高效液相色谱法同时测定干菊花中五种防腐剂

建立了同时测定干菊花中5种防腐剂的高效液相色谱分析方法,优化后的色谱条件为采用Waters XTerra C18色谱柱(3.9 mm×150 mm,5μm)分离,流动相为乙酸水溶液(0.1%)/甲醇梯度洗脱,用二极管阵列检测器在波长254 nm处进行检测。结果表明,5种防腐剂在18 min内可获得较好的分离效果,在0.1~20.0 mg/L范围内线性关系良好(r≥0.999 8),检出限为0.001 5~0.059 0 mg/L,定量限为0.005 0~0.196 8 mg/L,加标回收率为85.9%~97.8%,RSD为0.5%~12.5%。该方法操作简单、灵敏度高、重复性好,可用于检测干菊花中防腐剂。     

Effect of dietary inclusion of spray‐dried porcine plasma on performance,some physiological and immunological response of broiler chickens challenged with Salmonella sofia

This study was conducted to investigate the effect of spray‐dried porcine plasma (SDPP) in broiler chickens under Salmonella sofia disease challenge. The experiment comprised five starter diets: positive control (no supplement), diet supplemented with in‐feed antibiotics (IFA; salinomycin 0.05% + zinc bacitracin 0.033%) and diets supplemented with SDPP at 10 or 20 g/kg diet. All four of these groups were challenged with S. sofia, while a fifth group was unchallenged and used as the negative control. The experimental diets were fed to 14 days; then, the birds were switched to commercial‐type grower and finisher diets. Oral inoculation of the challenged groups with S. sofia occurred on day 8, 10 and 12. Body weight was significantly higher in the birds fed diets containing IFA and SDPP than in the challenged control group, but it was only significant in starter and grower phases. In general, there was an improvement in the weights of the immune‐related organs, but it was only significant for the weight of the bursa of SDPP‐fed birds at 13 days. At day 13, blood potassium content was lower and the concentrations of IgG and IgM tended to be lower in the birds fed on low‐SDPP starter diets than those of the other groups. There were significant differences in the concentration of lactic acid in the ileum and acetic acid, formic acid, butyric acid and propionic acid in the caeca. Inclusion of SDPP to the starter diets of broiler chicks had positive effects on broiler performance, immunity and gut health during exposure to highly pathogenic conditions.     

A STUDY ON HEAT AND MOISTURE STATE OF HULL LAYER FOR THERMAL INSTULATION OF A COLD STORAGE

This paper analyses the thermal moist characteristics of the hull layer beside an air layer at lower temperature in an envelope for a cold storage and presents a new method of waterproof by air layer. With test data from engineering practice, the theory on the barrier of self moisture proof at the surface sublayer of the hull layer in an attic on a cold storage is proven. The dried zone about three phase point is confirmed. It is a new knowledge for thermophysics on thermal design of a cold storage with an optimum thermal performance.     

代乳料原料组成对早期断奶羔羊生长及脏器发育的影响

为了探讨代乳料原料的不同组合效应对早期断奶羔羊的饲喂效果,选取25只甘肃高山细毛羔羊,分为5组,每组5只,对照组羔羊由母羊自由哺乳和放牧;试验组羔羊30日龄断奶,饲喂4种代乳料:A组主原料未膨化,B组主原料膨化,C组主原料膨化+血浆蛋白粉,D组在C组基础上增加乳清粉。试验期为30~90日龄。结果表明:50、70日龄时,对照组羔羊体质量最大,试验组羔羊受断奶应激的影响,相应指标较小。90日龄时,D组体质量显著高于B、C组(P0.05),超过了对照组。30~90日龄阶段,D组日增体质量最大,且显著高于B、C组(P0.05)。对照组脾脏质量显著高于4个试验组(P0.05),且脾脏指数最高。说明在代乳料中添加血浆蛋白粉及增加乳清粉,有利于羔羊健康发育,使代乳料的饲喂效果最佳。     

