Abstract: Background and Objective: Adaptogens are plant substance that is known to enhance the productivity of animals mainly through their stress mitigating effects and hence the present study was undertaken with the main purpose to evaluate the effect of phytogenic feed additive (PHFA) on growth performance parameters in Litopenaeus vannamei under field conditions. Materials and Methods: The experimental shrimp for this study were post-larvae 10 (PL 10) and 112,000 shrimps were reared in two ponds (9.6×40×1.2 m). One pond served as the control group and was fed with a basal diet, the other pond was considered as a PHFA group fed with a basal diet plus PhytoceeTM (2 kg/ton). The water quality parameters such as dissolved oxygen, temperature, pH, total ammonia nitrogen and nitrites were measured every day. Salinity was measured every 3 days. Litopenaeus vannamei shrimps were fed with respective diets for 104 days. Results: The total body weight (kg), FCR and survival rate (%) exhibited by control and PHFA groups were 1,108 & 1,145, 1.173 & 1.135 and 91.01 & 94.05, respectively. Results revealed that body weight (kg), FCR and survival rate (%) of L. vannamei were improved following the addition of PHFA at 2 kg/ton as compared to the control group. This could be due to the impact of individual ingredients which was already known to have adaptogenic, antioxidant and immunity-booster property. Conclusion: In conclusion, the addition of PHFA at the dose level of 2 kg/ton of feed could be recommended for the augmentation of the growth performance parameters of L. vannamei.
INTRODUCTION
Litopenaeus vannamei is one of the economic aquatic animals as well as the high market demand species among the faster-growing species. During the past decades, the white shrimp culture industry has changed rapidly from smallholders to an intensive industry with high stocking density to achieve high levels of production performance, which became a potential stressor to the animals causing disease outbreaks. In recent years, shrimp culture techniques and management practices have evolved, however certain infectious diseases and their associated mortality poses threat to the industry. The stress due to the altered temperature, salinity shifts, heavy metal toxicity, viral infection and various other pathogenic microorganisms are the crucial factors for shrimp-intensive farms that led to health deterioration, reduced performance and productivity1.
Stress is known to trigger parasitic diseases as well as a predisposing factor to non-infectious conditions such as swim bladder stress syndrome, coagulated yolk disease and various skeletal disorders. These stressors affect the growth and productivity of aquaculture animals1. Adaptogens are plant substances known to mitigate the burden of stress in animals. Various plants like Withania somnifera, Ocimum sanctum, Panax ginseng, Tinospora cordifolia, Emblica officinalis, Bacopa monnieri, Rhodiola species and Terminalia chebula has been reported to be adaptogenic2. In that context, a phytogenic feed additive (PHFA) is selected as it is known to possess adaptogenic, anti-stressor, hepatoprotection and immunomodulatory properties. Moreover, PHFA possesses a broad range of pharmacological and clinical benefits for the protection and restoration of health in poultry birds3. Furthermore, PHFA enhances the endurance and immune response of white shrimps for protection against WSSV and salinity stress4.
With these viewpoints, this study was conducted to evaluate the effect of PHFA on growth performance parameters in Litopenaeus vannamei under field conditions.
MATERIALS AND METHODS
Study area: The study was conducted in white shrimp culture at Yancheng, Jiangsu province, China from August to November, 2021 (104 days). PhytoceeTM is a PHFA developed by Natural Remedies Private Limited, Bengaluru, which was composed of dried powder of Withania somnifera stems and fruits of Emblica officinalis and whole plant of Ocimum sanctum. The formulation was standardized to contain a
known quantity of polyphenols and gallic acid. The experimental shrimp for this study was post-larvae 10 (PL 10) and 112,000 shrimps were reared in two ponds (9.6×40×1.2 m). One pond was served as a control group and fed with a basal diet, the other pond was considered as a PHFA group fed with a basal diet plus PhytoceeTM (2 kg/ton). The water quality parameters such as dissolved oxygen (>4 mg L–1), temperature (28±1.0°C), pH (7.80-8.50), total ammonia nitrogen (<0.05 mg L–1) and nitrites (<0.8 mg L–1) were measured every day. Salinity (11 ppt) was measured every 3 days. Litopenaeus vannamei shrimps were fed with respective diets for 104 days.
