Capacity for digestive hydrolysis and amino acid absorption in Atlantic salmon (Salmo salar) fed diets with soybean meal or inulin with or without addition of antibiotics

This experiment was done to study the effects of dietary soybean meal (SBM) and inulin (a prebiotic) on the capacity for digestive hydrolysis and amino acid absorption by Atlantic salmon, and how a dietary supplement of the broad-spectrum antibiotic oxytetracycline (OTC) modulated these responses. A control diet (FM) was made from fish meal, fish oil and extruded wheat. Two similar diets were made with 250 g soybean meal (SBM) or 75 g inulin kg^− 1. Each diet was made with or without a supplement of 3 g OTC kg^− 1. All six diets contained yttrium oxide for estimation of apparent nutrient absorption. Each diet was fed to two groups of 172 g salmon kept in 1 m² tanks with 9 °C saltwater for 3 weeks. Intestinal organs were then sampled and weighed. Gastrointestinal tracts (GIT) were sectioned for analyses of brush border alkaline phosphatase (ALP) and leucine aminopeptidase (LAP) activities. Tissue from the distal intestine (DI) was also fixed for histological examination. Digesta from the different sections were freeze dried for estimation of trypsin and amylase activities, and of apparent absorption of amino acids (AA), nitrogen (N), and sulphur (S). About 85% of the trypsin activity, 70% of the amylase activity, 85% of the ALP activity, and 82% of the LAP activity were found in the proximal (PI) and mid (MI) intestine of fish with functional DI, and the absorption of AA, N, and S was quantitatively completed in the MI. Dietary OTC resulted in lower relative liver weight, but apart from increased ALP and LAP activities in DI when feeding OTC in combination with inulin, OTC did not modify the responses to dietary SBM or inulin. Dietary SBM resulted in lower relative liver weight, and induced pathomorphological changes in the DI mucosa, thus lower the ALP and LAP activities in the DI. SBM also stimulated absorption of AA, N, and S in the PI, but at the same time increased the activities of trypsin and amylase in the DI, indicating reduced re-absorption and increased faecal losses of these endogenous enzymes. Dietary inulin did not damage the DI, and stimulated intestinal growth and higher relative mass of the GIT. Inulin without OTC did not affect the hydrolytic and absorptive capacity of the salmon GIT.     

玉米苗期耐碱性QTL定位分析

利用郑58/昌7-2构建的156个玉米F₂：3家系为作图群体,在100 mmol/L Na₂CO₃溶液的碱性胁迫下进行玉米苗期耐碱性鉴定,并利用SSR标记构建的分子遗传连锁图谱进行QTL分析。采用复合区间作图法共检测到4个与玉米苗期耐碱率相关的QTL,分布于第2、5、7条染色体上,单个QTL可解释的表型贡献率范围为1.1%～8.6%。所检测到的4个QTL的增益等位基因均来自于耐碱亲本郑58。     

两种土壤碱解氮测定方法的比较

测量土壤碱解氮含量过去一般使用碱解扩散吸收法,试验研究旨在使用德国GERHARD凯氏定氮蒸馏法测定土壤碱解氮,对凯氏定氮蒸馏法进行了改进,确定了合适的蒸馏时间和蒸馏效率,与传统碱解扩散法相比,测量结果更准确,紧密度更高,操作简便,节省时间,为土壤碱解氮含量测定提供了一种准确、快速、高效的测定方法。     

关于碱性水域水化因子与渔业利用问题的探讨

根据1986～1992年对三勇水库、敖包泡等几个碱性水域的渔业状况及水化学观测的结果,总结了养鱼水域碱度的高限指标。提出碱度16 mmol·L~(-1)(pH9.24)是可进行鲤、草、鲢精养的碱度上限。碱度在18 mmol·L~(-1)(pH9.42)以上的水域要选择耐碱鱼类养殖。鲢鳙在此水域中不能存活。     

卵黄免疫球蛋白配基亲和纯化碱性磷酸酶

 以卵黄免疫球蛋白(immunoglobulin　yolk,IgY)为配基,对小牛肠组织来源的碱性磷酸酶进行免疫亲和纯化。采用1.5mol·L-1的NaCl进行洗脱,可使酶的纯化倍数达到64倍,活力回收率达到90%。IgY抗体对碱性磷酸酶亲和力的测定结果显示固有亲和力和相对亲和力分别为6.275×10-7　mol·L-1和5.0 μg·ml-1。     

