Effects of dietary supplementation with powder of Antarctic krill (Euphausia superba) on growth performance, body composition and color of Litopenaeus vannamei

To determine the application effect of Euphausia superba powder (PE) in shrimp culture, we designed five groups S0 group (No PE supplementation), S5 group, S10 group, S15 group, and S20 group (5%, 10%, 15% and 20% PE supplemented to the feed, respectively) for a 35-day experiment on Litopenaeus vannamei Body mass of (7.27±0.88) g. The effect of dietary supplementation with PE on the growth performance, body composition and color of L. vannamei were evaluated. The results show that: 1) PE supplementation improved the survival rate (SR) of L. vannamei significantly (P<0.05), and the final body mass (FBW), weight gain rate (WGR) and specific growth rate (SGR) of L. vannamei in S15 group were significantly higher compared with the other groups (P<0.05). 2) With the increase of PE supplementation, the crude fat content of L. vannamei increased gradually, and those in S10 group, S15 group and S20 group were significantly higher than that in S0 group (P<0.05). Additionally, the brightness (L^*) of the cephalothorax and the yellowness (b^*) of the carapace of L. vannamei decreased gradually, which were significantly lower than those in S0 group (P<0.05). 3) PE supplementation to the feed increased the astaxanthin content in the hepatopancreas and crustacean of L. vannamei significantly (P<0.05), and the effect was positively associated with PE supplementation. The expression level of the LVPBP75 related to body color was also positively correlated with PE supplementation. The results indicate that dietary supplementation with PE, especially with 15% PE, can improve the growth, astaxanthin content, body color as well as expression level of LVPBP75 of L. vannamei.