In an attempt to combat stress in aquaculture animals, the Interdisciplinary CIIMAR is proposing a food supplement for fish that raises serotonin levels, among other benefits, acting as a ‘stress buffer’. The proposal follows on from the doctoral work of Diogo Peixoto and promises other advantages such as strengthening the immune system of these animals.
At a time when the world’s population is expected to exceed 9.8 billion by 2050, aquaculture has emerged as the answer to human food needs, with the sector growing at an above-average rate. However, aquaculture carries many challenges including maintain fish welfare.
Animal stress is one of the biggest challenges in the aquaculture sector. This stress is caused by transport, high animal densities, overfeeding, water quality and handling procedures such as selection and vaccination. It has an impact on animal welfare and can also reduce growth rates and resistance to disease. As well as compromising animal health, it also leads to high economic losses in the sector.
It was in this context that Diogo Peixoto, under the guidance of CIIMAR researcher Rita Azeredo, studied the advantages of supplementing the diet of farmed fish with tryptophan, an essential amino acid with the capacity to be metabolized into various compounds, including serotonin, which in humans is known as one of the “happiness hormones”.
The role of tryptophan in combating stress
“In aquaculture, diseases most often appear after the fish have been subjected to a stressful situation. There are several strategies to combat this problem, some more successful than others. In our laboratory we have used immunonutrition as a strategy to improve animal welfare,” explains Benjamín Costas, leader of CIIMAR’s Aquatic Animal Health team and principal investigator of the IMMUNAA project, funded by the Foundation for Science and Technology (FCT), where the PhD student’s work was integrated.
“The main aim of my PhD was to understand the role of tryptophan in the immune response of sea bass, especially during situations of inflammatory response and resistance to disease,” explains Diogo. To this end, different research strategies were applied, which coincided in the same conclusion: tryptophan supplementation can mitigate the negative effects of stress, keeping energy metabolism stable and generating happier and healthier animals. “As fish are unable to synthesize tryptophan internally, its supplementation in feed is essential,” adds the researcher.
To know more, check the press release here.
