Chapter 4 Results
4.1 Growth performance of P. monodon
The result of this study demonstrated that the maximum percent specific growth rate was found in tank S5F2 (1.144±1.19) and the minimum was found to be -0.364±0.53 in tank S10F3 (Table 4.1). In this experiment we found a significant effect of feeds and salinities on the %SGR in S10F1, S10F2, S10F3 and S10F4 compared to other treatment groups (P<0.05). The result of this study did not reveal a significant different in the DWG among the treatments. However, the higher DWG was found in S5F4 (0.750±0.01) and it was lower in S15F3 (0.000±0.10). Similarly, no significant differences was observed in DGR as well as in %RGR values. The maximum DGR and RGR was found in S15F2, 10.760±0.08 and 378.143±26.03 respectively. However, it was minimum in S10F1, -0.253±0.53 and -4.553±20.68 respectively. In addition, initial and final body weight of shrimp was found S10F1, 1.829±0.22 and 2.295±0.56 respectively and was minimum in S20F3, 1.023±.08 and in S5F2, 1.211±0.11. There is no significance differences in initial and final body weight. In case of weight gain, it was higher in S10F3, 4.842±.04 and minimum in S15F3, -0.014±2.72 (Table 3.1).
4.2 Effect of feeds and salinities on combined dependent variables
Different multivariate test statistics (e.g. Pillai’s Trace, Wilks’ Lambda, Hotelling’s Trace and Roy’s Largest Root) showed statistical significance of different effects of the independent variable salinity on the combined dependent variable, F(15, 77.697) = 1.808, p = 0.048; Wilks’ Λ = 0.438. The most commonly recommended multivariate statistic to use is Wilks’ Lambda has been used for interpretation of the results. There was no statistically significant effect was observed in the interaction effect between treatment and salinity on the combined dependent variables, F(45, 128.354) = 0.946, p = .573; Wilks’ Λ = .278. Similarly, four feed treatments did not show any significant differences on the combined dependent variables, F(15, 77.697) = 1.071, p = 0.397 ; Wilks’ Λ =0.595 (Table 3.2).
Table 4.1 Growth parameters (W0, Wt, WG, %SGR, DWG, DGR, %RGR) (mean ± standard error) of P. monodon treated with four different experimental diets and at different salinities. Different superscript letters (effect of feed) and estarics (effect of salinities) indicate significant difference among the treatments (Two-way multivariate analysis of variance, P<0.05).
| Treatment | W0 | Wt | WG | %SGR | DWG | DGR | %RGR |
|---|---|---|---|---|---|---|---|
| S5F1 | 1.279±.03 | 1.782±.36 | 1.656±.95a* | .652±.39a* | .037±.02a* | 3.681±2.11a* | 126.941±70.46a* |
| S5F2 | 1.223±.14 | 1.211±.11 | -.114±.82a* | 1.144±1.19a* | 0.075±.08a* | 7.507±8.15a* | 188.389±194.20a* |
| S5F3 | 1.199±.07 | 1.564±.10 | 3.499±.32a* | 0.802±.28a* | 0.079±.03a* | 7.919±3.45a* | 294.576±136.95a* |
| S5F4 | 1.121±.20 | 1.425±.20 | 2.907±.63a* | 0.803±.31a* | 0.750±.01a* | 7.500±3.37a* | 250.706±87.19a* |
| S10F1 | 1.829±.22 | 2.295±.56 | 3.378±3.67a* | -.011±.05a** | 0.003±.03a* | -0.253±.53a* | -4.553±20.68a* |
| S10F2 | 1.402±.05 | 1.496±.21 | 0.544±1.22a* | 0.104±.23a** | 0.012±.02a* | 1.208±2.70a* | 32.111±85.83a* |
