 (2) : 63-68.
Tacon, A.G.J., 1981. The possible substitution
of fish meal in fish diets. In: Proceedings of the
SMBA/HIDB Fish Farming Meeting, 26-27 February 1981, Oban, Great Britain, pp. 46-56.
Ter Meulen, U. and El-Harith, E.A., 1983. Effects of oral administration
of 8-N (3-hydroxy-4pyridone) -o-amino propionic acid (mimosine)
in carps (Cyprinus carpio zyxwvutsrqponmlkjihgfedc
L. ) . Tropenlandwirt, Z. Landwirtschaft
in den Tropen und Subtropen, 84: 29-37.
Wee, K.L. and Ng, L.T., 1986. Use of cassava as an energy source in a pelleted feed for the tilapia,
Oreochromis niloticus L. Aquaculture Fish. Manage., 17 (2): 124-138.
Yoshida, R.K., 1944. A chemical and physiological study of the nature and properties of the toxic
principles of Leucaena glauca. Ph.D. thesis, University of Minnesota, Minneapolis.