Tan Beiping

Dietary phosphorus requirement of young abaloneHaliotis discus Hannai Ino

An experiment was performed to determine the dietary phosphorus requirement of the young abalone,Haliotis discus hannai. Five semi-purified diets were formulated to provide a series of graded levels of dietary total phosphorus (0.23%–1.98) from monobasic potassium phosphate (KH2P04). The brown alga,Laminaria japonica, was used as a control diet. Similar size abalone were distributed in a single-pass, flow-through system using a completely randomized design with six treatments and three replicates each treatment. The abalone were hand-fed to satiation with appropriate diets in excess, once daily at 17:00. The feeding trial was run for 120-d. Survival rate and soft-body to shell ratio (SB/S) were constantly maintained regardless of dietary treatment. However, the weight gain rate (WGR), daily increment in shell length (DISL), muscle RNA to DNA ratio (RNA/DNA), carcass levels of lipid and protein, soft-body alkaline phosphatase (SBAKP), and phosphorus concentrations of whole body (WB) and soft body (SB) were significantly (ANOVA, P<0.05) affected by the dietary phosphorus level. The dietary phosphorus requirements of the abalone were evaluated from the WGR, DISL, and RNA/DNA ratio respectively, by using second-order polynomial regression analysis. Based on these criteria, about 1.0%–1.2% total dietary phosphorus, i.e. 0.9%–1.1% dietary available phosphorus is recommended for the maximum growth of the abalone.

Availability of phosphorus from selected inorganic phosphate to juvenile abalone,Haliotis discus hannai ino.

The availability of phosphorus to juvenile abalone,Haliotis discus hannai from primary, secondary and tertiary calcium phosphate, primary sodium or potassium phosphate separately or in combination was determined in a 120-day feeding trial. Seven semi-purified diets were formulated to contain relatively constant dietary phosphorus, ranging from 0.78%–0.82%. The concentrations of dietary phosphorus were presumed to be slightly below the requirement for abalone. A brown alga,Laminaria japonica, was used as a control diet. Abalone juveniles of silimar size (average weight 1.18 g; average shell length 18.74 mm) were distributed in a single-pass, flow-through system using a completely randomized design with eight treatments and three replicates each treatment. The survival ranged from 71.1% to 81.1%, and was not significantly (P>0.05) related to dietary treatment. However, the weight gain rate (41.72%–65.02%), daily increment in shell length (36.87–55.07 μm) and muscle RNA-DNA ratio (3.44–4.69) were significantly (P<0.05) affected by dietary treatment. Soft body alkaline phosphatase activity (10.9–19.8 U/g wet tissue) and carcass levels of lipid (7.71%–9.33%) and protein (46.68%–49.35%) were significantly (P<0.05) responsive to available phosphorus of the diets. Dietary treatment had significant effect (P<0.05) on concentrations of phosphorus in the whole body (WB) and soft body (SB). Apparent digestibility coefficients (45%–97%) of phosphorus were also significantly (P<0.05) different between dietary treatments. The results indicated that among these inorganic compounds, primary calcium, potassium and sodium phosphates separately or in combination could be utilized effectively by juvenile abalone as dietary phosphorus sources (availability ranging from 87%–97%). However, secondary and tertiary calcium phosphates were found to be low in availability, the values being 45% and 77%, repectively.

小肽对凡纳滨对虾幼虾生长、体成分、非特异性免疫力及抗病力的影响

本试验旨在研究小肽对凡纳滨对虾幼虾生长、体成分、非特异性免疫力及抗病力的影响。在基础饲料中分别添加0（对照）、0.5%、1.0%、2.0%、4.0%和6.0%的小肽，共配制6种试验饲料，分别命名为S0、S0.5、S1.0、S2.0、S4.0、S6.0。选取初始体重为（0.19±0.01）g的凡纳滨对虾幼虾，随机分为6组，每组设3个重复，每个重复30尾。饲养试验持续56 d。结果表明：各添加小肽组的增重率（WGR）、特定生长率（SGR）和蛋白质效率（PER）均显著高于对照组（ P P P >0.05）。血清中，酚氧化物酶（PO）活性在S1.0和S2.0组显著高于其他组（ P P P P >0.05）；丙二醛（MDA）含量在S4.0和S6.0组显著低于其他组（ P P P P >0.05）；ACP活性在S0.5和S1.0组较高，但与对照组差异不显著（ P >0.05）；AKP活性在S4.0组显著低于对照组（ P P P P P >0.05）。综上所述，饲料中添加1.0%~2.0%的小肽可促进凡纳滨对虾幼虾的生长，提高其非特异性免疫力及抗病力。