皮质醇对黄颡鱼成鱼吞噬细胞和补体活性的影响

采用皮质醇混饲投喂的方法．模拟自然条件下的慢性应激,研究皮质醇对黄颡鱼咸鱼吞噬细胞呼吸暴发和血清补体旁路溶血活性（ACH50）的影响。研究结果与结论如下。皮质醇混饲投喂可使血清皮质醇浓度持续显著升高,各周对照组血清皮质醇含量均无显著性差异,证明采用皮质醇混饲投喂的方法可模拟自然慢性应激情况下的血清皮质醇浓度持续显著升高。从第2周开始头肾吞噬细胞的呼吸暴发功能显著下降（P〈0．05）,证明皮质醇对头肾吞噬细胞的杀菌能力产生显著抑制作用。10mg／kg剂量组,ACH50在投喂第2、第5、第6周显著低于对照组（P〈0．05）,100mg／kg剂量组,ACH50从第2周开始一直都极显著低于同期对照组（P〈0．01）,证明皮质醇显著抑制血清补体旁路溶血活性,且血清皮质醇浓度越高其抑制作用越强。     

食品化学开放式实验教学和考核体系改革探讨

为了深化专业基础平台课程实验教学改革、全面提高学生独立发现问题及解决问题的能力,满足社会对食品类具有较高实际动手能力人才的需求,根据浙江林学院近年实验教学改革的经验,建立了完善的开放式实验教学运行模式,为同类课程的实验教学改革提供参考。另外在实验考核体系的改革中,为了充分发挥学生学习的主动性,使学生在实验教学过程中能够更加主动地、独立地、积极地进行思考,提升了学生在实验教学中的主体地位,培养了学生的独立人格及综合创新能力,进一步提高了教学质量。     

添加剂赐力健对肉牛生长性能、消化率及血清生化指标的影响

分析添加剂赐力健对肉牛生产性能、消化率及血清生化指标的影响。将体重((441.85±75.30)kg)相近的20头((19.0±0.8)月龄)西门塔尔与北方黄牛的杂交后代公牛(西杂牛)随机分为4组,在90d内分别饲喂含赐力健添加剂为(w)0(CK)、0.5‰、1.0‰和2.0‰的日粮。结果显示:1)1.0‰处理的平均日增重显著高于其他各组(P<0.05);2)各处理的粗纤维和ADF消化率与苹果酸脱氢酶(MDH)活力和总抗氧化能力水平(T-AOC,总抗)均显著高于对照(P<0.05);3)各处理的血清脂肪酶活力(LPS)和尿素氮(BUN)含量均显著低于对照(P<0.05)。由此可见,添加剂赐力健能提高西杂牛的平均日增重和饲料消化率,改善脂肪酸代谢,特别是在含量1.0‰时效果显著。     

Effects of feeding frequency and dietary protein levels on juvenile allogynogenetic gibel carp (Carassius auratus gibelio) var. CAS III: growth,feed utilization and serum free essential amino acids dynamics

A 8 week growth trial of three feeding frequencies (2, 4 and 6 meals day^?1) and three dietary protein levels (30%, 34% and 38%) was conducted to investigate the influence of feeding frequency and dietary protein level on growth, feed utilization, serum free essential amino acids (EAA) dynamics and nitrogen (N), phosphorus (P), carbon (C) retention in juvenile allogynogenetic gibel carp (Carassius auratus gibelio) ‘CAS III’. The results showed that feeding frequency and dietary protein level increased feed intake (FI), specific growth rate (SGR) and feed efficiency (FE). SGR increased significantly with the increase in feeding frequency and dietary protein level. But, the increase in dietary protein level from 30% to 38% in group 6 meals day^?1 did not result in better growth. Compared with the group of 4 meals day^?1 × 38%, the fish fed the diet containing 30% crude protein at 6 meals day^?1 obtained similar SGR but showed lower FIp (protein intake). Compared with 2 meals day^?1, NREs (nitrogen retention efficiency) of 4 and 6 meals day^?1 were relatively higher. PRE (phosphorus retention efficiency) and CRE (carbon retention efficiency) increased significantly with feeding frequency while TNW (total nitrogen waste output), TPW (total phosphorus waste output) and TCW (total carbon waste output) decreased significantly. Feeding frequency and dietary protein level increased trypsin activity. Serum free EAA concentrations varied more synchronously at 6 meals day^?1 than 2 meals day^?1. It could be concluded that increasing feeding frequency could improve growth by increasing feed intake and feed efficiency for juvenile gibel carp. The increase in feeding frequency showed protein‐sparing effect.     

