克氏原螯虾饲料亚麻酸与亚油酸的适宜比值

OPTIMAL RATIO OF LINOLENIC ACID TO LINOLEIC ACID IN THE DIET OF PROCAMBARUS CLARKII

  • 摘要: 为探究克氏原螯虾(Procambarus clarkii)饲料亚麻酸与亚油酸的适宜比值(ALA/LA), 分别制备ALA/LA为0.14 (R1)、0.38 (R2)、0.74 (R3)、1.28 (R4)、2.37 (R5) 和4.54 (R6)的6种实验饲料, 选取初始体重为(5.99±0.12) g的克氏原螯虾进行为期8周的摄食生长实验。结果显示, R3组克氏原螯虾增重率、特定生长率和肌肉粗脂肪含量最高, 且饲料系数最低; R2组性腺指数最高; R3组肌肉粗脂肪和Σn-6PUFA含量最高; R6组肌肉粗蛋白含量最高; 血清中谷草转氨酶和谷丙转氨酶活性均在ALA/LA为0.38—0.74时较其他组显著降低; 饲料ALA/LA显著影响了肝脏和肠道消化酶活性; 肝脏过氧化氢酶和超氧化物歧化酶活性分别在R3组和R4组达到最大值; R3组肝胰腺丙二醛含量最低; 肠道绒毛宽度在R3组显著升高; 肝胰腺B细胞数量在R4组较其他组显著升高; ALA/LA为0.38—0.74时显著提高了克氏原螯虾的性腺指数。经折线回归分析, 克氏原螯虾饲料中适宜ALA/LA为0.45—0.46。

     

    Abstract: Aquatic animals are unable to synthesize n-3 and n-6series of polyunsaturated fatty acids (PUFA) de novo, and mainly obtain PUFA from feed to support growth and reproduction. The proportion of essential fatty acids in diet is crucial to meet these dietary fatty acid requirements. To investigate the ratio of linolenic acid to linoleic acid (ALA/LA) in diet of Procambarus clarkii, six experimental diets were formulated with ALA/LA ratios of 0.14 (R1), 0.38 (R2), 0.74 (R3), 1.28 (R4), 2.37 (R5) and 4.54 (R6). P. clarkii with an initial body weight of (5.99±0.12) g were selected for an 8-week feeding and growth experiment. The results showed that the weight gain rate, specific growth rate, and muscle crude fat content were the highest in the R3 group, which also had the lowest feed coefficient. The gonad index was the highest in the R2 group. The R3 group exhibited the highest muscle crude fat and Σn-6 PUFA content, while the R6 group exhibited the highest muscle protein content. The serum glutamic oxalacetic transaminase and glutamic pyruvic transaminase activities were significantly lower in groups with an ALA/LA ratio between 0.38 and 0.74. The dietary ALA/LA ratio significantly affected hepatopancreas and intestinal digestive enzyme activities. The activities of catalase and superoxide dismutase in hepatopancreas reached the maximum in the R3 and R4 groups, respectively. The R3 group had the lowest malondialdehyde content in the hepatopancreas. Additionally, intestinal villus width was significantly increased in the R3 group, and the number of hepatopancreas B cells was significantly higher in the R4 group than that in the other groups. The gonadal index of P. clarkii was significantly increased with an ALA/LA ratio between 0.38 and 0.74. The broken-line regression analysis indicated that the optimal dietary ALA/LA ratio for P. clarkii was between 0.45 and 0.46.

     

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