Results Directory UMM :Data Elmu:jurnal:A:Aquaculture:Vol194.Issue1-2.2001:

3. Results

3.1. Lipase actiÕity Retention of enzymatic activity in feed oils was examined 240 min post-addition of lipase. At time 0, percent FFA presence in the oil was 5.32 0.74. Similar values Ž . 5.26 1.52; P 0.05 were recorded for control samples 240 min later, but high lipase Ž . supplementation increased percent FFA presence significantly P - 0.05; 6.90 1.49 . Following a reaction period of 1440 min, lipase addition resulted in a 29 increase in Ž . Ž FFA P - 0.05 when compared to control oil 5.97 1.46 vs. 4.64 0.64, respec- . Ž . tively . Differences P - 0.05 in FFA presence were also discernible between the high Ž . Ž . lipase supplemented 6.63 0.47 and control 6.05 0.46 and lipase inactivated Ž . 6.07 0.46 feeds 60 min post-enzyme addition. Each feed type returned identical FFA profiles. 3.2. Growth and fillet composition No differences were perceptible in the performance of the different groups with respect to specific growth rates or increments in length and weight throughout the trial Ž . Ž . Table 2 . Condition factor, however, was lower P - 0.05 in fish fed the control diet. Table 2 Ž . Summary of performance characteristics of rainbow trout following 202 days feeding with control C, D and Ž . lipase supplemented A, B diets Diet A B C D Growth Ž . Length cm 26.54.19 26.83.88 26.83.96 27.13.87 Ž . Final wt. g 266.213.96 277.213.41 273.913.38 277.213.60 y1 Ž . SGR day 0.380.02 0.390.02 0.380.02 0.390.02 L y1 Ž . SGR day 1.200.05 1.210.06 1.210.05 1.210.05 W FCR 0.850.44 0.800.07 0.850.24 0.820.34 a a a b Condition factor 1.410.02 1.420.03 1.400.02 1.370.03 Mass Ž . Fillet yield 53.371.75 53.151.03 52.721.47 53.851.45 Ž . Carcass 40.801.99 41.191.03 41.171.47 40.621.45 Cardiac index 0.150.007 0.150.009 0.160.008 0.150.007 1 a a b a HSI 1.310.04 1.280.05 1.450.06 1.290.05 a,b b a a,b Gut index 9.340.20 8.940.27 9.440.32 9.130.26 Fillet composition Moisture 72.950.77 73.050.93 72.770.90 73.370.67 Lipid 7.680.84 7.280.82 7.310.47 7.680.57 Protein 18.330.16 18.400.16 18.480.19 18.350.27 Ash 1.330.04 1.360.05 1.340.05 1.340.04 Ž . Compositional analyses were performed on fillets ns8 per treatment . All other data sets represent means of Ž . 35 animals per treatment 95 confidence limits Walpole and Myers, 1993 . Different superscripts indicate Ž . significant differences row-wise P - 0.05 . 1 Hepatosomatic index. Identical yields were obtained for fillet percentage and carcass. Differences were seen for hepatosomatic index with fish given the inactivated lipase diets returning relatively Ž . larger livers P - 0.05 than all other groups. The same fish also contrasted with respect Ž . to their gut index, which was higher P - 0.05 when compared against trout fed low Ž . lipase diets Table 2 . No differences were recorded in FCRs between groups throughout Ž . the trial P 0.05; Table 2 Table 3 Ž . Free fatty acid profiles of fillets of rainbow trout prior to experimental start day 0 and