| S10F3 | 1.293±.09 | 1.813±.09 | 4.842±.04a* | -.364±.53a** | .004±.06a* | .437±2.17a* | 11.668±72.83a* |
| S10F4 | 1.566±.22 | 1.940±.20 | 3.254±.93a* | .839±.49a** | 0.098±.01a* | 9.810±6.30a* | 306.101±169.03a* |
| S15F1 | 1.242±.04 | 1.798±.18 | 3.563±1.56a* | 0.588±.05a* | 0.078±0.0a* | 7.775±.71a* | 291.503±20.03a* |
| S15F2 | 1.341±.41 | 1.215±.28 | 0.197±0.98a* | 0.757±.06a* | 0.108±0.0a* | 10.760±.08a* | 378.143±26.03a* |
| S15F3 | 1.493±.17 | 1.574±.16 | -.014±2.72a* | 0.062±.51a* | 0.000±0.10a* | -.031±6.04a* | 36.287±167.92a* |
| S15F4 | 1.411±.11 | 1.828±.43 | 3.81±3.19a* | 0.574±.32a* | 0.067±.00a* | 6.673±4.02a* | 294.078±180.06a* |
| S20F1 | 1.233±.19 | 1.826±.52 | 3.375±1.52a* | 0.574±0.18a* | 0.065±.04a* | 6.459±1.39a* | 293.159±104.77a* |
| S20F2 | 1.371±.17 | 2.170±72 | 4.415±2.84a* | 0.502±0.18a* | 0.072±.02a* | 7.230±2.06a* | 223.903±75.89a* |
| S20F3 | 1.023±.08 | 1.353±.22 | 3.003±1.81a* | 0.480±0.39a* | 0.085±.07a* | 8.474±7.08a* | 256.075±199.77a* |
| S20F4 | 1.204±10 | 1.306±.07 | 1.417±1.33a* | 0.189±.31a* | 0.032±.03a* | 3.171±2.96a* | 137.960±113.45a* |
Note that, W0= Initial weight, Wt= Final weight ,WG= Weight gain, %SGR= Percentage specific growth rate, DWG= Daily weight gain, DGR= Daily growth rate, %RGR= Percentage relative growth rate. S5= Salinity 5 ppt, S10= Salinity 10 ppt, S15= Salinity 15 ppt, S20=Salinity 20ppt. *F1= Feed 1, F2= Feed 2, F3= Feed 3, F4= Feed 4.
| Effect | Value | F | Hypothesis df | Error df | Sig. | |
|---|---|---|---|---|---|---|
| Intercept | Pillai’s Trace | .594 | 14.653b | 3.000 | 30.000 | .000 |
| Wilks’ Lambda | .406 | 14.653b | 3.000 | 30.000 | .000 | |
| Hotelling’s Trace | 1.465 | 14.653b | 3.000 | 30.000 | .000 | |
| Roy’s Largest Root | 1.465 | 14.653b | 3.000 | 30.000 | .000 | |
| Treatment | Pillai’s Trace | .200 | .763 | 9.000 | 96.000 | .651 |
| Wilks’ Lambda | .812 | .727 | 9.000 | 73.163 | .683 | |
| Hotelling’s Trace | .217 | .692 | 9.000 | 86.000 | .715 | |
| Roy’s Largest Root | .107 | 1.144c | 3.000 | 32.000 | .346 | |
| Salinity | Pillai’s Trace | .499 | 2.126 | 9.000 | 96.000 | .034 |
| Wilks’ Lambda | .563 | 2.165 | 9.000 | 73.163 | .034 | |
| Hotelling’s Trace | .668 | 2.129 | 9.000 | 86.000 | .035 | |
| Roy’s Largest Root | .419 | 4.465c | 3.000 | 32.000 | .010 | |
| Treatment * Salinity | Pillai’s Trace | .553 | .804 | 27.000 | 96.000 | .737 |
| Wilks’ Lambda | .533 | .786 | 27.000 | 88.258 | .757 | |
| Hotelling’s Trace | .724 | .769 | 27.000 | 86.000 | .778 | |
| Roy’s Largest Root | .440 | 1.566c | 9.000 | 32.000 | .168 |
4.3 Effect of feeds and salinities on individual dependent variables
Tests of between-subjects effects of multivariate analysis of variance showed that there was no significant difference in the interaction effect between treatment and salinity on Wt, F(9,.286) =.871, p = .560; Type III Sum of Squares = 2.575; WG, F(9, 8.945) = 0.888, p = 0.546; Type III Sum of Squares = 80.504; SGR, F(9, 0.295) = 0.523, p = 0.847; Type III Sum of Squares = 2.654; on DWG, F(9, 0.04) = 0.888, p = 0.546; Type III Sum of Squares = 0.040; on DGR, F(9, 44.172) = 0.888, p = 0.546; Type III Sum of Squares = 397.549 and for RGR, F(9, 46382.390) = 1.019, p = .446; Type III Sum of Squares = 417441.510 (Table 4.3).
