Pompano Fish Lab Report

Fig. 4. Mean (± SEM) weight of pompano fish (g) fed experimental diets on days 0, 14, and 28 of the trial. Treatment diets included the basal diet, or the basal diet with 0.05% Macrogard (D0.05), 0.10% Macrogard (D0.10) and 0.20% Macrogard (D0.20) supplementation. Data are presented as the means ± SEM. Different letters are significantly different between treatments at each time point.

Table 4. Growth performance of pompano fish fed different concentration β-glucan in the diet for 28 days. Data are presented as the means ± SEM. Values in a row with different superscripts differ significantly (P < 0.05).

Diets D0.00 D0.05 D0.10 D0.20
Initial weight (g) 30.53 ± 0.51 30.49 ± 0.62 31.00 ± 0.53 30.83 ± 0.73
Initial length (mm) 101.46
± 0.60 102.28 ± 0.63 104.04 ± 0.75 102.08 ± 0.45 Day 14
Growth (g wk-1) 3.19 ± 0.23a 5.76 ± 0.23b 4.49 ± 0.51ab 4.15 ± 1.33ab
DGC (% d-1) 1.49 ± 0.12a 2.59 ± 0.07b 2.04 ± 0.24ab 1.87 ± 0.60ab
Biomass (g/tank) 325.24 ± 14.29a 427.36 ± 25.24b 388.86 ± 19.46b 376.06 ± 17.04b
HIS (%) 1.08 ± 0.09 1.25 ± 0.13 1.11 ± 0.06 1.12 ± 0.11
VSI (%) 5.80 ± 0.14a 6.45 ± 0.23b 6.47 ± 0.32b 6.27 ± 0.25ab Day 28
Growth (g wk-1) 3.79 ± 0.70a 6.19 ± 0.31b 6.20 ± 0.77b 6.49 ± 0.87b
DGC (% d-1) 1.66 ± 0.30a 2.57 ± 0.13b 2.53 ± 0.27b 2.63 ± 0.31b
Biomass (g/tank) 399.96 ± 24.2a 530.06 ± 19.67b 514.36 ± 46.13b 512.48 ± 39.11b
HIS (%) 1.07 ± 0.09a 1.40 ± 0.08b 1.31 ± 0.07b 1.22 ± 0.04ab
VSI (%) 6.01 ± 0.02a 6.67 ± 0.07b 6.40 ± 0.18b 6.38 ± 0.07b
* VSI: Viscerosomatic index; HIS: Hepatosomatic index
Means with different superscripts in row are significantly different

At days 14 and 28, biomass yield of pompano in fed BG diet were significantly higher than fish fed control diet (P ≤ 0.041).
At the end the experiment (day 28), highest biomass yield was in those groups of pompano fish fed D0.05, D0.10 and D0.20, which were significantly higher than fish fed control diet (P ≤ 0.012).

At day 14, HIS of fish did not significantly differ between treatments (P ≥ 0.238), while at day 28 HIS of fish fed D0.05 and D0.10 were significantly higher than HIS of fish fed control (P ≤ 0.040). At days 14, VSI was significantly higher in fish fed D0.05 and D0.10 compared to fish fed control (P ≤ 0.039), but this values did not differ significantly between fish fed D0.20 and fish fed control (P ≥ 0.087). At day 28, all groups of fish fed BG had VSI higher than fish fed control diet (D0.00) (Table 2).

3.7 Survival rate
At the end of the experiment (day 28), survival rates of pompano fish ranged from 86.11% in fish fed D0.00 to 91.66% in fish fed D0.05 (Figure 5). The highest survival was for fish fed diets D0.05 (91.66%) followed by the fish fed D0.10 and D0.20 (90.27% and 89.58%, respectively). The survival rate of fish was not significant difference between the diet treatments (P = 0.083).

Fig. 5. Survival rate of pompano fish fed β-glucan in the diet at days 14 and 28. Data are presented as mean ±
SEM.

