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Activated zinc oxide: An innovative nutritional approach to reduce WSSV-induced mortality in shrimp Benedikt Hein, Torben Liermann, Provita Supplements, Martin Rimbach, ISF GmbH
One of the most important fatal diseases in shrimp production is the White Spot Syndrome Virus (WSSV). WSSV is a virus causing high mortality rates, up to 100.0 % within 5 to 7 days and was first reported during the early 90s. Infected shrimp can be recognized by a loose cuticle with white spots (Lightner, 1996; Lin et al., 2011). Even though WSSV has been known for numerous years, shrimp producers still face enormous economic risks from high mortality rates due to the virus, especially during the cooler seasons. Treatment options against WSSV are still poorly developed and ineffective, mainly based on biomolecules like DNA or RNA vaccines, protein-based antigens and antibodies as well as herbal products (Feng et al., 2017). Furthermore, lower stocking densities have proven to reduce WSSV caused mortalities (Raja et al., 2015). While the above-
mentioned methods may be effective, they are neither very practical nor viable economically for shrimp producers. For this reason, we investigated the effect of feeding diets including different levels of our activated zinc oxide (MAXACTIVAT/Zn) on the susceptibility of WSSV-induced mortality in shrimp (Penaeus vannamei). Previous R&D work has already shown the positive influence of MAXACTIVAT/Zn against bacterial pathogens such as E. coli in calves and piglets. MAXACTIVAT/Zn (aZnO) has also shown a comparable greater impact on reducing bacterial growth in vitro compared with conventional Zn oxide (Hoffmann et al., 2019). The above-mentioned effects are often concluded to be related to an improvement of the barrier function of the gut mucosa (Li et al., 2001; Sales, 2013). This in turn allows the assumption that this also
Figure 1. Total mortality over the experimental period of the different dietary groups, IMAQUA (2020). *significant at p < 0.05
Aquafeed: Advances in Processing & Formulation Vol 13 Issue 3 2021
