experimental diets to satiation twice per day, 6 days per week for 6 weeks. The fish were weighed every 2 weeks to follow the overall growth.
2.3. Sampling Ž
After the 6-week feeding trial, the fish were weighed and four fish from each tank 8 .
fishrtreatment were sampled and stored at y208C for subsequent analyses of the proximate and the amino acid composition of the whole body. The remaining fish were
fed their respective diets for another 2 days. In rainbow trout fed intact protein diets to Ž
. Ž
. satiation, Nose 1973 and Walton and Wilson 1986 reported that plasma FAA attained
maximum levels at 12 h after feeding and declined to the fasting levels by 48 h. By Ž
contrast, FAA in trout liver did not show distinct postprandial changes Walton and .
Wilson, 1986 . Thus, the fish in this study were then starved for 48 h, fed once again the diets to satiation, and blood and tissue samples for FAA analysis were collected at 12 h
Ž .
after the last feeding. Three fish from each tank 6 fishrtreatment were anesthetized in Ž
. 0.01 ethyl 3-aminobenzoate methanesulfonic acid Aldrich Chemical, USA . Blood
was immediately withdrawn from the caudal vein–artery complex and plasma samples for determination of FAA were prepared according to the procedures described in
Ž .
Yamamoto et al. 1998 . The fish were then placed into liquid nitrogen and stored at y808C for up to 1 week until extraction of FAA from tissues.
2.4. Analysis Proximate analysis of the diets and the whole bodies were carried out using the
Ž .
AOAC method slightly modified by Akiyama et al. 1984 . Amino acid composition of the protein sources and the whole bodies was determined after acid hydrolysis in 6 N
Ž .
HCl for 22 h at 1108C, as described in Yamamoto et al. 1997 . Cystine and tryptophan Ž
. in the protein sources were analyzed according to the methods of Moore 1963 and
Ž .
Penke et al. 1974 , respectively. The partially thawed–frozen fish were dissected and Ž
. whole brain and liver, and a portion of dorsal white muscle approximately 500 mg
were taken for FAA analysis. FAA in tissue samples were extracted with a perchloric Ž
. acid solution according to the method of Ogata and Murai 1994 . FAA levels were
Ž .
determined individually by an automatic amino acid analyzer L-8500 Hitachi, Japan Ž
. with a ninhydrin reagent and lithium buffer system Yamamoto et al., 1998 .
Ž .
Significance P - 0.05
of treatment means of growth performance parameters, whole body proximate and amino acid compositions, and tissue FAA levels, were
compared using one-way ANOVA followed by Duncan’s new multiple range test Ž
. Wakabayashi, 1984 .
3. Results
3.1. Growth and feed performance The results of the 6-week feeding trial are shown in Table 3. Percentage weight gain
Ž .
of the HPHF diet group was the highest, but was not different P 0.05 from the other
Table 3 Growth and feed performance of fingerling rainbow trout fed diets containing different levels of protein, fat
and amino acids
1 2
3
Diet LPLF
LPHF HPLF
HPHF IMB-HPLF
IMB-HPHF Pooled SEM
Ž . Initial mean weight g
9.6 9.5
9.5 9.5
9.5 9.5
0.18 Ž .
Final mean weight g 25.9
25.6 25.3
26.9 23.1
25.6 2.48
ab4 ab
ab b
a ab
Ž . Weight gain
171.0 168.9
165.9 183.1
142.6 169.4
9.87
a bc
d e
ab cd
Ž . Feed efficiency
99.6 115.1
129.3 147.2
109.4 125.1
3.00
b c
b b
a a
Ž . N retention
42.7 47.8
41.3 42.9
30.5 32.2
1.08
e d
b a
cd bc
Ž . Feed consumption
2.20 1.89
1.67 1.54
1.81 1.75
0.030 Ž .
Mortality
1
Average value of duplicate groups containing 30 fish each reared for 6 weeks at 158C.
2
LP; low protein with balanced amino acid diet, HP; high protein with balanced amino acid diet, IMB-HP; high protein with imbalanced amino acid diet, LF; low fat diet, HF; high fat diet.
3
Standard error of the means.
4
Ž .
Values in the same row with the same superscript are not different P 0.05 .