烘干鸡粪作为蛋白质饲料的应用研究

把采集的新鲜鸡粪运用先进合理的加工工艺烘干后，作为一种蛋白质饲料加入畜禽的日粮中，具有无毒、适口性好、转化率高、价格低廉等优点，通过试验表明可部分取代植物性蛋白质饲料，从而降低养殖成本。鸡粪作为一种环境污染源，在环境保护呼声越来越高的今天，鸡粪通过先进合理的加工处理可制成优质饲料，又可加快社会环境的综合治理步伐，具有巨大的经济效益、社会效益、生态效益。     

半干旱黄土丘陵区小流域横断面土壤水分生态特征

在半干旱地区甘肃榆中北部中连川流域取一横断面,根据地形部位与利用条件布设11个测点,用土钻法监测土壤水分剖面分布与动态,测深到5m。各立地条件年内4月到12月土壤水分动态趋势多样。流域横断面的土壤湿度均较低,2～5m平均值一般都小于10％,其中以坡地苜蓿与半阳坡柠条林地最干燥。该地区土壤干燥化层是普遍存在的,不仅存在于人工植被,也存在于天然植被。径流富集叠加可显著改善土壤水分状况,隔坡水平梯田是其重要途径。退耕还草中要考虑各类草地的比例、苜蓿种植的适宜规模及其持续性问题。     

喷雾干燥鱼浆蛋白粉营养成分分析

本试验对鱼粉加工废水鱼浆蛋白粉(经浓缩、水解、喷雾干燥得到的副产品)进行营养成分分析,其中粗蛋白质含量达64.08%,钙2.67%、磷1.12%,钙磷比例合理;各氨基酸含量分别为:赖氨酸3.29%,蛋氨酸0.94%,谷氨酸5.17%,牛磺酸2.50%。     

True Metabolizable Energy and Amino Acid Digestibility of Distillers Dried Grains with Solubles

In recent years, policies encouraging the production of ethanol have stimulated an enormous increase in the production of distillers dried grains with solubles (DDGS). The form of the ingredient that is becoming increasingly available differs from that of previous decades in that it is derived almost entirely from corn and is dried under less severe conditions. Seventeen DDGS samples were obtained from 6 different plants in the midwestern United States from 2002 to 2004. Each sample was analyzed for TME_n, and 8 representative samples were analyzed for total and digestible amino acids (AA) by the precision-fed rooster assay using conventional or cecectomized Single Comb White Leghorn roosters, respectively. Color [lightness (L*), redness (a*), and yellowness (b*)] of each DDGS sample was measured with a Minolta Chroma Meter CR-300. The TME_n ranged from 2,490 to 3,190 kcal/kg (86% DM basis) and had a mean of 2,820 kcal/kg. Variation was noted among samples, presumably reflecting differences in the original corn composition, fermentation, and disposition of solubles. Considerable differences were observed among the true AA digestibilities of the DDGS samples. Most samples were golden in color, and true AA digestibility values were relatively consistent among these samples. The average total concentration and digestibility coefficients of several most limiting AA for the 8 DDGS samples were as follows: Lys, 0.71% (70); Met, 0.54% (87); cystine, 0.56% (74); Thr, 0.96% (75), Val, 1.33% (80), Ile, 0.97% (83); and Arg, 1.09% (84). Correlations were found among digestible Lys, Thr, Arg, His, and Trp and the yellowness (b*) and lightness (L*) of the DDGS samples. In general, DDGS samples that were more yellow and lighter in color had higher total and digestible AA levels. The variation in TME_n and AA digestibility observed among samples strongly indicated that confirmatory analyses should be conducted prior to using samples from a new supplier.     

用绵羊小肠液冻干粉测定饲料过瘤胃淀粉小肠消化率方法的研究

本试验旨在以玉米为样本筛选用绵羊小肠液冻干粉测定精饲料瘤胃非降解残渣淀粉小肠消化率的最佳培养条件。分别研究了小肠液冻干粉用量(0.2、0.3、0.4、0.5和0.6g)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响;离体培养时间(4、8、12、16、20和24h)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响。结果表明,在本试验条件下,绵羊小肠液冻干粉测定玉米瘤胃非降解残渣淀粉小肠消化率的最佳用量为0.45g小肠液冻干粉/0.56g玉米瘤胃非降解残渣,最佳培养时间为12h。利用绵羊小肠液冻干粉测定常用饲料过瘤胃残渣淀粉小肠消化率的方法是可行的。