following 202 days feeding with control and lipase supplemented diets FFA Initial profile Final profile A B C D Area Area Area Area Area a a,b a,b b b 10:0 0.030.01 0.050.00 0.060.00 0.060.00 0.060.00 a b b a b 12:0 0.070.02 0.040.00 0.040.00 0.050.00 0.040.00 a b b d b 14:0 3.880.08 5.000.06 5.020.07 5.110.09 4.910.05 a b b b a,b 16:0 15.720.21 16.340.21 16.630.22 16.610.24 16.280.17 a b b b b 16:1 ny7 6.510.32 5.300.10 5.380.08 5.360.12 5.370.11 a b b b a,b 18:0 2.560.09 2.200.06 2.200.06 2.250.08 2.280.07 a a a a a 18:1 ny9 15.210.48 15.170.28 15.450.18 15.290.22 15.400.28 a a a a a 18:1 ny7 2.440.07 2.450.02 2.480.02 2.440.02 2.440.02 a a,b a,b a,b b 18:2 ny6 3.370.11 3.250.05 3.270.05 3.200.05 3.170.03 a b b b b 18:3 ny3 1.100.04 1.410.02 1.410.03 1.390.02 1.390.02 a b b b a,b 18:4 ny3 1.670.06 1.770.03 1.740.03 1.780.03 1.740.04 a b b b b 20:1 ny9 4.590.19 5.940.19 5.810.06 5.940.23 5.660.05 a b b b b 20:1 ny7 0.330.03 0.240.00 0.240.00 0.240.00 0.240.01 a b b b b 20:2 ny6 0.330.02 0.400.01 0.400.01 0.380.01 0.400.01 a b b b b 20:3 ny6 0.300.09 0.160.00 0.160.01 0.160.01 0.150.01 a b b b b 20:4 ny6 0.450.01 0.390.00 0.390.01 0.390.00 0.400.01 a b b b b 20:3 ny3 0.150.03 0.200.01 0.190.01 0.190.01 0.190.01 a b b b b 20:4 ny3 1.240.10 1.310.05 1.360.06 1.310.07 1.350.03 a b b b b 20:5 ny3 5.840.21 4.830.10 4.770.08 4.770.08 4.940.10 a b b b b 22:1n11q13 5.810.25 7.870.18 7.720.14 7.730.20 7.670.12 a a,b a,b b a,b 22:1 ny9 0.560.03 0.500.02 0.510.02 0.490.01 0.510.02 a a,b a,b a,b b 22:1 ny7 0.190.06 0.120.01 0.110.01 0.110.01 0.100.00 a b,c b,c b a,c 22:5 ny3 1.550.07 1.230.04 1.200.04 1.170.03 1.280.03 a b b b b 24:1 0.200.05 0.030.00 0.030.00 0.030.00 0.040.02 a b,c c c b,c 22:6 ny3 17.590.86 15.480.46 15.100.31 15.220.23 15.660.24 a b b b b Saturated 22.270.25 23.630.27 23.940.30 24.070.33 23.570.16 a b b b a Mono-unsaturated 35.850.87 37.620.50 37.730.21 37.620.29 37.430.32 a b b b b PUFA 33.590.88 30.430.57 29.990.47 29.960.34 30.670.35 a b b b b PrS ratio 1.510.05 1.290.04 1.250.03 1.250.03 1.300.02 a b b b b my3 29.140.90 26.230.54 25.770.43 25.820.30 26.550.33 a a,b a,b b b my6 4.450.15 4.200.06 4.220.06 4.130.06 4.120.03 a a,b b a,b a my3r my6 6.550.33 6.250.12 6.110.09 6.250.08 6.450.07 Ž . Different superscripts indicate significant differences row-wise P - 0.05 . Data are presented as 95 Ž . confidence limits Walpole and Myers, 1993 . Proximate analysis revealed similar values across treatments for all parameters Ž . Ž . examined P 0.05; Table 2 . Significant P - 0.05 differences in fillet FFA profiles Ž . were apparent between trial start and termination Table 3 . The overall trend in the total amount of saturated and monounsaturated fatty acids present in the fillets were towards increased levels, irrespective of diet fed. In contrast, the trend for fillet polyunsaturated Ž . Ž . fatty acids PUFA was towards significant P - 0.05 declines, with a concomitant Ž . Ž . decline P - 0.05 in the PUFA to saturated fatty acid ratio Table 3 .

4. Discussion