“evaluation of the effect of tiptopp’s products in against acute hepatopancreatic necrosis disease (ahpnd) of penaeid shrimp (penaeus vannamei) (boone, 1931) in laboratory conditions”
Conclusion
Based on the results, the improvement of survival was observed in treatments T1 (AquaG 1 g/kg) and T3 (AquaG 4 g/kg). Therefore, the application of AquaG can be considered as a promising in-feed probiotic in shrimp farming and the optimization of AquaG needs to be considered before applying at the field levels.
Executive summary
TipTopp Aquaculture conducted a trial to determine the effectiveness of TIPTOPP’s novel products in mitigating the severity and impact of Early Mortality Syndrome/Acute Hepatopancreatic Necrosis Disease (EMS/AHPND) in shrimp (Penaeus vannamei).
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.
The trial consisted of 6 groups including T1 (AquaG 1 g/kg), T2 (AquaG 2 g/kg), T3 (AquaG 4 g/kg), T4 (Basal diet + Fermented Soybean), T5 (Negative control), and T6 (Positive control) with 4 replicates per group.
After 14 days of feeding period, survival rates of Treatment T1, T2, T3, T4, T5 and T6 were 92.00 ± 3.27a%, 92.00 ± 0.00a%, 93.00 ± 2.00a%, 92.00 ± 0.00a%, 93.00 ± 2.00a%, and 93.00 ± 2.00a%, respectively. There were not statistically significant differences among the groups, (P > 0.05).
After 10 days of post-challenge, survival rates of the Positive control was 10.73 ± 2.36b%. Survival rates of treatments T1, T2, T3, and T4 were 30.18 ± 14.33c%, 18.48 ± 7.43bc%, 56.16 ± 17.65d%, and 22.83 ± 20.51bc%, respectively. Meanwhile, survival rate of Negative control was 93.61 ± 4.08a% at the trial termination. This indicates that no cross-contamination happened in the Negative control.
Based on the results, the improvement of survival was observed in treatments T1 (AquaG1 g/kg) and T3 (AquaG 4 g/kg). Therefore, the application of AquaG can be considered as a promising in-feed probiotic in shrimp farming and the optimization of AquaG needs to be considered before applying at the field levels.
Table 1. Treatments definition of the trial
| No. | Treatment | Top-coating of Tiptopp AquaGut onto the pelleted feed (g/kg) | Tiptopp Pond | Challenge | |
| Before challenge (Day 1-14) | Challenge (Day 15) & Post-challenge (Day 16-26) | (g/m3/day) directly apply in water) | |||
| 1 | Negative control (T5) | 100% pelleted feed | 0.0 | None | |
| 2 | Positive control (T6) | 100% pelleted feed | 0.0 | AHPND (Immersion) |
|
| 3 | Treatment 1 (T1) | 1.0 | 1.0 | 1.0 | |
| 4 | Treatment 2 (T2) | 2.0 | 2.0 | 2.0 | |
| 5 | Treatment 3 (T3) | 4.0 | 4.0 | 4.0 | |
| 6 | Treatment 4 (T4) | 100% pelleted feed | 100% of feed replace by Fermented Soybean with Product B for 2-3 days until shrimp stop to die/disease mitigation, then the shrimp will be fed with mixture of Fermented Soybean and pellet feed at ratio 20% (200 g/kg dry feed) for every meal* | 1.0 | |
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
| Variables | Treatment T1 | Treatment T2 | Treatment T3 | Treatment T4 | Treatment T5 | Treatment T6 |
| pH | 28.04 ± 0.19a | 28.03 ± 0.18a | 28.04 ± 0.18a | 28.04 ± 0.18a | 28.05 ± 0.20a | 28.05 ± 0.18a |
| DO (ppm) | 6.21 ± 0.13a | 6.20 ± 0.17a | 6.20 ± 0.13a | 6.18 ± 0.12a | 6.20 ± 0.14a | 6.20 ± 0.15a |
| Temp (oC) | 8.01 ± 0.06a | 8.02 ± 0.08a | 8.02 ± 0.07a | 8.03 ± 0.09a | 8.04 ± 0.08a | 8.05 ± 0.08a |
| TAN (ppm) | 1.14 ± 0.90a | 1.29 ± 0.95a | 1.14 ± 0.90a | 1.29 ± 0.95a | 1.29 ± 0.95a | 1.43 ± 1.13a |
| Nitrite (ppm) | 2.57 ± 1.62a | 2.57 ± 1.62a | 2.71 ± 1.60a | 2.57 ± 1.81a | 2.57 ± 1.62a | 2.57 ± 1.62a |
| Alkalinity (ppm) | 152.86 ± 4.88a | 155.71 ± 5.35a | 154.29 ± 5.35a | 155.71 ± 5.35a | 154.29 ± 5.35a | 155.71 ± 5.35a |
Values are presented as mean ± standard deviation. The same letters on the same row are presenting for not 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=4; P > 0.05)
Fig 2. Survival rate at the termination day (Day 10th of post-challenge) (Values are presented as Mean ± SD; n=4; 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 EMS/AHPND and the final survival rate was significantly higher than other treatments (93.61 ± 4.08a%). This indicated that the trial set up was acceptable and no cross-contamination happened to the Negative control.
Survival of treatments T1 (AquaGut 1 g/Kg) (30.18 ± 14.33c%) and T3 (AquaGut 4 g/Kg) (56.16 ± 17.65d%) had significantly higher than Positive Control (10.73 ± 2.36b%), (P < 0.05) (Fig. 2).
Fig 3. Survival rate throughout the challenge and post-challenge
1. Gross signs of EMS/AHPND
Fig 4. Healthy shrimp in negative control (brownish HP, full stomach and gut tract)
Fig 5. EMS-infected shrimp in positive control (pale, atrophic HP and empty gut tract)
