酵母硒对美洲鳗鲡幼鳗生长性能、肌肉品质及抗氧化能力的影响OA

Selenium is an indispensable nutrient for animal growth;it participates in various physiological functions,such as antioxidant and immune responses and metabolism.Sufficient Se levels are crucial for enhancing immunity and regulating immune responses.Supplementation with appropriate doses of Se plays a critical role in improving fish product quality and promotes Se enrichment in fish tissues,thereby creating functional Se-enriched fish.To explore the effects of dietary yeast Se and Se levels on growth performance,body composition,tissue Se content,and antioxidant indexes of American eel(Anguilla rostrata),0;0.2;0.4;and 0.6 mg/kg of yeast Se were added to the basic diet.Juvenile A.rostrata with an initial body weight of 81.60±6.33 g were fed these diets for a 70-day culture period.The growth index and body composition of juvenile A.rostrata were assessed.Se content was measured in the liver,muscle,intestine,and whole fish,alongside antioxidant enzyme activities in the liver and serum.Correlation analyses were conducted to examine the relationships between Se levels in different tissues and their association with antioxidant indices.The results showed that final body weight,specific growth rate,and weight gain rate were all increased in the experimental groups with different levels of Se supplementation.Viscerosomatic and hepatosomatic indices of the Se-0.4 group were significantly lower than those of the Se-0 group(P<0.05).The addition of yeast Se in the diet had no significant effect on final body length,survival rate,and intestinal ratio of weight.Different Se levels had no significant effect on the moisture or crude protein content of A.rostrata;however,they increased total sugar and ash content.Dietary yeast Se concentration had a significant effect on the biological accumulation of Se concentration in the tissues of juvenile A.rostrata;the deposition ability of yeast Se in A.rostrata tissues was in the order of:liver>intestine>muscle.Different doses of yeast Se had a certain promoting effect on glutathione peroxidase,superoxide dismutase,and catalase activities in the liver,whereas it had a certain inhibitory effect on alkaline phosphatase,aspartate aminotransferase,and alanine aminotransferase activities in serum.Se content in A.rostrata tissues was positively correlated;Se accumulation in each tissue exhibited a synergistic effect.In summary,the three doses of yeast Se improved the growth and development of A.rostrata,enhancing muscle quality and antioxidant performance.Based on the quadratic regression model fitting of SGR,the optimum addition amount of yeast Se in A.rostrata feed was 0.48 mg/kg.Considering the effects on growth performance,antioxidant capacity,and actual production cost,the recommended amount of yeast Se in A.rostrata feed was 0.4 mg/kg.