Different feeds had no significant effect on the growth Penaeus monodon (e.g.Wt, DW, SGR, DWG, DGR, RGR) with the F and P values; for Wt, F(3,.390) =1.186, p = .330; Type III Sum of Squares = 1.169; WG, F(3, 8.049) = 0.799, p = 0.503; Type III Sum of Squares = 24.147; SGR, F(3, .369) = .655, p = .586; Type III Sum of Squares = 1.108; for DWG, F(3, 0.002) = .475, p = .702; Type III Sum of Squares = 0.007; for DGR, F(3, 23.639) = .475, p = .702; Type III Sum of Squares = 70.916 and for RGR, F(3, 20912.412) = .459, p = .713; Type III Sum of Squares = 62737 (Table 4.3).
Similarly, salinities also did not have significant effect on the growth of Penaeus monodon (e.g. Wt, DW, SGR, DWG, DGR, RGR) with the F and P values; for Wt, F(3,.326) =.992, p = .409; Type III Sum of Squares = .977; WG, F(3, 4.787) = 0.475, p = 0.702; Type III Sum of Squares = 14.361 for SGR, F(3, 1.014) = 1.799, p = .167; Type III Sum of Squares = 3.043; for DWG, F(3, 0.004) = .799, p = .503; Type III Sum of Squares = 0.012 ; for DGR, F(3, 39.748) = .799, p = .503Type III Sum of Squares = 119.243 and for RGR, F(3, 65256.710) = 1.434 p = .251; Type III Sum of Squares = 195770.129 (Table 4.3).
Table 4.3 Effect of independent variables and its interactions on the individual dependent variables (Two-way multivariate analysis of variance, P<0.05).
| Source | Dependent Variable | Type III Sum of Squares | df | Mean Square | F | Sig. |
|---|---|---|---|---|---|---|
| Corrected Model | SGR | 6.804a | 15 | .454 | .805 | .665 |
| DWG | .059b | 15 | .004 | .788 | .681 | |
| DGR | 587.709c | 15 | 39.181 | .788 | .681 | |
| RGR | 675948.875d | 15 | 45063.258 | .990 | .488 | |
| Intercept | SGR | 11.104 | 1 | 11.104 | 19.699 | .000 |
| DWG | .146 | 1 | .146 | 29.415 | .000 | |
| DGR | 1462.601 | 1 | 1462.601 | 29.415 | .000 | |
| RGR | 1821744.322 | 1 | 1821744.322 | 40.022 | .000 | |
| Treatment | SGR | 1.108 | 3 | .369 | .655 | .586 |
| DWG | .007 | 3 | .002 | .475 | .702 | |
| DGR | 70.916 | 3 | 23.639 | .475 | .702 | |
| RGR | 62737.235 | 3 | 20912.412 | .459 | .713 | |
| Salinity | SGR | 3.043 | 3 | 1.014 | 1.799 | .167 |
| DWG | .012 | 3 | .004 | .799 | .503 | |
| DGR | 119.243 | 3 | 39.748 | .799 | .503 | |
| RGR | 195770.129 | 3 | 65256.710 | 1.434 | .251 | |
| Treatment * Salinity | SGR | 2.654 | 9 | .295 | .523 | .847 |
| DWG | .040 | 9 | .004 | .888 | .546 | |
| DGR | 397.549 | 9 | 44.172 | .888 | .546 | |
| RGR | 417441.510 | 9 | 46382.390 | 1.019 | .446 | |
| Error | SGR | 18.038 | 32 | .564 | ||
| DWG | .159 | 32 | .005 | |||
| DGR | 1591.150 | 32 | 49.723 | |||
| RGR | 1456597.274 | 32 | 45518.665 | |||
| Total | SGR | 35.946 | 48 | |||
| DWG | .364 | 48 | ||||
| DGR | 3641.459 | 48 | ||||
| RGR | 3954290.471 | 48 | ||||
| Corrected Total | SGR | 24.842 | 47 | |||
| DWG | .218 | 47 | ||||
| DGR | 2178.859 | 47 | ||||
| RGR | 2132546.149 | 47 |