Dietary nucleotides enhance growth performance,feed efficiency and intestinal functional topography in European Seabass (Dicentrarchus labrax)

Nucleotides, nucleosides and nucleic acids (NU) have many critical functions in supporting life and increasing evidence suggests that exogenous supply can benefit the health of mammals and fish. For these reasons, a 6‐week feeding trial was conducted on juvenile European seabass (Dicentrarchus labrax) with diets containing 0%, 0.15% and 0.3% inclusion of a NU mixture (Laltide^®) derived from the yeast Saccharomyces cerevisiae. At the end of the study no significant differences were found in fish performance, although a tendency towards better performance was indicated in fish fed the Nu0.3 diet. In relation to histological assessment, a significantly greater perimeter ratio; internal to outer (IP/OP) was observed in the posterior intestine of fish fed supplemental NU. Microvilli heights in the posterior intestine were also shown to be significantly promoted in fish fed NU diets (p < 0.05). Goblet cell abundance was shown to be unaffected by the inclusion of NU in the diet (p > 0.05). Overall, this study indicates that orally administered NU may be effective promoters of gut functional topography with marginal associated improvements to fish performance. Nonetheless, longer exposure and/or commercial scale application, and in diets that were challenging in use of high inclusion levels of plant by‐products would potentially amplify improvements in production characteristics, in turn benefiting fish culturists.     

高原线虫草子座和菌核活性成分比较

采用高效液相色谱法(high performance liquid chromatography,HPLC)和紫外分光光度法(ultraviolet-visible spectrophotometry,UV)对高原线虫草(Ophiocordyceps highlandensis)子座和菌核的核苷类、麦角甾醇、总多糖、甘露醇、黄酮、皂苷和三萜等活性成分进行测定和分析。结果表明,核苷类成分、麦角甾醇含量,子座高于菌核;而总多糖、甘露醇、黄酮、皂苷、三萜的含量,菌核高于子座。     

日粮核苷酸对动物免疫功能的影响研究进展

核苷酸（嘌呤和嘧啶）是组成DNA和RNA单体，在体内具有重要的生理生化作用。人和动物能从头合成核苷酸。在机体迅速生长、或动物受到免疫挑战时，一些器官、组织内源合成的不能满足机体的需要。补充日粮核苷酸对于动物免疫细胞、器官的发育及维持免疫系统正常功能有积极作用。     

梅花鹿尾和马鹿尾中4种核苷类成分的高效液相色谱分析

利用高效液相色谱(HPLC)法,首次测定比较了梅花鹿尾和马鹿尾药材中的尿嘧啶、次黄嘌呤、尿苷和黄嘌呤4种核苷类成分的含量.色谱条件:分离柱为SunfireTM C18(250mm×4.6mm,5μm),流动相为乙腈-水,梯度洗脱,流速1 mL/min,检测波长260 nm,柱温30℃.结果表明:4种核苷类组分含量在2种...     

基于牛蒡根的灵芝固体发酵菌质化学成分的初步分析

以牛蒡根为发酵基质,初步探究灵芝固体发酵所获菌质中多种化学成分的变化。利用可见分光光度计、高效液相色谱仪及定氮仪等测定了牛蒡根原药材和牛蒡根灵芝菌质中多糖、总三萜酸、总黄酮、核苷及蛋白质含量,并进行HPLC指纹图谱分析。牛蒡根经灵芝菌丝体发酵后,多糖含量由9.94%降低至2.76%,总三萜酸含量从无升高至0.14 mg·g^-1,总黄酮含量由3.47%降低至0.34%,4种核苷总量由861.05μg·g^-1升高到1 113.49μg·g^-1,且新合成了腺苷,蛋白质含量由13.38%升高至17.28%。HPLC指纹图谱显示牛蒡根在灵芝发酵前后化学成分差异较大。灵芝固体发酵使牛蒡根多糖和黄酮含量降低,核苷和蛋白质含量升高,并新产生三萜酸和腺苷,具有明显的生物转化作用。     

18个龙眼品种果肉中核苷物质的HPLC定量测定

采用HPLC法同时分离测定了龙眼肉中的为尿嘧啶、胞苷、尿苷、胸腺嘧啶、肌苷、鸟苷、胸苷、腺嘌呤、腺苷等多种核苷成分,并用外标法计算各种核苷的含量。结果发现,鸟苷、尿苷、腺苷含量较高,多数龙眼品种为30～70μg/g;胸腺嘧啶、胞苷含量次之,普遍在10～30μg/g之间;胸苷、尿嘧啶含量较低,普遍在3～10μg/g之间;龙眼肉中还含有少量的腺嘌呤和次黄嘌呤核苷。如果以鸟苷、次黄嘌呤核苷、腺苷等核苷含量的多少来衡量龙眼品种的优劣,则石硖、双孖木、古山二号、储良、大乌圆、东壁、福眼等为较优的龙眼品种。     

Effect of purine nucleosides on growth performance,gut morphology,digestive enzymes,serum profile and immune response in broiler chickens

1. This study was conducted to evaluate the effects of purine nucleosides on performance, gut morphology, intestinal enzymes and immunity functions in broiler chickens from 0 to 21 d of age.

2. A total of 360 1-d-old male chickens (Cobb 500) were randomly assigned to 4 treatments with 6 replications. Experimental diets consisted of a control without any additives and diets containing 0.1% pure adenosine, 0.1% pure guanosine and 0.1% equal aliquots of pure adenosine and guanosine. Two birds per cage (12 birds per treatment) were killed on d 11 and 21 in order to obtain serum samples for lipid profile, jejunal samples for morphology and mucosal immunity, digestive enzymes for epithelial maturation, and bursa and spleen samples for relative weight of immune organs to live body weight.

3. Birds receiving adenosine in their diets showed a significant increase in body weight and average daily gain and a significantly lower feed conversion ratio compared to the control birds. Villus height and width in jejunal samples also increased significantly in birds supplemented with adenosine. Although maltase was not affected by the experimental diets, adenosine increased alkaline phosphatase and aminopeptidase. Adenosine and its combination with guanosine boosted mucosal immunity as a result of increased IgA production. While there was no significant difference among treatments regarding the relative weight of the spleen, adenosine increased the relative weight of the bursa of Fabricius. Present results also showed that adding guanosine to broiler diets had no significant effects on growth, gut morphology, enzymes activity and immunological indices.

4. In conclusion, the improvement in growth performance, gut morphology and immunity in birds receiving adenosine demonstrated that pure adenosine could be a beneficial feed additive for the poultry industry, while guanosine showed no significant improvement.