rate of 0.6 mlrmin at 308C and detected at 345 nm. Retinol was separated using a Ž
. mixture of B and C 15:85, by vol. at a flow rate of 0.4 mlrmin at 308C and detected at
Ž 325 nm. A vitamin-A–alcohol solution purity 98, Fluka Chemie, Buchs, Switzer-
. Ž
land and all-trans-retinoic acid
purity 95, Biomol Research Lab., Plymouth .
Meeting, PA, USA were used as the authentic standards for plasma retinoid determina- tion.
Data were statistically compared between the control and the fish fed retinoids using Ž
. Student’s t-test P - 0.05 , without any transformations of percentage data prior to the
analysis.
3. Results
Mortality during the feeding trial was low and limited to one fish in one tank in both Ž
. the retinoic acid groups Table 1 . The final body weight of the 100 mgrkg retinoic acid
Ž .
Ž group 42.9 g, P - 0.05 compared to control was slightly lower than weights 45.3–45.5
. Ž
. g of the other groups, but the weight gain 400 was not significantly different from
Ž .
Ž .
that of the control fish 419 . Feed efficiency 1.09–1.12 and daily feed intake Ž
. 3.03–3.17 of wet biomassrday were not affected by the treatments. No signs of
hypervitaminosis A were observed in the test fish. The dietary treatments did not affect the whole body crude protein and fat contents.
Ž .
Hepatosomatic index of the fish fed the 100 mgrkg retinyl acetate diet 1.50 tended to Ž
. Ž .
be higher but not significantly different from that of the control fish 1.35 Table 2 .
Visceral adiposomatic index was highest in the fish fed the 100 mgrkg retinoic acid diet
Table 1 Ž
. The effects of dietary retinoids on growth performance of juvenile red sea bream mean valuese
Diet Control
Retinyl acetate Retinoic acid
Retinoic acid Ž
. Ž
. Ž
. 100 mgrkg diet
10 mgrkg diet 100 mgrkg diet
Ž . Initial body weight g
8.720.02 8.570.15
8.610.24 8.580.02
Ž . Final body weight g
45.280.47 45.310.80
45.490.52 42.890.17
weight gain 4195
4290 4299
4003
a
Feed efficiency 1.120.01
1.090.01 1.100.00
1.120.01
b
Daily feed intake 3.070.03
3.170.03 3.140.09
3.030.02 Ž .
Mortality 0.00.0
0.00.0 2.52.5
2.52.5
c
Whole body composition Moisture
65.81.4 65.50.8
65.90.1 66.00.6
Crude protein 17.80.1
17.80.2 18.00.2
17.80.3 Crude fat
11.00.8 11.20.6
11.50.6 10.10.8
Data were statistically different when compared between the control and retinoid diets using Student’s Ž
. t-test P - 0.05 .
a
Weight gainrfeed intake.
b
Ž . wŽ
. 4
Ž .x
Feed intake g =100r initial weightqfinal weight r2 =rearing period days .
c
Moisture, crude protein and crude fat contents of the initial fish were 73.4, 16.5 and 3.4, respectively.
Table 2 The effects of dietary retinoids on organ index, body lipid contents, and blood parameters of red sea bream
Ž .
mean valuese Diet
Control Retinyl acetate
Retinoic acid Retinoic acid
Ž .
Ž .
Ž .
100 mgrkg diet 10 mgrkg diet
100 mgrkg diet
a
Adiposomatic index 2.900.15
3.460.15 3.280.11
4.190.19
b
Hepatosomatic index 1.350.08
1.500.12 1.270.08
1.280.07
c
Lipid contents Visceral adipose tissue
76.50.6 79.31.2
79.31.2 83.41.7
Liver 24.02.6
28.01.3 24.01.8
24.60.9 Dorsal white muscle
1.770.03 1.760.09
1.600.09 1.550.04
Blood plasma
d
Ž .
NEFA mEqrl 14815
12316 11320
6112 Ž
. Triacylglycerol mgrl
3130193 1845119
2944202 3061152
e
Ž .
Retinol ngrml 7143
8093 64620
60146
e
Ž .
Retinoic acid ngrml 40
60 200
22334 Data were statistically different when compared between the control and retinoid diets using Student’s
Ž .
t-test P - 0.05 .
a
Ž .
Visceral adipose tissue weightrbody weight =100.
b
Ž .
Liver weightrbody weight =100.
c
Ž .
Chloroform–methanol 2:1, by vol. extracts.
d
Non-esterified fatty acids.
e
Ž .
Plasma retinoid levels at 6-h post-feeding. Initial levels 48 h-starvation of plasma retinol and retinoic acid levels were 76210 and 50 ngrml, respectively.
Ž .
Ž 4.19, P - 0.05 for control , and the index of the fish fed the retinyl acetate diet 3.46,
. Ž
. P - 0.05 for control was significantly higher than that of the control fish 2.90 . Liver
Ž .
lipid contents were not related to the dietary treatments 24.0–28.0 . However, in the Ž
fish fed the 100 mgrkg retinoic acid diet, lipid in the visceral adipose tissue 83.4, .
Ž P - 0.05 for control was highest and that of the dorsal white muscle 1.55, P - 0.05
. Ž
for control was lowest. Plasma NEFA level of the 100 mgrkg retinoic acid group 61 .
Ž mEqrl, P - 0.05 for control was lower than those of the other groups 113–148
. Ž
mEqrl . Plasma triacylglycerol level of the 100 mgrkg retinyl acetate group 1845 .
Ž mgrl, P - 0.05 for control was lower than those of the other groups 2944–3130
. mgrl . Plasma retinoic acid levels at 6-h post-feeding of the fish fed the 10 and 100
Ž .
mgrkg retinoic acid diets 20 and 223 ngrml, respectively, P - 0.05 for control were Ž
. Ž
. higher than those of the control 4 ngrml and retinyl acetate group 6 ngrml . The
Ž plasma retinol level at 6-h post-feeding of the retinyl acetate group
809 ngrml, .
Ž .
P - 0.05 for control was higher than those of the other groups 601–714 ngrml .
4. Discussion
