大球盖菇漂烫液喷雾干燥制营养精粉工艺优化

为了充分利用大球盖菇漂烫液的营养成分,对其进行喷雾干燥,并优化其工艺参数,选取热风温度、雾化压力和总固形物质量分数3个因素进行响应面法组合设计,对大球盖菇漂烫液喷雾干燥工艺参数进行优化。结果显示:大球盖菇漂烫液喷雾干燥的较佳工艺条件为β-环糊精添加量15%、进料流量10mL/min、进料温度70℃、热风温度172℃、雾化压力92MPa、总固形物质量分数15%,该条件下大球盖菇漂烫液营养精粉得率为60.26%、抗氧化保留率83.92%、含水率3.2%、溶解时间65s。研究为实现大球盖菇漂烫液的资源化利用提供参考。     

浙北地区小龙虾养殖情况的调查与分析

本文主要概述了小龙虾在浙北地区的养殖情况,通过对养殖户的具体调查,总结了当前小龙虾的养殖中存在的养殖误区,同时对养殖过程中应注意的问题进行了深入分析,并提出了相关解决办法。     

海蓬子中高亲和钾离子转运体SbHKT1基因的克隆、表达及生物信息学分析

本研究利用RACE技术从真盐生植物海蓬子中获得了高亲和钾离子转运体SbHKT1基因1647bp完整的ORF框。序列分析结果表明,该基因编码548个氨基酸,分子量为62.10kD,理论等电点为9.33;氨基酸序列中第1个～第35个属信号肽序列,第197个～第537个属离子转运体（TrkH）家族特征序列;该基因编码的蛋白具有10个跨膜结构,N端跨膜区及中部膜上呈现明显的疏水性,C端及中部多个跨膜区呈现强疏水性,符合载体类运输蛋白的特点,因此推测SbHKT1蛋白为跨膜运输蛋白。Blast分析显示该蛋白与碱蓬SsHKT1氨基酸同源性高达77%,与冰叶日中花、赤桉和小麦HKT类蛋白的同源性分别为63%、52%和46%。SbHkt1基因表达存在组织特异性：正常生长条件在根、茎中表达较低,在叶片中几乎看不到表达;在高盐低钾的环境下,各组织表达明显升高,高盐低钾胁迫处理8h,其根部表达处于高峰期;经100μmol/L脱落酸处理4h,根部表达达到最高;干旱胁迫（20%PEG6000）处理2h,根部表达量明显上升。由此推断,该基因参与了植物在高盐低钾、渗透、干旱等非生物胁迫下的生理调控。由于目前已克隆的HKT类蛋白基因多来自非盐生植物,对盐生植物内源HKT基因的研究相对较少,因此,海蓬子内源HKT1基因的全长的获得有助于我们进一步研究该基因在高盐钾饥饿环境下运输钾离子,调节植物体内Na＋/K＋平衡的功能,对于揭示真盐生植物的耐盐机制,将其运用于非盐生植物,培育新的耐盐品种具有一定的意义。     

Effects of increasing tryptophan intake on growth and physiological changes in nursery pigs

