Department of Wildlife and Fisheries Sciences, Texas A&M University System, College Station, TX, 77843-2258, United States; Current address: Department of Aquaculture, Faculty of Agriculture, Universiti Putra, Malaysia, 43400, Serdang, Selangor, Malaysia.
Department of Wildlife and Fisheries Sciences, Texas A&M University System, College Station, TX, 77843-2258, United States.
Fish Shellfish Immunol. 2020 Mar;98:868-874. doi: 10.1016/j.fsi.2019.11.046. Epub 2019 Nov 18.
Fishmeal is being increasingly replaced in aquatic animal diets with alternative plant protein feedstuffs such as soybean meal which have lower concentrations of nucleotides; therefore, supplemental sources of exogenous nucleotides in diets could become increasingly important. A 9-week feeding trial was conducted with triplicate groups of juvenile hybrid striped bass (average initial body weight ± standard deviation, 5.6 ± 0.1 g) to determine the effects of supplementing single purified nucleotides on the growth performance and immune parameters. The basal diet, which utilized menhaden fishmeal (25%) and soybean meal (75%) as protein sources, contained 44% protein, 10% lipid and an estimated digestible energy level of 3.5 kcal g. Single additions of 5'- adenosine monophosphate (AMP), 5'- uridine monophosphate (UMP), 5'- cytidine monophosphate (CMP), 5'- guanosine monophosphate (GMP), and 5'- inosine monophosphate (IMP) disodium salts (Chem-Impex International, Wood Dale, Illinois, USA) were evaluated with each nucleotide added to the basal diet at 0.5% of dry weight at the expense of cellulose. A positive control diet in this trial was a diet containing 5'- AMP from Sigma-Aldrich also supplemented at 0.5% by weight. Results showed significantly (P < 0.05) improved weight gain between fish fed AMP-supplemented diets and the basal diet. No statistical significance (P > 0.05) was detected in whole-body proximate composition and protein retention of fish fed any of the dietary treatments. The respiratory burst of whole blood phagocytes also was significantly (P < 0.05) higher in fish fed the AMP Sigma diet compared to the other dietary treatments. Dietary IMP and AMP both significantly (P < 0.05) enhanced the capacity of isolated phagocytes to generate extracellular superoxide anion compared to all other dietary treatments. No significant differences were seen in other innate immune parameters such as plasma lysozyme, total plasma protein, and total immunoglobulin. The ability of isolated B lymphocytes to proliferate prompted by the presence of lipopolysaccharides was significantly (P < 0.05) different among dietary treatments with the highest simulation index observed in fish fed the diets containing AMP Sigma and UMP; however, it was not significantly different from that of fish fed the basal diet. Based on all the measured responses, it is concluded that AMP at 0.5% of diet had the most positive influence on growth performance and innate immunostimulation of hybrid striped bass.
鱼粉正逐渐被替代，水生动物饲料中的替代植物蛋白饲料，如豆粕，其核苷酸浓度较低;因此，日粮中补充外源核苷酸的来源可能变得越来越重要。本试验采用三重复幼龄杂交条纹鲈(平均初始体重±标准差，5.6±0.1 g)进行了 9 周的饲养试验，以确定补充单一纯化核苷酸对生长性能和免疫参数的影响。基础日粮以鲱鱼粉(25%)和豆粕(75%)为蛋白质来源，含有 44%的蛋白质、10%的脂肪和估计的消化能水平为 3.5 kcal/g。用 5'-单磷酸腺苷(AMP)、5'-尿苷单磷酸(UMP)、5'-胞苷单磷酸(CMP)、5'-鸟苷单磷酸(GMP)和 5'-肌苷单磷酸(IMP)二钠盐(Chem-Impex International，Wood Dale，Illinois，USA)进行了单添加评估，将每种核苷酸以干重的 0.5%添加到基础日粮中，以纤维素为代价。在本试验中，阳性对照饲料是一种含有 Sigma-Aldrich 5'-AMP 的饲料，也以 0.5%的重量补充。结果表明，添加 AMP 的饲料组鱼的体重增长显著(P<0.05)高于基础饲料组。在接受任何日粮处理的鱼的全鱼体成分和蛋白质保留方面均未检测到统计学意义上的差异(P>0.05)。与其他日粮处理相比，添加 AMP 的 Sigma 日粮组鱼的全血吞噬细胞呼吸爆发显著升高(P<0.05)。日粮 IMP 和 AMP 均显著提高了(P<0.05)与其他日粮处理相比，分离吞噬细胞产生细胞外超氧阴离子的能力。在其他先天免疫参数如血浆溶菌酶、总血浆蛋白和总免疫球蛋白方面未观察到显著差异。在存在脂多糖的情况下，分离的 B 淋巴细胞增殖的能力在日粮处理之间有显著差异(P<0.05)，在添加 AMP Sigma 和 UMP 的日粮中观察到的模拟指数最高;然而，与添加基础日粮的鱼相比，这并没有显著差异。基于所有测量的反应，可以得出结论，日粮中添加 0.5%的 AMP 对杂交条纹鲈的生长性能和先天免疫刺激有最积极的影响。