Ž .
treatment groups except for the IMB-HPLF diet group P - 0.05 . Feed efficiency was Ž
. higher P - 0.05 in the HF diet group than the LF group fed the same protein level or
amino acid profile diet. Although the feed efficiency of the IMB-HPLF group was Ž
. higher
P - 0.05 than the LPLF group, the efficiency of the IMB group was lower Ž
. P - 0.05 than the HP group fed the same fat level diet. Percentage dietary nitrogen
retained also showed a higher value in the HF group than in the LF group. Daily feed consumption rates were less in the high protein or fat diet groups. The feed consumption
Ž .
of the IMB group was higher P - 0.05 than the HP group fed the same fat level diet. 3.2. Whole body proximate and amino acid compositions
The proximate and the amino acid compositions of the whole body are shown in Ž
. Table 4. The protein content of the HPLF group was higher P - 0.05 , and that of the
Ž .
IMB-HPHF group was lower P - 0.05 , than the other groups. The HF diet group
Ž .
showed higher whole body fat level P - 0.05 than the LF diet group. The fat content Ž
. of the LP diet group was higher P - 0.05 than the HP diet group fed the same fat level
diet. Although differences in the levels of certain amino acids, such as histidine and
Ž .
glycine, in whole body protein were significant P - 0.05 among the dietary treat-
ments, the actual differences were small. 3.3. Plasma free amino acids
Levels of FAA and related compounds in plasma are shown in Table 5. Ž
. Increment of dietary protein level LPLF vs. HPLF, LPHF vs. HPHF increased
Ž .
P - 0.05 the levels of most EAA, and also of certain non-essential amino acids Ž
. NEAA such as asparagine and glycine. So the total EAA and the NEAA levels of the
Ž .
HP group were higher P - 0.05 than the LP group.
Table 4 Whole body proximate and amino acid compositions of rainbow trout fed diets containing different levels of
protein, fat and amino acids
1 2
3
Diet LPLF
LPHF HPLF
HPHF IMB-HPLF
IMB-HPHF Pooled SEM
Proximate composition
c4 a
d b
d b
Moisture 71.7
69.0 72.4
69.8 72.7
70.1 0.18
b b
c b
b a
Ž .
Crude protein N=6.25 15.6
15.3 16.3
15.4 15.5
14.6 0.14
b d
a c
a cd
Crude fat 10.0
13.3 8.6
12.1 9.0
12.6 0.25
ab ab
b ab
ab a
Crude ash 2.2
2.1 2.3
2.1 2.2
2.1 0.05
5
Amino acid composition g r100 g protein Arginine
6.51 6.67
6.47 6.70
6.81 6.62
0.094
cd abc
bc d
ab a
Histidine 3.16
3.08 3.15
3.25 3.01
2.94 0.041
ab a
ab ab
b ab
Isoleucine 4.39
4.34 4.39
4.37 4.43
4.39 0.017
ab a
ab b
ab ab
Leucine 7.83
7.77 7.84
8.08 8.01
7.91 0.078
Lysine 8.65
8.58 8.66
8.91 8.81
8.58 0.123
Methionine 3.23
3.23 3.26
3.32 3.27
3.27 0.041
ab ab
a ab
b ab
Phenylalanine 4.48
4.45 4.39
4.45 4.52
4.45 0.031
a a
a b
a a
Tyrosine 3.39
3.33 3.33
3.45 3.34
3.35 0.021
Threonine 5.23
4.84 5.16
4.71 4.39
4.66 0.242
Valine 5.00
4.87 5.02
4.90 4.85
4.97 0.070
Alanine 6.70
7.09 6.56
6.98 7.15
6.94 0.219
Aspartic acid 9.70
9.63 9.95
9.37 9.29
9.71 0.366
Glutamic acid 13.76
13.51 13.95
13.50 13.73
13.62 0.144
a c
a a
ab bc
Glycine 7.39
8.01 7.50
7.40 7.63
7.88 0.102
Proline 4.71
4.43 4.50
4.42 4.57
4.48 0.176
Hydroxyproline 1.26
1.48 1.29
1.10 1.26
1.53 0.218
Serine 4.15
4.37 4.12
4.40 4.63
4.45 0.190
bc abc
c abc
ab a
Taurine 0.50
0.39 0.52
0.38 0.35
0.31 0.046
1
Ž .
