哈密市奶牛结核病、布鲁氏杆菌病感染情况的调查

结核病与布鲁氏杆菌病都是对人体健康有严重危害的人畜共患传染病。据卫生部门统计，我国现有结核病病人近６００万人，每年因结核病死亡的约２５万人，是单一病菌引起死亡最多的传染病。仅１９９８年第三季度新疆结核病发现人数为 ４ ７９４人，由此可见，此病对人类健康有较大的威胁。而布鲁氏杆菌病同样是人畜共患的全身性传染病，且结核病和布鲁氏杆菌病的传播途径相同，由于人类的结核和畜禽结核有较强的相互交叉感染性，结合我地区实施“放心肉、放心奶”跨世纪“牧业工程”，我们于２０００年春、秋两季对哈密市郊区的５００余头奶牛…     

甲鱼健康快速养殖的几点思考

甲鱼健康养殖就是要求生产者尽量为甲鱼创造良好的生态条件，加强科学饲养管理，使其体质强壮，生长代谢机能及免疫系统正常，不用药或少用药，严禁使用对人体有损害而在鳖体内有储积残留的药物，如孔雀石绿、硝酸亚汞、激素等药物，减少甲鱼发病机率，从而使养成的商品鳖真正成为消费者心目中的“绿色食品”。 快速养殖则是指在健康养殖的前提下，缩短养殖周期，加快资金周转，以其降低成本，提高经济效益。 健康快速养鳖技术的要点： １．种苗 ①选择本地生产的品质优良的杂交种苗，避免近亲繁殖。 近年，亲鳖种质退化、近亲繁殖已成为鳖…     

Effect of heterogeneous digesta chemical composition on the accuracy of measurements of fiber flow in dairy cows.

The objective of the current study was to evaluate the effect of unrepresentative sampling of digesta particulate matter entering the omasal canal on the accuracy of fiber flow measurements. The experimental design comprised one period, one diet, and three cows as experimental units. Within each cow, the physical and chemical composition of digesta particulate matter was assessed at seven sites within the digestive tract. Three Finnish Ayshire dairy cows, equipped with ruminal and simple-T duodenal cannulas, in extended lactation were offered grass silage twice daily on an ad libitum basis. Digesta samples were collected from the rumen (dorsal and ventral sac), reticulum, omasal canal, omasum, duodenum, and rectum to determine particle size distribution in digesta, chemical composition of various particle size fractions, and distribution of two flow markers (Cr-labeled straw and indigestible NDF [INDF]) among particle size fractions. Digesta samples were wet-sieved using sieves of 2.50, 1.25, 0.630, 0.315, 0.160, and 0.080 mm. Particulate matter was analyzed for OM, NDF, and Cr concentrations, and INDF concentration was determined based on 12-d ruminal incubation. The particle size of digesta entering the omasal canal was larger compared with the omasum or the duodenum, suggesting that omasal canal samples were not representative of particle size distribution truly escaping the rumen. The concentration of potentially digestible NDF (PDNDF) decreased with decreasing particle size. The PDNDF concentration of particulate matter retained on all sieves was greatest in the rumen and gradually decreased along the digestive tract. From the reticulorumen to the omasum, the decrease was associated with decreased particle size, reflecting selective passage of particulate matter. In contrast, from the omasum to the duodenum and rectum, the PDNDF concentration decreased within each particle size fraction without effect on particle size, indicating a nonselective passage of particulate matter between these sites. Variation between particle size fractions was slightly greater for Cr concentration than for INDF concentration, indicating that unrepresentative sampling of particulate matter had a greater effect on Cr concentration compared with that of INDF. Owing to unrepresentative sampling, NDF entering the omasal canal was overestimated by 5% using INDF and underestimated by 7% using Cr as a particle phase marker. Of total NDF digestibility, proportionally 0.90, 0.07, and 0.03 occurred in the reticulorumen, omasum, and intestines, respectively. The current results indicate that, despite unrepresentative sampling of digesta particulate matter entering the omasal canal, the errors in determined NDF flow were small. The omasum may have a greater role in postruminal NDF digestion than the intestines.     

拮抗细菌Enterobacter cloaeae B8的一株抗菌素抗性突变体(英文)

为了研究拮抗细菌Enterobacter cloacae B8在野外水稻叶面上的定殖情况及拮抗作用,由自然选择和Tn5诱变从B8产生了一株抗菌素抗性突变体BX8.BX8能在含利福平达400μg/ml或卡那霉素达300μg/ml的LB培养基中生长.实验表明该抗菌素抗性的产生没有降低BX8的拮抗活性.该抗性比较稳定,在无抗菌素培养基中培养.BX8至少分裂生长60代内抗性不变.     