Tryptophan (Trp) as a precursor of serotonin (5-hydroxytryptamine, 5-HT) has long been used to extenuate aggressive behavior and control stress of humans as well as several farm animals. This study was conducted to determine the effect of supplemental L-Tryptophan (L-Trp) on growth, cerebral 5-HT concentration, stress hormone concentration, oxidative stress status, and behavior response of pigs under social stress, and also to determine an optimal daily total Trp intake that would benefit nursery pigs under social stress. Seventy two individually housed barrows at 6 wk of age were randomly allotted to 6 treatments with supplementation of 0, 2, 4, 6, 8, or 10 g L-Trp/kg to corn and soybean meal-based feedstuffs. Pigs were fed assigned feedstuffs for 15 d. Body weight was measured on d 0, 5, 10, and 15. Saliva and blood were collected on d 5, 10, and 15. On d 5 and 10, all 12 pigs in each treatment were paired in 6 new pens to record behavior for a 2-d period and returned to original individual pens. On d 15, pigs were euthanized to obtain hypothalamus. During the first 5 d, ADG and G:F increased (linear, P < 0.01) with increasing supplemental L-Trp. During the entire 15 d, ADG and G:F increased (linear, P = 0.01 and P < 0.01, respectively) with increasing supplemental L-Trp. Estimates of the daily total Trp intake based on ADG on d 15 were 10.8 g/d (P < 0.01; R(2) = 0.16) using a 1-slope broken-line analysis. Hypothalamic 5-HT and 5-hydroxyindoleacetic acid increased (linear, P < 0.01 and P = 0.03, respectively) with increasing supplemental L-Trp. Malonedialdehyde in plasma and hypothalamus, as well as salivary cortisol, on d 15 decreased (linear, P = 0.01, P < 0.01, and P < 0.01, respectively) with increasing supplemental L-Trp. Plasma urea nitrogen decreased (linear, P < 0.01) with increasing supplemental L-Trp. Increasing supplemental L-Trp affected pig behaviors during the first 2-d observation period by decreasing (quadratic, P = 0.04) lying, decreasing (linear, P = 0.04) sitting, and increasing (linear, P = 0.02) drinking. Overall, supplementation of L-Trp improved growth performance of 6 wk-old nursery pigs under social stress in association with increasing hypothalamic 5-HT production, reducing stress hormone concentrations, decreasing lipid peroxidation, increasing drinking, and reducing sitting and lying. Increase in BW gain of nursery pigs under social stress was maximal when daily total Trp intake was 10.8 g.     

饲料中豆粕蛋白替代鱼粉蛋白对花(鱼骨)生长的影响

配制豆粕蛋白对鱼粉蛋白的替代量分别为:0、12.5%、25%、37.5%、50%、62.5%和75%的7种等氮等能的半精制饲料,饲养初始体重为(2.25±0.01)g的7组(三重复)花(鱼骨)6周,以评估花(鱼骨)饲料中豆粕的适宜用量.试验结果表明:豆粕蛋白对鱼粉蛋白替代量为75%饲料组的鱼体末体重和增重率均显著低于其它6组饲料组(P＜0.05),而其它6组饲料组间的鱼体末体重和增重率无显著差异(P＞0.05),各饲料组间花(鱼骨)的存活率、饲料系数、肥满度、脏体比、肝体比及蛋白质积累没有显著差异(P＞0.05),花(鱼骨)全鱼粗脂肪含量随着饲料中豆粕蛋白含量的增加而降低,而豆粕蛋白对鱼粉的替代对全鱼水分、粗蛋白、灰分无显著影响(P＞0.05),本实验花(鱼骨)配合饲料中豆粕蛋白对鱼粉蛋白的最大替代量为625%.     

饵料种类和密度对毛蚶浮游幼虫生长的影响

通过投喂不同种类和不同浓度藻类对毛蚶浮游幼虫的生长进行了研究。结果表明在三种不同的单细胞藻类中湛江球等鞭金藻的效果最好,微绿球藻次之,而小球藻最差。在不同饵料浓度下,表明在初期投喂5×107L-1(cells/L)比较适宜,而后期以10×107L-1比较合适。     

高校学分认定的探索与实践

科学认定学分是保证学分制教学管理科学性的前提之一。目前高校学分认定中存在着学分计量标准不一致、学分认定范围及内容复杂、学分重复认定等问题。高校在学分认定实践中除了应当坚持学分认定原则、完善学分认定管理体系、明确学分认定范围、严格学分认定内容标准、规范学分认定程序和扩大学分认定用途之外,还应统一学分认定标准,明确学分认定目的,加强对学生的指导,完善学分认定档案。     

浅谈长江口区渔业资源增殖放流

进行鱼类育苗放流是改善水域生态环境、恢复渔业资源、保护生物多样性和促进可持续发展的重要途径。但是在各种水域如何选择和确定放流物种，对生态环境和渔业资源保护起着关键作用，本文对长江口区进行增殖放流过程中如何合理选择与安排放流鱼种提出意见．探讨不同生物在同一环境中共同互补生长，实现保持生态平衡、提高养殖效益，进行了可行性探讨。     

饲料企业参与套期保值的意义与方法

1饲料企业参与套期保值的意义1.1从惨重的历史教训说起据中国植物油行业协会提供资料,从2004年5月开始,国内大豆加工业经受着一场严峻考