Average value of two pooled samples four fishrsample from duplicate groups.
2
LP; low protein with balanced amino acid diet, HP; high protein with balanced amino acid diet, IMB-HP; high protein with imbalanced amino acid diet, LF; low fat diet, HF; high fat diet.
3
Standard error of the means.
4
Ž .
Values in the same row with the same superscript are not different P 0.05 .
5
Tryptophan and cystine contents were not determined.
Ž .
Dietary fat levels LPLF vs. LPHF, HPLF vs. HPHF, IMB-HPLF vs. IMB-HPHF Ž
. did not markedly affect the plasma FAA levels. However, higher levels P - 0.05 of
Ž .
aromatic amino acids phenylalanine and tyrosine were found in the HF diet group than Ž
. the LF diet group. In addition, the taurine level of the HF group was lower P - 0.05
than the LF group. Individual free EAA levels except for arginine, of the IMB diet group were lower
Ž .
P - 0.05 than those of the HP group, and were generally lower than the levels of the Ž
. LP group. Taurine level of the IMB diet group was also lower P - 0.05 than the HP
group fed the same fat level diet. The levels of serine, glycine and hydroxyproline of the Ž
. IMB diet group were higher P - 0.05 than the HP diet group, so that the total NEAA
Ž .
level of the IMB group was higher P - 0.05 than the HP group.
Table 5 Ž
. Levels of free amino acids and related compounds nMrml in plasma of rainbow trout fed diets containing
different levels of protein, fat and amino acids
1 2
3
Diet LPLF
LPHF HPLF
HPHF IMB-HPLF
IMB-HPHF Pooled SEM
b4 a
c b
ab a
Taurine 142
61 201
143 87
38 18.7
ab a
b b
a b
Aspartic acid 10
7 12
10 7
11 0.8
a a
b b
a a
Threonine 253
202 419
400 293
252 30.2
a a
a a
b b
Serine 221
264 262
288 440
438 21.6
a a
b b
a a
Asparagine 494
547 772
753 517
559 42.7
ab a
c b
a ab
Glutamic acid 69
62 95
78 57
71 4.8
a ab
b b
ab b
Glutamine 304
346 401
411 342
390 24.2
ab a
ab bc
d cd
Glycine 1199
996 1496
1583 2324
2068 167.3
ab a
ab ab
b ab
Alanine 434
398 473
479 538
461 37.9
b b
b b
a b
Citruline 37
38 42
42 30
40 2.1
b b
c c
a a
Valine 750
682 915
960 467
506 39.6
bc b
b c
b a
Cystine 8
6 6
9 5
2 0.8
b b
b b
a a
Methionine 192
213 214
209 130
148 14.5
5
Cystathionine ND
ND ND
ND ND
ND
b b
c c
a a
Isoleucine 285
249 362
379 156
153 17.1
b b
c c
a a
Leucine 518
468 662
681 300
297 29.1
b d
b c
a b
Tyrosine 110
220 109
148 57
94 11.7
ab de
cd e
a bc
Phenylalanine 137
196 172
199 119
152 8.0
b a
ab a
ab ab
b-Alanine 55
36 44
36 46
47 3.9
g-Aminobutyric acid ND
ND ND
ND ND
ND Tryptophan
16
a
18
a
28
b
31
b
10
a
12
a
2.7 Ethanolamine
ND ND
ND ND
ND ND
a a
a a
a b
Ammonia 225
209 222
220 211
249 7.9
a a
a a
b c
Ornithine 11
9 13
15 25
35 3.3
a a
b b
a a
Lysine 194
190 284
291 210
216 21.4
bc b
d cd
a a
Histidine 186
177 233
211 124
128 10.2
Anserine ND
ND ND
ND ND
ND Carnosine
ND ND
ND ND
ND ND
a a
a a
b b
Arginine 48
54 76
76 122
137 9.9
a a
a a
b b
Hydroxyproline 572
578 763
758 2193
1962 112.4
ab a
b bc
c c
Proline 495
333 576
771 928
1059 95.6
6 b
b c
c a
a
EAAqCqT 2765
2694 3450
3585 1970
2115 145.6
6 a
a b
b c
c
NEAA 3784
3504 4866
5203 7346
7114 328.8
1
Ž .
