@INRAE Bertrand Nicolas

A review of 20 years of rainbow trout breeding

Genetics for sustainable aquaculture: a review of 20 years of rainbow trout breeding

While fishing has reached its limits, the demand for fish is increasing every year. In this context, aquaculture constitutes an alternative, provided that it is sustainable while allowing a quality production. INRAE, the Aqualande group and its trout selection and reproduction company "les Sources de l'Avance", and the Syndicat des Sélectionneurs Avicoles et Aquacoles Français (SYSAAF) have carried out a review of a 20-year rainbow trout selection program conducted by the company. They compared the growth and feed requirements of trout from this program with those of non-selected trout. Their results, published in Aquaculture Reports, show that 17 to 20 percent less feed is now required for the same growth of the fish with the selected trout, thus reducing the environmental impact. A locally produced sustainable feed, without fish oil, fish meal or soy, was also tested on both groups of fish. Growth gains and nutritional qualities are maintained with this feed of the future. This original work on a global scale shows that genetic improvement and innovative feed development can be effectively combined to contribute to a more sustainable aquaculture.

Between 1997 and 2019, the Aqualande group conducted a genetic selection program for rainbow trout over 10 generations, based on the principles established by INRAE and SYSAAF. In parallel, non-selected rainbow trout from the same original population were kept. To evaluate the performance gain linked to the selection, INRAE, Aqualande and SYSAAF participated in the European collaborative research program AquaImpact during which they were able to compare the two groups of fish, selected and non-selected, for growth and morphology, as well as for fillet yield and lipid content. Based on INRAE's work, they also produced a sustainable feed, without fish oil or fish meal, and without soy to limit extra-European imports. This feed is produced with original ingredients from France and Europe, such as potato proteins or micro-algae. For 110 days, one part of the trout from both groups was fed with this feed, and the other part with a standard commercial feed, containing fish meal and fish oil.

The results show that the trout from the selection program need 17% to 20% less feed than the non-selected trout to achieve the same growth. In addition, their fillets have a higher lipid content, which improves their nutritional and taste quality. Whether fed the sustainable feed or the standard feed, trout in both groups grew equally well. The addition of microalgae in the formulation of the sustainable feed ensures the nutritional quality of the fillets, which contain as much long-chain omega-3 fatty acids[1] as fillets from trout fed the feed containing fish oil.

This study shows that breeding programs and the development of sustainable feeds are two important levers to reduce the environmental impact of farmed fish production and accelerate the transition to a more sustainable aquaculture.

See also

Press release INRAE (FRench)

REFERENCE

Marc Vandeputte, Geneviève Corraze, Jérôme Doerflinger, Florian Enez, Frédéric Clota, Frédéric Terrier, Mathilde Horat, Laurence Larroquet, Vincent Petit, Pierrick Haffray, Sandrine Skiba-Cassy, Mathilde Dupont-Nivet. Realised genetic gains on growth, survival, feed conversion ratio and quality traits after ten generations of multi-trait selection in rainbow trout Oncorhynchus mykiss, fed a standard diet or a “future” fish-free and soy-free diet. Aquaculture Reports Volume 27, December 2022, 101363, DOI : https://doi.org/10.1016/j.aqrep.2022.101363

Modification date : 14 September 2023 | Publication date : 17 October 2022 | Redactor : INRAE - Edition P. Huan