维生素A对吉富罗非鱼生长、血清生化指标和肌肉品质的影响

Effect of dietary vitamin A on growth performance,serum biochemical indices and meat quality of GIFT,Oreochromis niloticus

【目的】研究饲料中维生素A不同水平对吉富罗非鱼生长性能、血清生化指标和肌肉品质的影响,并确定体质量约为78g/尾左右的吉富罗非鱼对饲料中最适宜的维生素A需要量。【方法】选用初始体质量为(78.09±1.47)g/尾的吉富罗非鱼(Oreochromis niloticus)315尾,随机分成7组,每组3个重复,每重复15尾鱼,分别饲喂维生素A水平为0(对照组),750,1 500,3 000,6 000,12 000,24 000IU/kg的7组饲料(粗蛋白、粗脂肪含量分别为31.00%和7.90%),饲养12周后测定吉富罗非鱼的生长指标、血清生化指标,并对其肌肉品质进行评价。【结果】试验鱼的增重率、特定生长率和饲料效率随着饲料维生素A的提高而显著增加(P<0.05)。随着饲料中维生素A添加水平的增加,吉富罗非鱼血清中谷丙转氨酶和谷草转氨酶活性均先降低后升高,对照组吉富罗非鱼血清谷丙转氨酶和谷草转氨酶活性显著高于维生素A添加组(P<0.05);血清中碱性磷酸酶活性先增大后趋于稳定,其中3 000,6 000,12 000和24 000IU/kg维生素A组碱性磷酸酶活性显著高于0,750IU/kg维生素A组(P<0.05)。不同处理组的全鱼粗脂肪、粗蛋白、粗灰分和水分含量无显著性差异(P>0.05),但随着饲料中维生素A水平的升高,鱼体粗脂肪和粗蛋白含量均呈升高趋势。各处理组吉富罗非鱼的肌肉硬度、凝聚性、弹性、黏性、咀嚼性和回复性均无显著性差异(P>0.05)。【结论】在本试验条件下,饲料中添加维生素A对肌肉品质的影响不显著,但可有效促进吉富罗非鱼的生长,降低血清转氨酶的活性。对罗非鱼增重率和饲料中维生素A含量进行折线回归分析,可知吉富罗非鱼对维生素A的适宜需要量为2 954.84IU/kg。

【Objective】The purpose of this study was to detect the effect of different vitamin A levels on growth,feed utilization,body composition some serum biochemical indices and meat quality,and to determine the suitable requirement of vitamin A of GIFT at the body weight of 78 g.【Method】A total of 315 fish with an average initial weight of(78.09±1.47)g were divided in 7 groups and fed on diets supplemented with 0(basal diet),750,1500,3000,6000,12000,and 24000 IU/kg vitamin A.Each diet had three replicate groups with 15 each for 12 weeks.Growth performance,partial serum biochemical indicators and the meat quality of GIFT were detected and analyzed.【Result】With the increase of dietary vitamin A,the weight gain rate,feed efficiency and special weight gain rate were significantly improved(P<0.05).The serum aspertate aminotransferase and alanine transaminase were firstly decreased and then increased as the levels of dietary vitamin A increased,and aspertate aminotransferase and alanine transaminase in the control group were significantly higher than those in the vitamin A groups(P<0.05).The serum alkaline phosphatase was firstly increased and then remained unchanged as the dietary vitamin A increased.The activities of alkaline phosphatase in the 3000,6000,12000 and 24000 IU/kg groups were significantly higher than other groups(P<0.05).No significant differences existed in crude lipid,crude protein,ash and moisture of fish(P>0.05),but the crude lipid and crude protein contents showed an upward trend with the increase of dietary vitamin A.There were no significant differences in muscle hardness,cohesiveness,springiness,gumminess,chewiness and resilience in each group(P>0.05).【Conclusion】The addition of vitamin A had no significant effects on meat quality,but it promoted the growth of fish and decreased serum aminotransferase activities.Based on the relationships between weight gain rate and dietary vitamin A level,the proper dietary vitamin A level for GIFT was 2954.84 IU/kg diet.