Metabolic programming in juveniles of the whiteleg shrimp ( Litopenaeus vannamei ) linked to an early feed restriction at the post-larval stage

In this study, the concept of metabolic programming has been tested for the first time in whiteleg shrimp (L. vannamei). Shrimp were raised under a 70% feed restriction during the post-larval stage over three days and compared to a control group. After 46 days, shrimp were challenged with 3 diets showing different nitrogen free-extract: crude protein ratios (1.5, 1.0 and 0.7) for 70 days. In order to test the existence of metabolic programming, we analyzed shrimp growth performance as well as mRNA levels of different metabolic and digestive actors after the stimulus, and also before and after the challenge. No direct effects of the stimulus were observed for several digestive and metabolic actors, except for the trypsin mRNA (lower in the feed-restricted group, probably linked to a decrease in dietary protein intake). As expected, significant effects associated with the diet challenge were detected for shrimp performance, i.e., growth was lower in shrimp fed with reduced levels of dietary proteins. More interestingly, some effects linked to the nutritional history were also detected showing an improved growth performance for shrimp previously restricted at the post-larvae stage. After the dietary challenge, significantly lower mRNA levels for hepatopancreatic genes involved in digestion (lipase, preamylase and trypsin), amino acid metabolism (gs), energy metabolism (cox VI b) and glucose metabolism (lvglut 1, lvglut 2 and pk) were found in restricted shrimp. The link between an enhanced growth performance and these molecular markers in early feed restricted shrimp requires further studies. Overall, our study has demonstrated for the first time that shrimp can be programmed by an early nutritional stimulus. This will allow the development of new feeding strategies in shrimp for sustainable aquaculture