Enterocytozoon hepatopenaei (EHP) is one of the major threats to shrimp farming in S outh East Asia. Its life cycle, includes a spore phase which makes it particularly challenging to control and eradicate.
After screening various plant molecules with potential effect on EHP sporulation, TECHNA designed an additive called EHPROTECT that prevent spore germination, thus reducing severity and occurrence of EHP outbreaks.
A challenge trial was held at ShrimpVet facilities, to evaluate the effect of EHPROTECT on survival, growth and FCR of whiteleg shrimp (Litopenaeus vannamei ). The trial comprised four treatments:
EHP was collected from infected shrimp, standardized to create an inoculum, and coated onto the shrimp feed s after peletization. The feed’s EHP load was monitored to ensure exposure . EHP counts ranged from 1.7 x 10^6 to 5.44 x 10^6 spores . EHPROTECT was mixed with other ingredients during feed manufacturing. Trial was divided into 3 phases: 14 days pre challenge where shrimp consumed the additive followed by a 7 day challenge phase where treatments 2,3 and 4 received EHP spores through the feed and finally a 28 days observation phase to see the effects of EHP spore infection on shrimp survival and performances.
Each treatment was composed of six re plicate groups of 50 shrimp (mean initial weight: 1.59 g), maintained in 250 L tanks at a temperature of 27.9 ± 0.25° C.
The results showed a strong effect of EHP infection on all parameters, with a final survival lowered from 92% down to 71.7%, a FCR increased from 1.31 to 3.66 and a final weight almost divided by 2 (15.4 vs 7.9g) .
The inclusion of EHPROTECT mitigated the negative effects of EHP during this challenge, with a final weight of 9.2 and 11.5g and a FCR of 2.13 and 1.61 for the 2 and 4kg EHPROTECT treatment respectively. Survival was also improved at 79.3 and 86.7%.
In conclusion, this trial demonstrated the efficacy of EHPROTECT in limiting the effects of EHP outbreaks in challenge conditions . Positive effects were also seen on various farms in India, showing EHPROTECT as a promising solution against EHP.