Aquaculture Reports (Dec 2022)
Growth variables, feed efficacy, survival rate, and antioxidant capacity of European seabass (Dicentrarchus labrax L.) larvae treated with Coenzyme Q10 or lipoic acid
Abstract
A 30-day feeding trial was performed to assess the potential of the dietary supplementation of Coenzyme Q10 (CoQ10) and lipoic acid on acclimatized European seabass larvae with a preliminary weight and length of 2.7 mg and 12.42 mm (25 dph = days post-hatching). Seven experimental groups were fed on the basal micro-diet (56 % crude protein and 13 % crude lipid) without any supplement in the control group or with the addition of CoQ10 at levels of 5, 10, and 15 mg/kg or α-lipoic acid at levels of 50, 100, and 150 mg/kg, respectively. Larvae fed on a diet enriched with CoQ10 at levels of 5 and 10 mg/kg showed the highest values for final weight, weight gain, specific growth rate (SGR), the protein efficiency ratio (PER), and the lowest value for feed conversion ratio (FCR) as well as no morphological or histological abnormalities. Also, the group fed a diet supplemented with CoQ10 at 5 mg/kg gave the highest values for final length and survival. The survival rate ranged from 54.59 % to 79.82 % and the lowest rate was in the group fed a diet enhanced with lipoic acid at 150 mg/kg. Meanwhile, the lowest records for final weight, weight gain, protein efficiency ratio, and the presence of morphological and histological abnormalities were in groups fed on the control diet and with high levels of lipoic acids (100 and 150 mg/kg). Moreover, all lipoic acid groups showed deleterious signs in the histological structure of the intestine and liver. However, significantly lower values of catalase (CAT) and glutathione peroxidase (GPx) were found in the fish group fed on the basal diet, while the peak values were in groups fed on diets fortified with CoQ10 at 5 and 10 mg/kg. In addition, larvae fed CoQ10 at levels of 5 or 10 mg/kg performed better in terms of CAT and GPx activities than that fed lipoic acid at levels of 100 or 150 mg/kg. Furthermore, the control group displayed lower levels of insulin-like growth factor 1 (IGF-1), CAT, and GPx -related gene expressions while considerable upregulations of IGF-1 and GPx were noted in larvae groups fed on diets improved with CoQ10 at levels of 5 or 10 mg/kg and lipoic acid at 50 mg/kg compared to the others. Also, upregulations in CAT were found with CoQ10 at levels of 5 or 10 mg/kg compared to their counterparts in the other groups. In conclusion, dietary CoQ10 at 5 or 10 mg/kg improves the performance and well-being of European seabass.