红桔果实粒化机理与控制途径的研究

本文根据果皮组织、果实比重、呼吸强度和乙醇、果胶甲酯酶等的变化,对红桔贮藏中的粒化机理进行了探讨。用植物激素和杀菌剂组成的ZCPⅢ复合保鲜剂作采后浸果处理,对浮皮、粒化和腐烂的防效可达90%以上。     

南美白对虾淡水养殖试验报告

采取人工调兑淡水盐度，定点投喂颗粒饲料，调节水质及病害预防措施，在667m^2淡水池塘中养殖南美白对虾，经107天的饲养管理，共产南美白对虾160．2kg，平均体长达13．5cm/尾，体重20g/尾，成活率达到80．1％，共获利润5732．5元，投入产出比1：2．47。     

Laboratory parameters for the control of the course of therapy of canine Cushing's syndrome]

We compared the results of the ACTH stimulation tests with measurements of alkaline phosphatase and serum cholesterol during Lysodren therapy in 23 dogs with pituitary-dependent hyperadrenocorticism. The ACTH stimulation test proved to be a very sensitive parameter, by which the extent of Lysodren under- or overdosage could be reliably estimated. On the other hand, regulation of the individual Lysodren requirement was not possible by measuring AP and serum cholesterol only. However, it is highly probable that those two parameters can be used to evaluate the general state of metabolism, and they appear to be of prognostic value when greatly elevated.     

北京黑猪和长白猪脂肪代谢的比较

猪在断奶后的生长期内,体内脂肪逐渐增加,和其它家畜相比,猪更倾向沉积体脂。但猪体脂的沉积还要受遗传、年龄、日粮营养水平等因素的影响。在饲粮消化能量(DE)水平保持在3000—3200Kcal/kg,蛋白质含量为14％—15％的饲养条件下,我们分别测定了纯系北京黑猪(肉脂兼用型,平均瘦肉率为51％)和纯系长白猪(瘦肉型猪、平均瘦肉率为62％)的某些脂肪合成酶活性和脂肪代谢的一些生化指标。北京黑猪(公母各半)脂肪组织(背膘)中苹果酸酶(ME),葡萄糖—6—磷酸脱氢酶(G—6—PDH),异柠檬酸脱氢酶(ICDH)三种NADPH—生成酶活性随体重增加而升高,差异极其显著(P<0.001)。体重90kg的酶活性比56kg约高三倍。脂纺组织中上述NADPH生成酶活性北京黑猪比长白猪(体重均为90kg,公母各半)高一倍(P<0.001)。给北京黑猪(30头,公母各半,起始体重为60kg)注谢重组猪生长激素(rPGH,每天每头2mg,连续注谢28天),除表现生长加快,脂肪率下降约21％—23％外,其脂肪组织中NADPH生成酶活性降低十分明显(P<0.001)。苹果酸酶,葡萄糖—6—磷酶脱氢酶,异柠檬酸脱氢酶,三种酶总活性比对照组降低20％。血精中三酰甘油,游离脂肪酸,总胆固醇,高密度脂蛋白(HDL)胆固醇、乳糜微粒,极低密度脂蛋白(VLDL)胆固醇含量,6月龄时,北京黑猪明显高于长白猪(P<0.001—0.0005);而4月龄时,北京黑猪血清中三酰甘油,高密度脂蛋白胆固酶含量则均明显低于长白猪。北京黑猪血清中三酰甘油,高密度脂蛋白胆固醇含量,随月龄(4月龄—6月龄)增长而增加(P<0.0005)。而长白猪则相反,随月龄而呈下降趋势(P<0.05—0.0005)。两种猪的脂蛋白电泳和含量测定未见有年龄和品种间的差异。     

罐顶对罐壁应力的影响

在大型油罐设计中采用线性理论的方法,分析论述了罐顶对罐壁是否产生影响这一问题。通过对拱顶油罐、浮顶油罐的罐壁边界条件、罐顶边界条件的分析计算,求出各层壁板挠度方程中的待定系数,便可得出其应力。从线性方程中,可看出影响罐壁应力的主要因素是挠度方程中的待定系数。待定系数除受储罐尺寸、液位高度的影响外,还受罐顶重量、罐顶剪力和弯矩的影响。以10万m~3浮顶油罐和拱顶油罐为例,进一步证明,液位是罐壁应力的控制因素,而罐顶重量、罐顶剪力和弯矩对罐壁应力的影响可以忽略不计。     

四品种黄牛正常牛体细胞染色体畸变分析

通过淋巴细胞培养对４个黄牛品种共６３头正常牛体细胞染色体的畸变类型和频率进行了观察统计分析。结果表明，蒙古牛，岭南牛和西镇年多倍体细胞出现率分别为４．１２％，４．５７％和５．２１％，平均为４．８７％。多倍体包括三倍体，四倍体和六倍体。结构变异有缺失，染色单体裂隙，染色单体断裂，染色体间隙，染色体断裂和断片几种类型。蒙古牛，秦川牛，岭南牛和西镇牛总的结构变异率分别为２．８７％，２．６５％，１．９４和