微藻粉替代鱼油对星斑川鲽幼鱼生长、体组成和生理指标的影响

为探讨微藻粉替代鱼油对星斑川鲽(Platichthys stellatus,Pallas 1788)幼鱼生长、体组成和生理指标的影响,以鱼油为主要脂肪源配制基础饲料(FO),分别用裂壶藻粉(SO)、微绿球藻粉(NO)及两种藻粉的混合物(MO)替代鱼油中的DHA、EPA,不足部分用玉米油补齐,制成4种等氮等能的实验饲料,投喂星斑川鲽幼鱼(初始体重7.35 g±0.03 g)90 d。结果显示,与FO组相比,SO组的生长性能无显著差异(P0.05),NO组和MO组特定生长率、蛋白质效率和脏体比显著降低(P0.05),饲料系数显著增大(P0.05);MO组的全鱼粗蛋白含量显著高于其他组(P0.05),FO组与MO组的全鱼粗脂肪含量显著高于其他组(P0.05),FO组背肌粗灰分含量显著低于其他组(P0.05);藻粉替代鱼油对肌肉和肝脏脂肪酸组分影响显著,肌肉的C16:0和DHA含量与其在饲料中所占的百分比呈显著正相关(r=0.973,0.967,P0.05),C14:0和C16:1n-7呈极显著正相关(r=1.00,0.996,P0.01),肝的C18:2n-6、n-6 PUFA和DHA/EPA呈显著正相关(r=0.983,0.976,0.977,P0.05),C16:1n-7呈现极显著正相关(r=0.992,P0.01);NO组和MO组血清谷丙转氨酶(ALT)、甘油三酯(TG)、胆固醇(CHO)和碱性磷酸酶(ALP)的含量较FO组显著降低(P0.05),NO组血清谷草转氨酶(AST)和葡萄糖(GLU)含量显著低于其他组(P0.05)。研究表明,本实验条件下裂壶藻粉可以替代星斑川鲽幼鱼饲料中的鱼油而不对其生长和生理指标产生负面影响,并且在一定程度上能提高星斑川鲽的营养价值。

Effects of replacing fish oil with microalgae meals on growth performance, tissue proximate composition, and biochemical indices in juvenile starry fiounder, Platichthys stellatus

A 90-day feeding trial was conducted to investigate the effects of fish oil substitution with microalgae meals on growth performance, tissue proximate composition, and biochemical indices in juvenile starry flounder, Platichthys stellatus (initial body weight 7.35 g±0.03 g). Four groups of isonitrogenous and isolipidic diets were formulated using different primary lipid sources: fish oil (FO), Schizochytrium meal (SO), Nannochloropsis meal (NO), and the mixture of these two algae meals (MO), with the remaining part filled with corn oil. Results showed that growth performance was not significantly different between FO and SO, whereas specific growth rate (SGR), protein efficiency ratio (PER), and viscerosomatic index (VSI) of NO and MO were significantly lower than FO (P<0.05). Feed efficiency (FE) of MO and NO was the opposite. The body crude protein content of MO was sig-nificantly higher than that in the other groups (P<0.05), while body crude lipid content of FO and MO were sig-nificantly higher than that in the other groups (P<0.05). The muscle ash content of FO was significantly lower than that in the other groups (P<0.05). Fatty acid composition of muscle and liver were directly influenced by dietary fatty acid composition (P<0.05). The percentages of C16:0 and DHA in muscle were positively correlated with that of the diets (r=0.973 and 0.967, respectively, P<0.05), and the percentages of C14:0 and C16:1n-7 were significantly positively correlated with that of the diets (r=1.00 and 0.996, respectively, P<0.01). The percentages of C18:2n-6, n-6 PUFA, and DHA:EPA in liver were also positively correlated with that of the diets (r=0.983, 0.976, and 0.977, respectively, P<0.05), while C16:1n-7 showed a significantly positive correlation (r=0.992, P<0.01). Compared with FO, levels of serum alanine aminotransferase (ALT), triglyceride (TG), cholesterol (CHO), and alkaline phos-phatase (ALP) of NO and MO were significantly decreased (P<0.05). Additionally, levels of serum aspartate ami-notransferase (AST) and glucose (GLU) of NO were significantly lower than those in other groups (P < 0.05). In summary, there were no negative effects on growth and physiology when fish oil was replaced with Schizochy-trium meal, and this can improve the nutritional value of P. stellatus to a certain extent.