Average value of 6 fish three fishrgroup from duplicate groups.
2
LP; low protein with balanced amino acid diet, HP; high protein with balanced amino acid diet, IMB-HP; high protein with imbalanced amino acid diet, LF; low fat diet, HF; high fat diet.
3
Standard error of the means.
4
Ž .
Values in the same row with the same superscript are not different P 0.05 .
5
Not detected.
6
EAAqCqT; total amount of 10 essential amino acids, cystine and tyrosine, NEAA; total amount of non-essential amino acids including hydroxyproline.
3.4. LiÕer free amino acids The levels of FAA and related compounds in liver are shown in Table 6.
Ž .
In liver, increment of dietary protein level increased P - 0.05 the levels of several Ž
free EAA such as threonine and branched-chain amino acids isoleucine, leucine, and
Table 6 Ž
. Levels of free amino acids and related compounds nmolrg wet tissue in liver of rainbow trout fed diets
containing different levels of protein, fat and amino acids
1 2
3
Diet LPLF
LPHF HPLF
HPHF IMB-HPLF
IMB-HPHF Pooled SEM
d4 ab
d c
b a
Taurine 18 468
5035 20 488
13 943 7604
2218 1006.4
a a
a a
b c
Aspartic acid 1234
1258 1124
1072 1672
2008 102.9
a a
b b
a a
Threonine 471
327 620
650 425
433 49.0
a a
a a
b b
Serine 641
652 935
950 2500
2753 105.4
bc ab
b a
b c
Asparagine 1370
999 1165
753 1241
1652 131.5
a b
a a
a a
Glutamic acid 7226
9915 6408
7444 6916
7753 607.1
a abc
ab a
c bc
Glutamine 2018
2408 2132
1887 2685
2612 169.3
a a
a a
c b
Glycine 1761
1992 2199
2365 4569
3419 288.5
bc bc
a a
b c
Alanine 5842
5798 3459
3163 5132
6130 285.6
ab a
b b
ab ab
Citruline 304
225 319
322 255
291 27.4
b a
bc c
a a
Valine 735
488 837
885 475
480 37.0
Cystine 53
31 46
49 40
36 6.7
ab b
b b
a a
Methionine 122
127 133
141 92
94 9.9
b a
b b
b b
Cystathionine 113
66 154
138 133
124 13.9
b a
c c
a a
Isoleucine 361
270 431
463 236
222 17.4
b a
c c
a a
Leucine 721
592 863
942 508
491 34.4
abc c
bc c
a ab
Tyrosine 244
343 285
327 172
217 31.9
ab bc
bc c
a a
Phenylalanine 249
282 290
314 203
222 18.9
b-Alanine 441
b
738
c
444
b
408
ab
319
a
467
b
33.8
5
g-Aminobutyric ND ND
ND ND
ND ND
acid
a b
b c
a
Tryptophan 6
28 31
47 ND
10 3.9
c a
c d
ab bc
Ethanolamine 85
59 85
96 65
75 3.6
a a
c c
c b
Ammonia 3256
3253 4148
3998 4308
3598 108.6
a a
a ab
ab b
Ornithine 102
109 116
133 156
181 16.8
ab a
b b
ab ab
Lysine 438
375 513
529 449
447 41.1
b b
b b
a a
Histidine 1135
1132 1097
1149 822
895 37.7
Anserine ND
ND ND
ND ND
ND Carnosine
ND ND
ND ND
ND ND
Arginine 130
125 129
133 104
114 13.8
a a
a a
c b
Hydroxyproline 555 483
661 717
4024 2653
341.0
ab a
abc bc
c d
Proline 1487
1088 1773
2085 2468
3734 250.4
6 bc
ab cd
d a
a
EAAqCqT 4778
4100 5344
5687 3593
3666 233.9
6 bc
c a
ab d
d
NEAA 23 399
24 901 19 988
20 687 31 239
33 213 961.4
1
Ž .
Average value of 6 fish three fishrgroup from duplicate groups.
2
LP; low protein with balanced amino acid diet, HP; high protein with balanced amino acid diet, IMB-HP; high protein with imbalanced amino acid diet, LF; low fat diet, HF; high fat diet.
3
Standard error of the means.
4
Ž .
