异育银鲫幼鱼对饲料中维生素K需求的研究

以不同维生素K水平(0.13、2.15、3.25、6.40、12、17.20和23.20 mg/kg饲料)的7种精制饲料喂养初始体重约为(2.17±0.01) g的异育银鲫(Carassius auratus gibelio)10周, 每个处理3个重复, 研究异育银鲫对维生素K的需求量。结果显示: 饲料中维生素K的添加可以明显降低摄食率, 饲料中维生素K含量为2.15 mg/kg时, 摄食率出现最大值, 之后显著下降(P<0.05), 在12 mg/kg时达到最低值。特定生长率随着维生素K的添加表现出升高的趋势, 饲料中维生素K含量为12 mg/kg时, 出现最大值, 但是差异不显著(P>0.05)。饲料中维生素K的含量从0.13 mg/kg升至3.25 mg/kg时, 饲料效率显著升高(P<0.05), 随着饲料中维生素K的进一步添加, 趋于稳定(P>0.05), 在12 mg/kg时达到最大值, 并且与特定生长率呈正相关关系(SGR=0.01 FE+0.95, R²=0.95)。血液红细胞数目随着饲料维生素K含量的增加先显著升高(P<0.05), 在6.40 mg/kg时达到最大值, 之后趋于稳定(P>0.05)。血红蛋白含量、血球容积比、血清钙含量与血液中红细胞数目表现出相似的趋势, 均在不添加维生素K组出现最低值, 但是差异不显著(P>0.05)。肝体比、肥满度及鱼体生化组成均不受饲料维生素K水平的影响(P>0.05)。分别对饲料效率、红细胞数目进行折线回归得出异育银鲫幼鱼对维生素K的最适需求量为3.73—6.72 mg/kg饲料。

DIETARY VITAMIN K REQUIREMENT OF JUVENILE GIBEL CARP (CARASSIUS AURATUS GIBELIO)

A 10-week feeding experiment was conducted to determine vitamin K requirement of juvenile gibel carp (Carassius auratus gibelio). Purified diets with seven levels (0.13, 2.15, 3.25, 6.40, 12, 17.20 and 23.20 mg/kg diet) of supplemental vitamin K₃ (menadione sodium bisulfite, MSB) were fed to C. gibelio (mean weight 2.17±0.01 g). Each diet was fed to triplicate groups of fish. The results showed that fish fed with the diet supplemented with 2.15 mg vitamin K/kg had significantly higher feeding rate (FR) than fish fed with diets supplemented with 12 mg vitamin K/kg (P<0.05). Specific growth rate (SGR) increased with increasing dietary vitamin K levels and reached the highest value when dietary vitamin K content was 12 mg/kg (P>0.05). Feed efficiency (FE) was the highest in fish fed with diet supplemented with ≥3.25 mg vitamin K/kg, intermediate with 2.15 mg vitamin K/kg supplemented diet and the lowest in the control group (P<0.05). FE reached the highest value when the dietary vitamin K content was 12 mg/kg (P<0.05) and showed a linear correlation with SGR (SGR=0.01 FE+0.95, R²=0.95). The number of red corpuscles (RBC) in blood increased significantly with increasing dietary vitamin K level (P<0.05) and reached the plateau at 6.40 mg vitamin K/kg. The Hb content, Hct and serum Ca content followed the same trend as RBC and were the lowest in gibel carp fed with diet without vitamin K supplementation (P>0.05). HSI, CF and whole body composition were not affected by dietary vitamin K level (P>0.05). Based on the broken-line regression between FE or RBC and dietary vitamin K level, we concluded that the adequate supplemental dietary vitamin K content for gibel carp was 3.73—6.72 mg/kg.