L-selenomethionine: a powerful antioxidant for commercial fish species

Aquaculture Magazine, July 2021

In intensive animal production, high daily weight gain and high feed efficiency are essential. However, high performance is associated with increased levels of stress. Stress – such as from high stocking density, pathogenic pressure and temperature – is associated with enhanced levels of reactive oxygen species (ROS) and linked to suboptimal antioxidant status. Selenium (Se), in this respect, is a very important essential trace element as it is a vital component of selenoenzymes (eg glutathione peroxidase, GPx) which play a role in reducing ROS and maintaining a healthy antioxidant status.

Selenium can be added to the diet in either inorganic or organic forms. The advantage of using organic selenium, specifically L-selenomethionine, is its ability to be incorporated directly, without conversion, into general body proteins as a methionine source. The incorporated selenium, in the form of L-selenomethionine, acts as a storage of selenium in the animal. This stored selenium ensures optimal supply, even during stressful periods.

Dietary L-selenomethionine supplementation is known to offer a way to reduce performance loss under stress, such as crowding conditions (Küçükbay et al. 2008). A recent study in Nile tilapia, performed at the Mahasarakham University in Thailand, showed increased performance, improved innate immune response and high protection against pathogenic pressure (Streptococcus agalactiae).

L-selenomethionine (Excential Selenium 4000, Orffa Additives BV, The Netherlands) was tested and validated by independent researchers around the world in peer-reviewed publications (eg Berntssen et al. 2018; Silva et al. 2019) and proven to be effective in increasing the selenium and antioxidant status of fish, even under challenging conditions. Using L-selenomethionine in your diets will result in improved performance, immune function and higher economical return for your aquacultural production!