Values in the same row with the same superscript are not different P 0.05 .
5
Not detected.
6
EAAqCqT; total amount of 10 essential amino acids, cystine and tyrosine, NEAA; total amount of non-essential amino acids including hydroxyproline.
. valine , however, the levels of methionine, aromatic amino acids, histidine, and arginine
Ž .
were not different P 0.05 . Due to the decrease of NEAA such as alanine, the total Ž
. NEAA level of the HP diet group was lower P - 0.05 than the LP group.
Although the levels of certain FAA were affected by dietary fat level, the influence of the treatments was not clear. The levels of aromatic amino acids of the HF group
seemed higher than the LF group, however, the differences were not significant. Taurine Ž
. level of the HF group was markedly lower P - 0.05 than the LF group.
Table 7 Ž
. Levels of free amino acids and related compounds nmolrg wet tissue in dorsal white muscle of rainbow
trout fed diets containing different levels of protein, fat and amino acids
1 2
3
Diet LPLF
LPHF HPLF
HPHF IMB-HPLF
IMB-HPHF Pooled SEM
e4 cd
d c
b a
Taurine 873
682 734
659 524
360 23.2
b b
b c
a a
Aspartic acid 463
595 612
886 145
171 66.3
ab a
c bc
a a
Threonine 1004
757 1573
1275 820
863 118.5
bc c
a ab
bc c
Serine 1363
1710 917
1177 1384
1633 109.8
b c
d d
a a
Asparagine 6752
8866 10 471
10 226 3240
3358 384.6
c bc
c c
a b
Glutamic acid 1163
1106 1239
1236 724
943 57.4
ab a
c bc
a bc
Glutamine 1158
1114 1392
1310 973
1317 60.5
a b
ab c
a a
Glycine 26 331
30 514 28 143
33 268 27 535
27 339 813.1
b b
a a
a a
Alanine 4042
3754 2937
2585 2216
2375 261.2
b b
b ab
a ab
Citruline 240
237 232
197 144
197 24.3
c b
c c
a a
Valine 526
424 572
601 281
307 30.2
a a
b a
a a
Cystine 40
37 128
76 36
28 15.2
a b
a a
a a
Methionine 95
127 89
99 84
87 7.0
ab b
c d
a a
Cystathionine 58
66 112
160 19
18 13.1
b b
c c
a a
Isoleucine 194
157 243
243 80
84 13.5
bc b
c c
a a
Leucine 372
304 443
445 170
170 25.1
b c
b b
a b
Tyrosine 85
188 78
91 33
71 9.3
ab d
bc c
a bc
Phenylalanine 97
151 114
123 87
104 7.0
b-Alanine 392
d
298
c
387
d
392
d
139
a
218
b
21.7
5
g-Aminobutyric ND ND
ND ND
ND ND
acid Tryptophan
ND ND
ND ND
ND ND
Ethanolamine ND
ND ND
ND ND
ND
c c
b b
b a
Ammonia 6159
6154 5029
5071 5173
4861 57.5
d ab
a a
bc c
Ornithine 70
27 18
16 43
48 6.8
bc ab
c c
a a
Lysine 806
621 1146
1030 283
404 111.0
b b
c bc
a a
Histidine 8530
8322 10 092
9152 4835
3599 419.4
c b
a a
b a
Anserine 12 886
10 948 9638
9265 10 859
9051 292.5
b a
a a
b c
Carnosine 258
130 139
119 241
553 32.8
a a
a a
b c
Arginine 18
14 19
11 90
192 9.7
a a
a a
b c
Hydroxyproline 5978 7859
5932 6554
11 338 13 306
616.0
b a
b b
a ab
Proline 3426
2042 3443
3990 1964
2807 414.2
6 bc
b d
c a
a
EAAqCqT 12 212
11 164 14 565
13 181 6950
5952 428.8
6 a
c bc
d a
ab
NEAA 51 618
57 792 55 504
60 973 50 580
52 757 1056.4
1
Ž .
Average value of 6 fish three fishrgroup from duplicate groups.
2
LP; low protein with balanced amino acid diet, HP; high protein with balanced amino acid diet, IMB-HP; high protein with imbalanced amino acid diet, LF; low fat diet, HF; high fat diet.
3
Standard error of the means.