RESULTS
The results of the effect of PHFA on growth performance parameters in L. vannamei was represented in Table 1. Results revealed that body weight (kg), FCR and survival rate (%) of L. vannamei were improved following the addition of PHFA at 2 kg/ton as compared to the control group. The total body weight (Kg), FCR and survival rate (%) exhibited by the control and PHFA group were 1,108 and 1,145, 1.173 and 1.135 and 91.01 and 94.05, respectively.
DISCUSSION
The present study was designed to evaluate the effect of PHFA on growth performance parameters in Litopenaeus vannamei under field conditions. Results of the field trial depicted that body weight (kg), FCR and survival rate (%) of L. vannamei were improved following the addition of PHFA at 2 kg/ton as compared to the control group. The observed higher body weight gain with lower feed consumption and mortality percentage was highly commercially significant since the trial was performed in field conditions. These results could be attributed to the adaptogenic, immunomodulatory and antioxidant activities of individual herbal ingredients present in the PHFA.
Literature reports evidenced that the beneficial effects of plant products are reducing the stress condition, serving as an appetizer, rendering antimicrobial activity as well as stimulating the immune system5,6. Herbal preparation plays a pivotal role in controlling diseases by exhibiting their antioxidant and antimicrobial activity7. Moreover, Indian medicinal plants possess antioxidant and immunomodulating properties8. The main advantage of herbal products was cost-effective with better accuracy in comparison with chemotherapeutic agents and provide a helpful solution to most of the problems that the aquaculture industry is facing today9.
| Table 1: | Effect of PHFA on growth performance parameters in L. vannamei | ||
|
Control |
PHFA |
Commercial | |
| Parameters |
group |
group |
significance |
| Stocking density (Nos) |
56,000 |
56,000 |
- |
| Feed consumption (kg) |
1,300 |
1,300 |
- |
| Final body weight (kg) |
1,108 |
1,145 |
37 Kg higher gain |
| Quantity harvested (Nos/kg) |
46 |
46 |
- |
| Feed conversion ratio (FCR) |
1.173 |
1.135 |
38 g less feed intake |
| Survival rate (%) |
91.01 |
94.05 |
3% more survival |
| The observed higher body weight gain (37 Kg) with lower feed consumption (38 g) and mortality percentage (3%) were highly commercially significant, as the trial was performed in field conditions | |||
To ease the problems, herbs were supplemented along with diets as a mixture or as an individual supplement to the shrimps10.
Withania somnifera is known to improve swim endurance, reduce stress-induced cortisol concentrations, prevent stress-induced ulcers and improve immunity in animals11. Withania somnifera has been shown to improve growth, haemato-biochemical response and disease resistance of Labeo rohita against Aeromonas hydrophila infection12. Furthermore, Laltlanmawia et al.12 reported that the inclusion of 1.0% W. somnifera root extract and L-ascorbic acid combination in the diet showed the immunostimulatory effect and attenuated the effect of multiple stressors viz. low pH and waterborne iron toxicity in Labeo rohita fingerlings.
Tiwari et al.13 reported the beneficial role of O. sanctum on a Clarias batrachus (Linn.) in augmenting immunity, growth and survivability. Various research investigators revealed that the anti-stress active principles of O. sanctum are believed to be Ocimumosides A and B and Ocimarin14-16.
Sharma et al.17 reported that E. officinalis reduces the number of free radicals and the extent of cellular damage and this antioxidant potential of E. officinalis could be attributed to the polyphenolic contents present in the extracts facilitating conjugation with free radical species. Furthermore, several research investigators reported the multiple effects of pharmacological and immunomodulatory properties of E. officinalis18. The above literature support as well as the results demonstrated that this polyherbal formulation has the potential to improve the overall productivity of L. vannamei by mitigating the impact of environmental stress in shrimp.
CONCLUSION
PHFA addition at the dose level of 2 kg/ton could augment the body weight, enhances survivability and improves the FCR of L. vannamei. These conducive effects of PHFA could be attributed to the antistress, immunomodulatory and antioxidant, properties of the phytoactive present in individual herbal ingredients in PHFA. Therefore, the addition of PHFA at the dose level of 2 kg/ton of feed could be recommended for the augmentation of the growth performance parameters of L. vannamei.
SIGNIFICANCE STATEMENT
Adaptogens are planting substances known to enhance the productivity of animals through mainly their stress-mitigating effects. Hence, in the present study, we aimed to assess the effect of PHFA on growth performance parameters in Litopenaeus vannamei. This study revealed the scientific fact that the addition of polyherbal formulations having stress-mitigating effects could play a pivotal role in the augmentation of productivity of L. vannamei.