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探讨了在室外低盐度池塘网箱中饲料中w(蛋白)对凡纳对虾Litopenaeus vannamei幼虾生长表现和免疫状况的影响。设计6组等能饲料,其w(蛋白)为20%,25%,30%,35%,40%,45%;初始体质量为0·28g左右的凡纳对虾幼虾放养在悬挂于池塘中的18个小网箱中(1m×1m×1·2m),每个处理设置3个网箱,每箱放养100尾幼虾,池塘水的盐度约为10-3,虾自由摄食,饲养期为6周。结果表明,存活率没有显著差异。凡纳对虾的摄食量、特殊生长率和饲料效率在饲料w(蛋白)从20%增长到40%时随w(蛋白)增加而显著增加,蛋白质效率和氮保留效率则饲料w(蛋白)最低(20%)和最高(45%)的组显著低。全虾和肌肉粗蛋白含量随饲料w(蛋白)增加而显著增加。肝胰脏糖原和肝脂肪含量在饲料w(蛋白)从20%升至35%时随饲料w(蛋白)增加而显著降低,在饲料w(蛋白)高于35%的组中随饲料w(蛋白)加而显著升高,而肌糖原在饲料w(蛋白)从20%增至30%时显著降低,在饲料w(蛋白)高于30%的组间无显著差异。肌脂肪在各组间无显著差异。血淋巴细胞总数、血淋巴蛋白和血蓝蛋白含量、酚氧化酶活性、盐度应激测试存活率只有饲料w(蛋白)为20%的组显著低于其它各组,在饲料w(蛋白)高于20%的组之间无显著差异。从本试验表明,在低盐度室外池塘中,凡纳对虾幼虾在自由摄食条件下,生长表现对饲料w(蛋白)的反应表明其适宜饲料w(蛋白)在40%,饲料w(蛋白)低于30%导致w(肝糖原)和w(肝脂肪)显著增高,饲料w(蛋白)低于20%导致免疫状况降低。
The effects of dietary w (protein) in diet on juvenile shrimp Litopenaeus vannamei juvenile shrimp growth performance and immune status were studied in outdoor low-salinity pond cages. Six groups of feedstuffs were designed and their w (protein) was 20%, 25%, 30%, 35%, 40% and 45%. The juvenile shrimp with initial body mass of 0.28g was stocked in ponds In the 18 small cages (1m × 1m × 1 · 2m), each treatment set up three cages, stocking 100 shrimp per box, pond water salinity of about 10-3, shrimp free feeding, Feeding period is 6 weeks. The results showed no significant difference in survival. Food intake, special growth rate, and feed efficiency of L. vannamei increased significantly with w (protein) increase from 20% to 40% of feed w (protein), whereas protein w and nitrogen retention gave the lowest feed w (20%) and the highest (45%) were significantly lower. Whole shrimp and muscle crude protein content increased significantly with feed w (protein). Hepatic pancreatic glycogen and hepatic fat content were significantly reduced with increasing dietary w (protein) from 20% to 35% of feed w (protein), with diet w (protein) above 35% (Protein) increased significantly, whereas muscle glycogen decreased significantly from 20% to 30% of dietary w (protein) and no significant difference between the groups with feed w (protein) above 30%. There was no significant difference in muscle fat between groups. The total number of blood lymphocytes, haemolymph and hemocyanin, phenoloxidase activity, salinity stress test survival rate was significantly lower in feed w (protein) 20% group than in other groups, There was no significant difference between the groups above 20%. The results of this experiment showed that the response of growth performance to feed w (protein) in juvenile Litopenaeus vannamei in low salinity outdoor ponds showed that the optimum feed w (protein) was 40%, feed w (protein ) Below 30% results in a significant increase of w (hepatic glycogen) and w (hepatic fat) and below 20% of feed w (protein) leads to a decrease in immune status.