北太平洋金枪鱼延绳钓钓钩垂直分布及浸泡时间对渔获物的影响

为积累黄鳍金枪鱼 (Thunnus albacares) 幼鱼陆基循环水养殖基础数据,测定了不同体质量的黄鳍金枪鱼幼鱼血清、肌肉、肝脏、胃、肠道等组织的酸性磷酸酶 (ACP)、碱性磷酸酶 (AKP)、淀粉酶、脂肪酶、蛋白酶等活性。结果显示,ACP活性在各组织中由高至低为肠道>肌肉>肝脏>血清,AKP活性则为肠道>肝脏>肌肉>血清。随着体质量的增加,ACP活性在肌肉、肠道和肝脏组织中差异较小,而AKP活性在肝脏中呈逐渐上升的趋势,且相邻两组间差异显著 (P<0.05),其在肠道、肌肉中呈波动性变化;黄鳍金枪鱼幼鱼消化酶活性整体稳定,组间差异不显著 (P>0.05),仅在体质量达1 000 g时肠道胰蛋白酶活性显著下降 (P<0.05),随后小范围浮动,组间差异不显著 (P<0.05)。综上,ACP和AKP活性在黄鳍金枪鱼幼鱼组织中较高且稳定,这种稳定的高活性模式可保证机体对磷 (P) 高效分解、吸收、再利用,提供对外源物的持续免疫力;黄鳍金枪鱼在养殖期间营养需求稳定,且蛋白质需求旺盛。     

Breed‐specific variation of hematologic and biochemical analytes in healthy adult Bernese Mountain dogs

Background: Hematology and serum biochemistry reference intervals in dogs may be affected by internal factors, such as breed and age, and external factors, such as the environment, diet, and lifestyle. In humans, it is well established that geographic origin and age may have an impact on reference intervals and, therefore, more specific reference intervals are sought for subpopulations. Objective: The objective of this study was to validate and transfer standard laboratory reference intervals for healthy Bernese Mountain dogs and to create new intervals for analytes where the established laboratory reference intervals were rejected. Methods: The procedure was performed using the human Clinical and Laboratory Standards Institute‐approved model modified for veterinary use. Thirty‐two dogs were included in the study using a direct a priori method, as recommended. Results: While 23 of the standard laboratory reference intervals were readily validated, 7 of the analytes (eosinophils, MCHC, alkaline phosphatase [ALP], γ‐glutamyltransferase, total bilirubin, amylase, and cholesterol) required new reference intervals according to the standard. These were calculated using the robust method. In particular, the new reference range for ALP was wide compared with the established laboratory reference interval. No clinical causes were found for differences in the results of these analytes. Conclusion: We found significant differences in 7 hematologic and serum biochemical analytes for which a breed‐specific variation appears to be the most plausible explanation. Breed‐specific reference intervals for Bernese Mountain dogs will help avoid misinterpretation of laboratory results in the diagnostic process.     

水胺硫磷对鲫鱼碱性磷酸酶活性的影响

以鲫鱼为实验对象,研究水胺硫磷对鲫鱼各组织碱性磷酸酶(ALP)活性的影响。急性毒性测定表明,水胺硫磷对鲫鱼的96h LC50为3.0 mg/L,亚致死浓度的水胺硫磷暴露会导致鲫鱼ALP的活性发生变化。在所受检测的组织中,ALP活性在暴露期间均受到不同程度的影响,但随着水胺硫磷暴露时间延长,碱性磷酶活性均呈明显的下降趋势,提示SDS暴露所引起的酶活性变化与暴露时间有一定的相关性。     

倍花提取物碱法水解制取没食子酸的研究

研究了倍花提取物碱法水解制备没食子酸的工艺条件，重点叙述了水解温度，碱用量及活性炭用量对没食子酸产品收率及颜色指标的影响，并确定了最佳工艺条件。     

初花后土壤碱解氮浓度对棉花生物量和氮素累积特征的影响

试验于2009-2010年分别在江苏省棉花科技示范基地东台市(120°19' E, 32°52' N)和大丰市(120°28' E,33°12' N)进行。设置6个水平(0、150、300、375、450和600 kg hm^–2)施氮量,研究土壤碱解氮浓度变化特征及对棉花生物量和氮素累积特征的影响。结果表明,棉花初花后土壤碱解氮浓度的动态变化可用三次函数方程模拟,棉花生物量、氮素累积动态可用Logistic方程拟合;土壤碱解氮浓度快速下降期的平均速率、持续时间分别与棉株生物量、氮素快速累积期的最大相对累积速率、持续时间有较高的相关性;在375 kg hm^–2施氮量下,土壤碱解氮浓度快速下降期具最佳平均速率和持续时间,棉株生物量和氮素快速累积期有最优的累积特征值,棉花具有最优的生物量、氮素累积特征值,棉花产量最高、综合品质最优。高施氮量和低施氮量皆不利于棉花生物量和氮素的累积。因此,适宜的施氮量及施氮运筹可调节棉花初花后土壤碱解氮浓度的动态变化,优化棉花生物量和氮素的累积以及产量和品质。