禁食对养殖大黄鱼体成分、肌肉脂肪酸组成和血清生化指标的影响

Effect of fasting on body composition,muscle fatty acid profiles and serum biochemical parameters of large yellow croaker(Larimichthys crocea)

为了探讨禁食对大黄鱼体成分、肌肉脂肪酸组成和血清生化指标的影响,从海上网箱选择规格相近、健康的养殖大黄鱼105尾[平均体质量(249.07±7.28)g]进行禁食实验,分别在实验开始时及禁食后第3、7、14、21、28、35、42和49天采集实验鱼肌肉和血液样品,进行肌肉营养成分和血清生化指标的测定。结果发现,随着禁食时间的延长,大黄鱼肌肉中水分和粗灰分含量呈现升高的趋势,粗脂肪含量呈现下降的趋势,粗蛋白含量在禁食后第21天下降后基本保持稳定;肌肉中饱和脂肪酸(SFA)和单不饱和脂肪酸(MUFA)含量均无显著变化,多不饱和脂肪酸(PUFA)和n-3系列高度不饱和脂肪酸(n-3HUFA)总量呈现下降的趋势。禁食后第3天血清中的谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)、葡萄糖(GLU)、钾离子(K^+)、钙离子(Ca^(2+))、钠离子(Na^(+)))和氯离子(Cl^-)含量显著上升;甘油三酯(TG)、总胆固醇(CHOL)含量显著下降;血清总蛋白(TP)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)和碱性磷酸酶(ALP)无显著变化。研究表明,随着禁食时间的延长,血清中除了Na^+和Cl^-含量出现波动性上升外,血清中的葡萄糖、蛋白质、脂类、K^+和Ca^(2+)含量以及血清代谢酶活性均出现波动式下降,表明大黄鱼禁食期间主要以脂类作为能量来源,体内营养物质代谢活动强度呈波浪形的起伏变化,随着禁食时间的延长机体代谢活动趋于减弱,但免疫功能和代谢机能未受到明显影响。

This study was conducted to determine the effect of fasting on body composition,muscle fatty acid profiles and biochemical parameters of serum in large yellow croaker（Larimichthys crocea）.105 net-cage cultured healthy fish with similar body weight（249.07±7.28 g） were selected for fasting experiment.The muscle and blood were sampled from experimental fish after 0,3,7,14,21,28,35,42,49 days of fasting for chemical analysis,respectively.The results showed that moisture and crude ash of muscle increased and crude fat decreased during fasting period.The protein content of muscle significantly decreased at 21 days of fasting and then remained constant.Saturated fatty acid（SFA） and monounsaturated fatty acid（MUFA） content in muscle showed no significant change（P〈0.05）,while the total polyunsaturated fatty acid（PUFA） and n-3 high unsaturated fatty acid（n-3HUFA） content significantly decreased at the end of experiment.The activities of serum alanine transaminase（ALT）,glutamic-oxaloacetic transaminase（AST）,lactate dehydrogenase（LDH） and the contents of serum glucose（GLU）,Kalium（K＋）,sodium（Na＋）,calcium（Ca（2＋）） and chloride（Cl-） significantly increased,while serum triglyceride（TG）,Cholesterol（CHOL） contents significantly reduced after 3 days of fasting.Nevertheless serum total protein（TP）,high density lipoprotein cholesterol（HDL-C）,low density lipoprotein cholesterol（LDL-C）contents and alkaline phosphatase（ALP） activity keep relatively stable（P〈0.05）.The content of GLU,protein,lipid and metabolic enzymes activities in serum fluctuated decrease with prolongation of fasting,while Na＋ and Cl-content fluctuated increase.The results suggested that large yellow croaker main used body lipid as energy source during fasting period.The nutrient metabolism intensity showed wave-like fluctuated and turn weak as fasting time going by.But the immunity and metabolism function of large yellow croaker were not significantly harmed by long time fasting.