Sea Bass Market

In December 2020 I had the pleasure to participate in the EAAP congress. Although it would have been nice to visit the city of Porto for the first time, I had no such luck, due to the Covid-19 pandemic. Instead it became the first time for me participating in a virtual scientific congress. With me to the congress I brought a virtual poster on a trial studying the effects of Progut® on young sea bass. The virtual poster was actually a pre-recorded 3 minutes presentation.

Asian sea bass (Lates calcarifer) is a commercially important cultivated fish. It is omnivorous and euryhaline. Euryhaline is a fancy word meaning the fish can tolerate a wide range of water salinity. The trial was conducted in collaboration with Valaya Alongkorn Rajabhat University and Kasetsart University at a university contact farm, in Nakorn Pathom province, Thailand.

We studied the effect of dietary Progut®, Saccharomyces cerevisiae yeast hydrolysate, on the performance of young Asian sea bass, as previously the product has been shown to improve the performance of farm animals, such as chicken, pigs, calves and dairy cows. The experiment was carried out in earth ponds. Juvenile fish with a mean weight of 13 g were allocated into 12 net cages, 30 fish per cage, at a density of five fish/m3.

The three dietary treatments were a commercial-type feed without Progut® serving as a control treatment, and the same feed amended with either 0.15%, or 0.30% Progut®. Four replicate net cages were randomly allocated to each diet. The fish were fed three times per day at 3–5% of body weight for 8 weeks. The feed intake, weight gain, feed conversion ratio (FCR) and mortality of the fish were measured. At the end of the study, five fish per net cage were blood sampled for several immunity-related variables: white blood cell count, red blood cell count, hemoglobin, hematocrit, immunoglobulin M (IgM), lysozyme activity, and glutathione.

During the 8 weeks trial period, dietary Progut® addition significantly increased the average daily gain by 36%, specific growth rate by 17% on average, and the feed consumption of the fish by 28% on average. However it did not affect FCR. Progut® on both doses decreased the counts of red and white blood cells, whereas haematocrit was highest in the group receiving the higher dose of Progut®. The other immune variables were similar in all treatments.

In summary, Progut® supplementation increased feed intake and weight gain of young Asian sea bass, thus having a positive effect on fish performance. Further studies are needed to determine the optimal dosing level of Progut®, and also to evaluate the effects until harvestable size.

Read the survey of EAAP meeting by Dr. Hannele Kettunen.

REFERENCE: Eija Valkonen1, Hannele Kettunen1, Shah Hasan1, Juhani Vuorenmaa1, Srinoy Chumkam2, Orapint Jintasataporn3 (2020) Saccharomyces cerevisiae -hydrolysate improved performance of Asian sea bass. Abstract no 28.6 in: European Federation of Animal Science (EAAP) virtual meeting 1-4 December 2020. 1Hankkija Oy, FI-05800 Hyvinkää, Finland, 2 Faculty of Agricultural Technology, Valaya Alongkorn Rajabhat University, Pathum Thani, Thailand, 3Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok 10900, Thailand