摘要:以CoCl2·6H2O為鈷(Co)源,配制成Co含量為0.15、0.23、0.44、0.85、1.68、2.67、4.33 mg/kg的7組精制飼料,喂養(yǎng)尼羅羅非魚(Oreochromis niloticus)幼魚,研究飼料中的Co含量對其生長性能、飼料利用、全魚體成分、血液指標及肝臟Co含量的影響,以確定尼羅羅非魚幼魚飼料中Co的需要量。結(jié)果發(fā)現(xiàn),飼料中的Co對尼羅羅非魚幼魚的平均末重、增重率、特定生長率、飼料效率、蛋白質(zhì)效率均無顯著影響(P﹥0.05);對尼羅羅非魚幼魚的體成分無顯著影響(P﹥0.05);對血液指標和肝臟Co含量的影響顯著(P﹤0.05),血紅蛋白質(zhì)量濃度、紅細胞計數(shù)、肝臟Co含量隨著飼料中Co含量的增加而增加。對紅細胞計數(shù)的折線回歸分析得出,飼料中Co的需要量為0.29 mg/kg;對肝臟Co含量的折線分析得出,飼料中Co的需要量為3.08 mg/kg。因此,尼羅羅非魚幼魚飼料中Co的需要量為0.30~3.00 mg/kg。
關(guān)鍵詞:尼羅羅非魚(Oreochromis niloticus);鈷;生長性能;飼料利用;血液指標;全魚體成分
中圖分類號:S965.125;S963.73+4 文獻標識碼:A 文章編號:0439-8114(2011)19-4021-05
Dietary Cobalt Requirements of Juvenile Tilapia,Oreochromis niloticus
LIU Wei,WEN Hua,JIANG Ming,WU Fan,TIAN Juan
(Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences / Key Laboratory of Freshwater Biodiversity Conservation and Utilization, Ministry of Agriculture, Wuhan 430223,China)
Abstract: To determine the Co requirement for juvenile tilapia (Oreochromis niloticus), experiments had been performed to investigate the effects of Co concentration to growth, feed efficiency, hematology indices, liver Co accumulation and whole body composition of fish. Using the CoCl2·6H2O as Co source, a total of seven sets purified diets with 0.15,0.23,0.44,0.85,1.68,2.67 and 4.33 mg/kg Co were used in this study respectively. The results showed that there were no significant effects on the mean final weight, weight gain, special growth rate, feed efficiency, protein efficiency rate and whole body composition of the juvenile tilapia(P>0.05), while the effects on the hematology indices and liver Co accumulation were significant(P<0.05). Hemoglobin concentrations, red blood cells and liver Co concentrations were increased as the Co concentration increased. The regression analysis for red blood cells and liver Co accumulation indicated the Co requirements were0.29 mg/kg and 3.08 mg/kg respectively. Therefore, the suitable Co concentration in the diet was 0.30~3.00 mg/kg.
Key words: Oreochromis niloticus; cobalt; growth; feed efficiency; hematology indices; whole body composition
鈷(Co)作為動物必需的礦物元素之一,是維生素B12的構(gòu)成成分[1],飼料中添加Co可以增加動物組織中維生素B12的含量,對維持動物生長起著十分重要的作用[2-6]。Co的功能并不限于參與維生素B12的合成,已經(jīng)證明Co直接參與造血過程[7],還參與機體的氮吸收、血紅蛋白和肌紅蛋白的合成[8]。魚類可以從水體中直接獲取礦物質(zhì),也可以從飼料中攝入;但是,因為水體中鈣的競爭與溶解性有機質(zhì)的絡(luò)合作用,虹鱒(Oncorhynchus mykiss)不能通過鰓吸收Co[9]。
尼羅羅非魚(Oreochromis niloticus)是我國主養(yǎng)魚品種之一,飼料中的Co在其體內(nèi)經(jīng)過微生物的轉(zhuǎn)化成為維生素B12的構(gòu)成成分[10]。Anadu等[11]研究發(fā)現(xiàn)飼料中添加Co可以促進齊氏羅非魚(Tilapia zillii)的生長?!?br>