Effects of stocking density on mortality,growth and physiology of juvenile Amur sturgeon (Acipenser schrenckii)

To evaluate effects of stocking density on welfare of Amur sturgeon (Acipenser schrenckii), an experiment was designed using three initial stocking densities in flow‐through tanks (LSD = 3.7 kg m^?3, MSD = 6.9 kg m^?3, and HSD = 9.3 kg m^?3, respectively) for 60 days. Growth, body composition, and haematological and biochemical parameters were monitored. The mortality and feed conversion rate (FCR) were not affected by stocking density. However, the specific growth rate (SGR), final weight and weight gain in the HSD group were significantly lower than in the LSD and MSD groups. The hepatosomatic (HSI) and viscerosomatic indices (VSI) varied inversely with regard to stocking density. Stocking density did not affect crude protein levels in fish. In contrast, the total lipid level was significantly higher in the LSD group compared to the MSD and HSD groups. The levels of erythrocytes and haemoglobin were positively correlated with stocking density. Serum total bilirubin and urea in HSD group were significantly higher than in the LSD group while serum triglycerides showed opposite tendencies. Differences between treatments were not registered for glucose, total protein and albumin. In conclusion, higher stocking density resulted in increased immunosuppression and enhanced energy mobilization. The latter was necessary to enable Amur sturgeon to cope with crowding.     

不同精粗比日粮对杜泊绵羊生长性能、血清生化指标及经济效益的影响

为探讨不同精粗比日粮对不同生理阶段杜泊绵羊生长性能、血清生化指标及经济效益的影响,本研究进行了2个试验。试验Ⅰ:选用体重20~35 kg断奶杜泊羔羊40只(公、母各半),随机分成4组,每组10只,分别饲喂精粗比为40:60 (A组)、50:50 (B组)、60:40 (C组)、70:30 (D组)的日粮,试验期70 d;试验Ⅱ:选用体重30~45 kg生长期杜泊羊40只(公、母各半),随机分成4组,每组10只,分别饲喂精粗比为35:65 (E组)、45:55 (F组)、55:45 (G组)、65:35 (H组)的日粮,试验期70 d。结果显示,试验Ⅰ:①随日粮精料比的增加,断奶杜泊公羊的平均日增重呈现增加趋势,而母羊为先增加后降低,总体A组显著低于其他3组(P<0.05),B、C、D组间差异均不显著(P>0.05);随日粮精粗比的增加,各组平均日采食量逐渐降低且差异显著(P<0.05),各组公羊料重比显著降低(P<0.05),而B组母羊料重比显著低于其他3组(P<0.05)。②各组试验羊血清中总蛋白、甘油三酯、血糖含量差异均不显著(P>0.05),而日粮精粗比对其他血清成分有不同的影响。③D组公羊平均日净利润比B、C组分别高53.02%、35.33%,B组母羊平均日净利润比C、D组分别高61.76%、54.49%。试验Ⅱ:①随日粮精料比的增加,生长期杜泊绵羊平均日增重基本呈现显著增加趋势(P<0.05),而G组母羊平均日增重最高且显著高于E组(P<0.05),F、G、H组间差异不显著(P>0.05)。随日粮精粗比的增加,各组平均日采食量逐渐降低(P<0.05),公羊的料重比逐渐降低(P<0.05),而母羊料重比呈现先降低后增加趋势,G组显著低于其他3组(P<0.05)。②日粮精粗比对各组试验羊血清中总蛋白、甘油三酯、血糖含量影响差异均不显著(P>0.05),而对其他血清成分有不同的影响。③H组公羊平均日净利润比F、G组分别高69.49%、52.13%,G组母羊平均日净利润比F组高1 282.61%。综合各项指标分析,断奶杜泊公羔羊日粮精粗比以60:40较好,断奶杜泊母羔羊精粗比以50:50较好,断奶羔羊混群饲养,日粮精粗比为50:50较宜;生长期杜泊绵羊日粮精粗比均为55:45较适宜。     