4
Ž .
Values in the same row with the same superscript are not different P 0.05 .
5
Not detected.
6
EAAqCqT; total amount of 10 essential amino acids, cystine and tyrosine, NEAA; total amount of non-essential amino acids including hydroxyproline.
In the IMB diet group, levels of most EAA, except for lysine and arginine, were Ž
. lower P - 0.05 than those of the HP group. On the other hand, levels of most NEAA
of the IMB group were higher than the HP group. Thus, compared with the HP group, Ž
. total EAA level of the IMB group was lower
P - 0.05 and total NEAA level was Ž
. higher P - 0.05 .
3.5. White muscle free amino acids The levels of FAA and related compounds in dorsal white muscle are shown in Table
7. In white muscle, although the levels of methionine and aromatic amino acids of the Ž
. HPHF group were lower P - 0.05 than those of the LPHF group, total EAA level of
Ž .
the HP group was higher P - 0.05 than that of the LP group fed the same fat level diet, due to the increase of the other EAA levels. Likewise, the total NEAA level of the
Ž .
HP group was higher P - 0.05 than the LP group. As the individual EAA levels of the HF group tended to be lower than the LF group,
Ž .
the total EAA level of the HPHF group was lower P - 0.05 than the HPLF group. Ž
. Increasing the dietary fat level increased P - 0.05 the levels of aromatic amino acids
Ž .
among the LP groups, however, the effect was insignificant P 0.05 among the HP Ž
. groups. The total NEAA level of the HF group was higher P - 0.05 than the LF group
due mainly to the increase of glycine level. However, this glycine increase was not observed among the IMB diet groups. The taurine level of the HF group was lower
Ž .
P - 0.05 than the LF group. Most of the EAA levels of the IMB diet group were markedly lower than the HP
group, and the total EAA level was nearly half the level of the LP group. Compared with the HP group, the levels of individual NEAA except for serine and hydroxyproline
of the IMB diet group also tended to decrease, so that the total NEAA level was lower Ž
. P - 0.05 than the HP group fed the same fat level diet.
3.6. Brain free amino acids The levels of FAA and related compounds in brain are shown in Table 8.
As the increment of dietary protein level tended to increase individual FAA levels among the HF groups, the total EAA and the NEAA levels of the HPHF group were
Ž .
higher P - 0.05 than the LPHF group. However, such an influence of dietary protein Ž
. level was not different P 0.05 among the LF diet groups.
Ž .
The aromatic amino acid levels of the HF group were higher P - 0.05 than the LF group. The taurine level of the HF group seemed slightly lower than the LF group,
Ž .
however, the influence was significant P - 0.05 only among the IMB diet groups. Although the levels of certain EAA such as branched-chain amino acids and lysine of
Ž .
the IMB diet group were lower P - 0.05 compared to the HP group, the levels of
threonine, phenylalanine, histidine, and arginine were not lower. Accordingly, the total EAA levels in the HP and the IMB groups fed the same fat level diet were not different
Ž .
Ž .
P 0.05 . The total NEAA level of the IMB group was higher P - 0.05 than the HP group, due mainly to the increase of serine and hydroxyproline levels.
