Aquaculture Europe 2021

October 4 - 7, 2021

Funchal, Madeira

Add To Calendar 06/10/2021 15:50:0006/10/2021 16:10:00Europe/LisbonAquaculture Europe 2021GENETIC CORRELATIONS BETWEEN PROCESSING TRAITS AND INDIVIDUAL FEED EFFICIENCY IN A GILTHEAD SEA BREAM Sparus aurata COMMERCIAL LINEFunchal-HotelThe European Aquaculture Societywebmaster@aquaeas.orgfalseDD/MM/YYYYaaVZHLXMfzTRLzDrHmAi181982

GENETIC CORRELATIONS BETWEEN PROCESSING TRAITS AND INDIVIDUAL FEED EFFICIENCY IN A GILTHEAD SEA BREAM Sparus aurata COMMERCIAL LINE

A. Bestin*a, M. Bessona, A. Vergnetd, F. Allald, F. Clotac,d, S. Carioub, J.-S. Bruantb, P. Haffraya, M. Vandeputtec,d

a SYSAAF (French Poultry and Aquaculture Breeders Technical Centre), 35042 Rennes, France

b FMDS (Ferme Marine du Soleil), 17840 La Brée-les-Bains, France

c INRAE, GABI, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France

d MARBEC, University of Montpellier, CNRS, Ifremer, IRD, 34192 Palavas-les-Flots, France

E-mail: anastasia.bestin@inrae.fr

 



Introduction

In fish farming, costs of feed range from 30 to 70% of the total production cost (Doupé and Lymbery, 2004; Kolstad et al., 2004). The gilthead sea bream (Sparus aurata) is the most important species of Mediterranean aquaculture, with 228,000 tons produced in 2018 (FAO, 2020). Feed efficiency is a key driver of profitability in this species, and its improvement would contribute to reduce environmental impacts of farming. Selective breeding could be used to improve this trait, provided individual phenotypes of feed efficiency are available. An experimental setting was implemented for this purpose at Ifremer (Palavas-les-Flots, France) and tested in a sea bream population of the FMDS line as described in Besson et al. (2019) for sea bass. We estimated then the heritability of individual feed efficiency, production traits and their genetic correlations.

Material and Methods

The cohort was derived from the FMDS breeding program in September 2018, using 61 sires and 28 dams mated in a partial full factorial design. The fertilized spawn of each dam was incubated separately. Larvae were transferred and reared in a single tank to minimize environmental variance. About 800 fish (~2.7g, at random) were individually tagged at 91 days post hatching (dph) and sent to Ifremer to undergo the individual feed efficiency trial, starting at 161 dph. About 1530 of their sibs were tagged and sent in a sea-cage for growing from 128 to 432 dph. All progeny and their parents were tissue-sampled for DNA parentage assignment (cage-reared fish) or for genotyping with the DlabChip 57K SNP chip for fish tested for individual feed efficiency.

From the feed efficiency trial we obtained the individual residual body weight gain (rBWG) as a proxy of individual feed efficiency according to this formula:

MBW is the initial metabolic body weight of the fish (BW0.8). β0 is the regression intercept, β1 is the partial regression coefficient of an animal’s BWG on its metabolic weight and β2 is the partial regression coefficient of an animal’s BWG on IFI, its cumulated feed intake during the trial period.

From the slaughtering after sea-cage rearing we obtained Harvest Body Weight (HBW), Fat content (Distell® FatMeter, Scotland), gutted carcass weight and headless and gutted carcass weights, which were regressed on HBW to obtain phenotypic and genetic parameters for residual headless and gutted carcass weight (rHC_W) and residual carcass weight (rC_W) as surrogates for the yield of those body parts relative to HBW.

Heritabilities and genetic correlations for all traits were computed based on multivariate linear mixed animal models fitted by restricted maximum likelihood in AIREMLF90 using a single-step approach, using genomic information for fish with individual feed efficiency phenotypes and pedigree information for cage-reared fish (Misztal et al., 2002).

Results and Discussion

As shown in Table 1, individual feed efficiency is a heritable trait in sea bream (0.23 ± 0.09). None of the processing traits measured at slaughtering in the sea cage was significantly genetically correlated with feed efficiency. Nonetheless, there might be a tendency where leaner fish have a higher feed efficiency (genetic correlations of -0.20 with Fat and +0.55 with rHC_W). Efficient fish may also be the fastest growers (genetic correlation of +0.22 between harvest body weight and feed efficiency).

Conclusion

Individual feed efficiency measured in a commercial line of sea bream is a heritable trait, which can thus be improved by selective breeding. This first result in sea bream supports the study by Besson et al. (2019) on sea bass in which individual feed efficiency traits measured in aquaria were also heritable. This trait is positively genetically correlated with growth and processing traits, which would enable selection on feed efficiency without impairing other production traits of interest.

Acknowledgement

The data presented here were obtained in the PerformFISH project which received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 727610. This output reflects the views only of the authors, and the European Union cannot be held responsible for any use which may be made of the information contained therein.

References

Besson, M., Aubin, J., Komen, H., Poelman, M., Quillet, E., Vandeputte, M., Van Arendonk, J.A.M., De Boer, I.J.M., 2016. Environmental impacts of genetic improvement of growth rate and feed conversion ratio in fish farming under rearing density and nitrogen output limitations. J. Clean. Prod. 116, 100–109. https://doi.org/10.1016/j.jclepro.2015.12.084

Besson, M., Allal, F., Chatain, B., Vergnet, A., Clota, F., Vandeputte, M., 2019. Combining Individual Phenotypes of Feed Intake With Genomic Data to Improve Feed Efficiency in Sea Bass. Front. Genet. 10, 1–14. https://doi.org/10.3389/fgene.2019.00219

Doupé, R.G., Lymbery, A.J., 2004. Indicators of genetic variation for feed conversion efficiency in black bream. Aquac. Res. 35, 1305–1309.

Kolstad, K., Grisdale-Helland, B., Gjerde, B., 2004. Family differences in feed efficiency in Atlantic salmon (Salmo salar). Aquaculture 241, 169–177.

Misztal, I., Tsuruta, S., Strabel, T., Auvray, B., Druet, T., Lee, D.H., 2002. BLUPF90  and related programs (BGF90), in: Proceedings of the 7th WCGALP. Montpellier, pp. 28–071.