3.8 Survival of pompano fish exposed to ammonia stress
After 28 days pre-feeding with BG-supplemented diets, the ammonia challenge test was performed for 96 hours. Cumulative mortalities of pompano fish fed different levels of β-glucan challenged to the ~1mg L-1 NH3-N stress for 96 h were plotted using Kaplan-Meier curves and followed by log-rank comparison. The highest survival rate was in fish fed diets D0.10 and D0.05 followed by fish fed D0.20, which was significantly higher than fish fed control diet (D0.00) (P ≤ 0.011). Survival rates of fish fed diets D0.05, D0.10 and D0.20 were not significant difference (P = 0.241).

Fig. 6. Kaplan-Meier curves for pompano fish fed β-glucan diet exposed to ammonia for 96 h.

Pompano fish fed β-glucan in the diet had significantly lower risk value when exposed to ammonia stress. When exposed to ammonia stress, relative risk in groups of fish fed diets D0.05, D0.10 and D0.20 were as follow: D0.05: 0.476 (95% CI: 0.290 to 0.783), D0.10: 0.286 (95% CI: 0.141 to 0.581) and 0.6190 (95% CI: 0.416 to 0.922). When exposed to ammonia toxicity, the relative risk of pompano fish fed BG diet were significantly lower in comparison to fish fed control diet (P ≤ 0.018). Similar trend for the odd ratio value when exposed to ammonia, in compared to fish fed control diet (D0.00), pompano fish fed BG diets D0.05, D0.10 and D0.20 had odd ratio value were 0.102 (95% CI: 0.023 to 0.438), 0.048 (95% CI: 0.010 to 0.218) and 0.169 (95% CI: 0.040 to 0.721), respectively, which significantly differ from fish fed control diet (D0.0) (P ≤ 0.016). (Figure 6)

3.9 Body Composition of pompano fish fed BG diets Fig. 7. Protein content in the flesh of pompano fish fed different levels of β-glucan

At day 28, dietary β-glucan supplementation significantly affected fish body composition (Fig.
7 and 8). Crude protein content increased significantly with the increasing levels of β-glucan supplementation, and the highest protein content was in fish fed diets D0.05 and D0.10, which was significantly higher than protein content in fish fed D0.00 (P ≤ 0.034). However, there was no significant difference in protein content in fish among the three levels of β-glucan supplementation (P ≥ 0.057). also, no significant difference in protein content in fish fed D0.20 and D0.00 (P = 0.547). Dietary β-glucan significantly reduced lipid content in the muscle of pompano fish in comparison to those fish fed diet D0.00 (P ≤ 0.029), however, lipid contents in fish fed with β-glucan supplementation did not differ significantly from each other (P ≥ 0.221). (Figures 7 and 8)

Fig. 8. Lipid content in the flesh of pompano fish fed different levels of dietary β-glucan

3.10 Correlations between dietary β-glucan and growth, haematological index, microflora and immune response of pompano fish at days 14 and 28.

Table 5. Pearson correlation (r) matrix among dietary β-glucan inclusion (%) and growth performance, haematological index, intestinal microflora and immune response of pompano fish at days 14 and 28. Day 14 Day 28 r Sig. r
Sig.
Mean weight (g) 0.342 0.165 0.578* 0.012
Weight gain (g wk-1) 0.349 0.155 0.545* 0.019
DGC (% d-1) 0.337 0.171 0.514* 0.029
Survival (%) 0.201 0.369 0.197 0.379
Biomass (g tank-1) 0.421 0.082 0.506* 0.032
RBC 0.300 0.154 0.330* 0.037
WBC 0.573** 0.003 0.342* 0.031
WBC : RBC (%) 0.490* 0.015 0.348* 0.032
Monocyte -0.519** 0.001 -0.412* 0.015
Lymphocyte 0.395* 0.010 0.384* 0.025