Table 8 Ž
. Levels of free amino acids and related compounds nmolrg wet tissue in brain of rainbow trout fed diets
containing different levels of protein, fat and amino acids
1 2
3
Diet LPLF
LPHF HPLF
HPHF IMB-HPLF
IMB-HPHF Pooled SEM
b4 b
c c
b a
Taurine 14 498
13 805 16 359
15 977 14 248
12 967 274.9
b b
b b
a a
Aspartic acid 572
572 586
607 500
480 19.5
ab a
c c
c bc
Threonine 589
360 564
567 624
547 30.7
a a
a a
b b
Serine 564
522 494
572 935
1061 45.0
bc c
ab b
a b
Asparagine 184
209 144
162 114
160 13.0
a a
b b
ab a
Glutamic acid 5864
5828 6285
6255 6117
5844 111.6
a a
b b
b c
Glutamine 3323
3232 4012
4247 4232
4853 111.7
bc a
ab bc
bc c
Glycine 1242
964 1148
1263 1311
1415 73.1
bc a
abc c
ab bc
Alanine 370
295 341
385 324
353 16.1
a a
a b
a a
Citruline 72
68 64
108 69
75 9.6
d bc
b cd
a a
Valine 203
168 152
186 99
122 9.3
Cystine 23
31 23
35 15
18 8.5
a ab
a b
a a
Methionine 37
47 31
59 26
31 6.8
a a
ab ab
b ab
Cystathionine 22
19 25
25 29
24 2.3
c ab
bc c
a ab
Isoleucine 75
57 62
77 44
46 5.3
c b
bc c
a a
Leucine 173
140 149
171 88
108 8.4
bc e
ab d
a cd
Tyrosine 67
133 54
87 46
78 5.0
a bc
a bc
ab c
Phenylalanine 91
120 87
118 103
122 5.5
b-Alanine 68
c
64
bc
41
ab
52
ab
36
a
53
ab
7.6
a a
b b
b b
g-Aminobutyric 2511 2573
2953 2804
2948 3005
70.7 acid
5
Tryptophan ND
ND ND
ND ND
ND
c ab
a a
b c
Ethanolamine 587
436 365
399 496
588 28.3
ab a
ab b
a b
Ammonia 1921
1762 2126
2305 1695
2322 140.8
abc a
ab bc
ab c
Ornithine 30
24 27
38 28
40 3.6
bc ab
c d
a a
Lysine 291
249 304
360 216
216 14.5
ab a
ab ab
a b
Histidine 822
701 1009
1010 707
1110 109.2
Anserine ND
ND ND
ND ND
ND
a a
ab ab
c b
Carnosine 2186
2156 2292
2326 2837
2427 71.7
a a
a b
b c
Arginine 87
84 93
110 123
141 5.1
a a
a a
b b
Hydroxyproline 381 447
403 425
1316 1401
42.2
ab a
ab bc
cd d
Proline 218
164 225
256 332
382 26.5
6 abc
a abc
c ab
bc
EAAqCqT 2341
2048 2518
2741 2077
2567 152.7
6 ab
a b
b c
c
NEAA 12 973
12 141 13 728
14 172 15 333
15 762 388.8
1
Ž .
Average value of 6 fish three fishrgroup from duplicate groups.
2
LP; low protein with balanced amino acid diet, HP; high protein with balanced amino acid diet, IMB-HP; high protein with imbalanced amino acid diet, LF; low fat diet, HF; high fat diet.
3
Standard error of the means.
4
Ž .
Values in the same row with the same superscript are not different P 0.05 .
5
Not detected.
6
EAAqCqT; total amount of 10 essential amino acids, cystine and tyrosine, NEAA; total amount of non-essential amino acids including hydroxyproline.
3.7. Relationship in amino acid leÕels between diet and tissue The relationships between dietary amino acid patterns and tissue FAA patterns are
Ž .
given in Table 9. High correlations P - 0.01 were found between dietary and plasma
Table 9 Correlations between the dietary amino acid patterns and tissue free amino acid patterns of rainbow trout fed
diets containing different levels of protein, fat and amino acids
a
Diet LPLF
LPHF HPLF
HPHF IMB-HPLF
IMB-HPHF Plasma
UU UU
UU UU
UU UU
bc
EAAqCqT 0.7609
0.7663 0.7856
0.7929 0.7526
0.7548
UU UU
bd
NEAA 0.1374
0.0861 0.1245
0.1613 0.9323
0.9229 LiÕer
U U
EAAqCqT 0.4986
0.3609 0.5992
0.6074 0.4469
0.3953 NEAA
0.5508 0.6642
0.7420 0.8059
0.2303 y0.0071
Muscle EAAqCqT
y0.2000 y0.2176
y0.1993 y0.1922
y0.2470 y0.2118
U U
NEAA 0.0084
y0.0357 y0.0116
0.0112 0.8912
0.9013 Brain
EAAqCqT 0.0216
y0.0179 y0.0598
y0.0378 y0.0690
y0.1491
U U
U
NEAA 0.8132
0.8051 0.8151
0.8156 0.0894
0.0910
a
LP; low protein with balanced amino acid diet, HP; high protein with balanced amino acid diet, IMB-HP; high protein with imbalanced amino acid diet, LF; low fat diet, HF; high fat diet.
b
EAAqCqT; 10 essential amino acids, cystine and tyrosine, NEAA; non-essential amino acids excluding hydroxyproline.
c
Tryptophan is excluded from calculation when free tryptophan is not detected in the tissue.
d
In calculation, free asparagine and glutamine levels are included in free aspartic acid and glutamic acid levels, respectively.
