“Effects of application of tiptopp’s probiotics on tolerance against muscle necrosis disease induced by vibrio harveyi (non-luminescent bacteria) on penaeid shrimp (panaeus vannamei)”
Conclusion
Based on the results, survival rates of shrimp in treatment T1 (1g/kg TG + 1g/m3 TP) was the best treatment in this trial in terms of survivability improvement. In general, the test products were demonstrated their effectiveness on improving survivability and enhancing shrimp tolerance with muscle necrosis disease under laboratory conditions.
Executive summary
TipTopp Aquaculture conducted a trial to determine the effectiveness of TipTopp’s probiotics on tolerance against Vibrio harveyi (Non-Luminescent bacteria) in penaeid juveniles (Penameus vannamei) (1Holthuis, 1980).
The trial lasted 26 days including an adaption period for 01 day, 14 days of feeding period, 01 day of challenge, and following 10 days of post-challenge.
Tiptopp AquaG (TG) and Tiptopp Pond (TP) were used for the trial.
The trial consisted of 5 groups including T1 {(Diet A_1g/kg TG + 1g/m3 TP), T2 (Diet B_2g/kg TG + 2g/m3 TP), T3 (Diet C_4g/kg TG + 4g/m3 TP), T4 (Positive control, without TG & TP), and T6 (Negative control, without TG & TP) with 5 replicates per group.
After 14 days of feeding period (pre-challenge), survival rates of Treatment T1, T2, T3, T4, and T5 were 85.60 ± 2.19a%, 84.80 ± 3.35a%, 86.40 ± 2.19a%, 85.60 ± 3.58a%, and 86.40 ± 2.19a%, respectively. There were not statistically significant differences among the groups (P > 0.05).
After 10 days of post-challenge, survival rate of the Positive control was 43.71 ± 17.31b%. Survival rates of treatments T1, T2, and T3 were 58.64 ± 25.51b%, 48.40 ± 16.88b%, and 47.62 ± 24.97b%, respectively. Meanwhile, survival rate of Negative control was 89.74 ± 1.90a% which is much higher than the challenged groups at the trial termination. This indicates that no cross-contamination happened in the Negative control.
Based on the results, survival rates of shrimp in treatment T1 (1g/kg TG + 1g/m3 TP) was higher than the positive control and the other treatments at the end of the trial. However, there was no a statistically significant difference among the treatment groups versus the positive control due to high variation within a group (P>0.05). In general, the test products were demonstrated their effectiveness on improving survivability and enhancing shrimp tolerance with muscle necrosis disease under laboratory conditions.
Table 1. Treatments definition of the trial
| No. | Treatment | No. Reps | Feed |
Density (Shrimp/tank) |
Challenge (V. harveyi) |
| 1 | Treatment T1 | 5 | 1g/kg TG + 1g/m3 TP | 25 | Yes |
| 2 | Treatment T2 | 5 | 2g/kg TG + 2g/m3 TP | 25 | Yes |
| 3 | Treatment T3 | 5 | 4g/kg TG+ 4g/m3 TP | 25 | Yes |
| 4 | Pos. Ctrol T4 | 5 | Control diet | 25 | Yes |
| 5 | Neg. Ctrol T5 | 5 | Control diet | 25 | No |
1. Results
1.1. Water quality parameters
Throughout 26 days of the trial, water quality parameters were recorded and presented in Table 2.
Table 2. Water quality parameters during the trial
| Treatment | T1 (Diet A) |
T2 (Diet B) |
T3 (Diet C) |
T4 (Pos. ctrl) |
T5 (Neg. ctrl) |
| Temp (oC) | 27.44 ± 0.23a | 27.42 ± 0.20a | 27.45 ± 0.17a | 27.41 ± 0.19a | 27.43 ± 0.19a |
| DO (mg/L) | 6.18 ± 0.06a | 6.16 ± 0.06a | 6.18 ± 0.06a | 6.18 ± 0.06a | 6.18 ± 0.06a |
| pH | 8.02 ± 0.06a | 8.02 ± 0.07a | 8.02 ± 0.06a | 8.02 ± 0.08a | 8.03 ± 0.06a |
| Alkalinity (ppm) | 137.50 ± 7.07a | 138.75 ± 6.41a | 138.75 ± 8.35a | 142.50 ± 7.07a | 137.50 ± 4.63a |
| TAN (ppm) | 0.50 ± 0.27a | 0.50 ± 0.27a | 0.63 ± 0.35a | 0.63 ± 0.35a | 0.31 ± 0.26a |
| Nitrite (ppm) | 3.00 ± 1.93a | 3.13 ± 1.96a | 2.88 ± 1.81a | 3.00 ± 1.93a | 2.38 ± 1.30a |
| Sanility (ppt) | 20.00 ± 0.00a | 20.00 ± 0.00a | 20.00 ± 0.00a | 20.00 ± 0.00a | 20.00 ± 0.00a |
Values are presented as mean ± standard deviation. The same letters on the same row are presented not statistically significant differences (p > 0.05).
1.2. Survival rate
During the trial, survivors were counted daily to assess the estimated survival rate. Survival rate of shrimp after pre-challenge and post-challenge were shown in Figure 1 and Figure 2.
Fig 1. Survival rate after 14 days of the pre-challenge (Values are presented as Mean ± SD; n=5; P > 0.05)
Fig 2. Survival rate at the termination day (Day 10th of post-challenge) (Values are presented as Mean ± SD; n=5; P < 0.05)
After 14 days of pre-challenge, there was no statistically significant difference in terms of survival rate among treatments (P>0.05) (Fig. 1).
During the challenge and post-challenge, shrimp in the negative control did not show any clinical signs of the disease and final survival rate was significantly higher than other treatments (89.74± 1.90a %). This indicated that the trial set up was acceptable and no cross-contamination happened to the negative control.
Survival rates of shrimp in treatments T1 (1g/kg TG + 1g/m3 TP) were higher than the positive control and other treatments at the end of the trial. However, there was no a statistically significant difference among the treatment groups versus the positive control due to high variation within a group (P>0.05).
1. Gross signs of muscle necrosis disease induced by V. harveyi