K亚群禽白血病病毒gp85单因子血清的制备及其特异性鉴定

为了制备一种快速特异性识别K亚群禽白血病病毒(ALV-K)的单因子血清,本试验将ALV-K接种DF1细胞,提取感染细胞DNA作为模板,PCR扩增1 005 bp ALV-K-gp85和510 bp ALV-K-gp85(fragment)基因.将其正确的阅读框插入表达载体pET-28a(+)中,转化大肠杆菌BL21(Rosetta)菌株中表达.将表达蛋白常规免疫昆明白小鼠制备抗血清.结果表明成功获得39.85和22.01 ku的重组融合蛋白,且具有良好的免疫原性.间接免疫荧光试验(IFA)结果表明两血清均可与ALV-K反应,而不与ALV-A、ALV-B和ALV-J反应.本试验首次研制获得能特异性识别ALV-K的单因子血清,为K亚群禽白血病的快速检测奠定了基础.     

沂沭河下游平原地下水TDS和水化学类型的分布规律

在对沂沭河下游平原212组地下水化学样品进行分析的基础上,总结出研究区不同循环深度地下水TDS和水化学类型的空间分布:1北部丘岗区地下水以淡水为主;东部滨海平原区浅层地下水几乎均为微咸水和咸水;深层承压水以淡水和微咸水为主,微咸水分布于沿海大部分地区和内陆的滨海县附近,沿海地区洋桥农场、图河乡一带以及东南部八滩乡的深层地下水为淡水。2北部丘岗区地下水化学类型单一;东部滨海平原区浅层地下水化学类型具有水平分带规律;深层承压水化学类型总体上由陆向海存在水平分带规律,洋桥农场、图和乡及八滩镇的水化学类型与沿海咸水区地下水化学类型存在差异。     

中国西北戈壁地区12条河流水文水质调查

2014年9月对我国塔里木盆地南缘与柴达木盆地戈壁地区的12条典型河流进行实地调查,通过野外采集水样、测定流速、室内查阅资料和化验分析,获得了研究区河流的最新水文水质资料。结果表明:(1)戈壁地区修建的水库和防渗渠道,对河流正常发展产生了不利影响;(2)水样中的F-含量均超过1mg/L,不能满足人们直接饮用的要求,F-与Ca2+含量呈现负相关关系;(3)水样中阳离子浓度大小关系为Ca2+Na+Mg2+K+,水化学类型总体上为氯化物·硫酸盐·碳酸氢盐/钠质·钙质水;(4)水样的TDS变化范围在718.3~8 254.1mg/L,含量普遍偏高,水样pH变化范围在7.44~8.07,表现为弱碱性。     

Design and Validation of an Assay for Isotope Ratio Mass Spectrometry Analysis of Biologically Relevant Dissolved and Heat-Extracted Organic Carbon with Neutral Potassium Phosphate Buffer

Labile soil dissolved organic carbon (DOC) and heat-extracted carbon (HEC) are sensitive indicators of changing soil organic carbon (SOC) stocks. Isotope ratio mass spectrometry (IRMS) is an important tool for studying SOC turnover and soil biological function. Several complications are involved in measuring DOC/HEC, for example salt ionic strength; solution pH; and anionic damage to elemental analyzer-IRMS. We evaluated a method for DOC/HEC analysis with 0.1 M potassium phosphate buffer (PPB). This method was strongly correlated with commonly used carbon (C) extractants for C quantification. Carbon-13 comparisons between DOC/HEC extracted with Milli-Q water and PPB were similar. The δ¹³C (‰) values of particulate OC and DOC were similar, whereas the relationship between humic OC and HEC was soil specific. An incubation experiment demonstrated that DOC/HEC δ¹³C (‰) successfully explained respired microbial carbon dioxide over 90 days. We conclude that this method represents an alternative for DOC/HEC quantification and δ¹³C (‰) analyses.