U
P - 0.05,
UU
P - 0.01.
Ž .
EAA patterns. In liver, the correlations were significant P - 0.05 only in the EAA patterns of the HP groups. In muscle and brain, the correlations in EAA patterns were
very low. High correlations between dietary and tissue NEAA patterns were observed in plasma and muscle of the IMB groups, and in brain of the balanced amino acid diet
groups.
The correlations between the levels of certain amino acids in the diets and tissue through the treatments are given in Table 10. In plasma and liver, high correlations were
found for several EAA such as isoleucine, lysine and threonine. In plasma, the dietary Ž
. arginine levels showed a strong positive correlation
P - 0.001 to the tissue free Ž
. arginine levels, however, the correlation was negative P - 0.05 in liver. In muscle and
brain, the correlations between dietary and tissue amino acid levels were significant for only one or two amino acids. Among NEAA, relatively high correlations were found for
glycine in plasma and liver, and proline in plasma and brain.
When the tissue levels of certain EAA in all the treatments were compared with the Ž
. dietary ArE ratios of the amino acid, high correlations P - 0.01 were also observed
for histidine and methionine in plasma and liver. Likewise, high correlations between tissue FAA levels and the dietary ArE ratios were found for several EAA of muscle and
liver.
T. Yamamoto
et al.
r Aquaculture
182 2000
353 –
372 366
Table 10 Correlations between levels of certain amino acids in the diets and tissues for all dietary treatments
Amino acid Plasma
Liver Muscle
Brain
a b
Diet ArE ratio
Diet ArE ratio
Diet ArE ratio
Diet ArE ratio
UUU UU
UU U
U U
Arginine 0.9802
0.9400 y0.8065
y0.9402 0.7997
0.8942 0.9435
0.8850
U UU
UU
Histidine 0.6903
0.8947 0.3051
0.9793 0.5176
0.9594 0.5795
y0.0667
U U
U U
U
Isoleucine 0.8331
0.8709 0.8667
0.7636 0.7901
0.8964 0.5004
0.8191
U U
U U
Leucine 0.7924
0.8736 0.8509
0.7692 0.7180
0.9098 0.4203
0.9095
UUU UU
U
Lysine 0.9911
0.3006 0.9265
0.1392 0.6388
0.8416 0.6310
0.7797
UU UU
Methionine 0.5049
0.9628 0.6253
0.9487 y0.1773
0.5904 0.3806
0.6034
U
Cystine 0.6662
0.7881 0.4736
0.4397 0.8890
0.5096 0.6323
0.7385
U
Phenylalanine 0.4445
0.6464 0.6161
0.8570 0.0558
0.6025 y0.1592
y0.2757
U
Tyrosine 0.1858
0.6586 0.5916
0.8261 0.0104
0.5803 y0.1002
0.3883
UU U
U
Threonine 0.9683
0.2730 0.9140
0.3730 0.8684
0.5087 0.6028
y0.5432 Tryptophan
0.9857
UUU
0.7309 0.8655
U
0.6610 NC
c
NC NC
NC
U U
U
Valine 0.7370
0.8628 0.7744
0.6994 0.6318
0.8971 0.0977
0.8777
U
Alanine 0.7358
0.1400 y0.8841
y0.0162 y0.1571
UU
Aspartic acid 0.6472
0.0826 y0.0259
y0.4777 0.9629
U
Glutamic acid 0.8964
y0.6202 0.5688
0.6765 y0.5564
UU UU
Glycine 0.9397
0.9359 y0.3701
0.7286 0.6952
U U
U
Proline 0.8925
0.8013 0.0140
0.8145 0.8748
UUU
Serine 0.1714
0.1597 y0.7400
0.0020 y0.9795
a
Based on percentage amino acid content in the diets.
b
Based on ArE ratio of the diets.
c
Not calculated because free tryptophan was not detected in the tissues.
U
P - 0.05,
UU
P - 0.01,
UUU
P - 0.001.
4. Discussion
