绵羊宿营法防除天然草地灌木杂草研究Ⅴ新鲜羊粪尿对土壤可交换性氮和植物生长的影响

绵羊新鲜粪尿对土壤和植物氮转化与含量影响的结果表明 ,0～ 10 cm土壤可交换性铵态氮在绵羊宿营之后即达到最大值 ,然后逐渐下降。 10～ 2 0 cm土层最大值出现要迟半个月。绵羊宿营(UDT)处理、尿 (U)处理和粪尿 (UD)处理的土壤铵态氮浓度都较高。土壤中出现高浓度可交换性铵态氮与游离氨的相互转换 ,可能形成高浓度的游离氨 ,对植物产生一定毒害。土壤可交换性亚硝态氮在 7月 30日之前变化呈波浪型 ,说明一部分亚硝态氮迅速转化为硝态氮 ,一部分被植物吸收 ;7月 30日后 ,土壤亚硝态氮快速积累 ,形成高浓度 ,对植物产生毒害作用。土壤可交换性硝态氮与亚硝态氮的变化相关显著。植物体内粗蛋白质含量的变化表明 ,在 7月 30日前无变化或有所下降 ,而 7月 30日后迅速上升 ,但时间较短 ;至 8月 11日即不再上升而开始下降。植物体内粗蛋白质的两次下降是植物受到氨和亚硝态氮毒害的结果     

糠尿分析试纸法测定十字花科蔬菜种子生活力

采用“糠尿分析试纸法”测定20种十字花科蔬菜种子生活力,并与TTC法及实验室发芽率对照进行相关分析。结果表明, “糠尿分析试纸法”所测种子渗出液中葡萄糖含量与种子生活力、室内发芽率呈负相关;种子渗出液中葡萄糖含量越高,生活力越弱,发芽率越低。采用该法测定种子生活力快速简便。     

日粮阴阳离子水平对奶牛血液生化指标和尿液指标的影响

选择泌乳中期奶牛20头,随机分成4组,分别饲喂不同阴阳离子水平(DCAB)日粮,DCAB分别为87(对照)、300、400和500mEq/kg DM,测定了不同DCAB对血清和尿液一些指标的影响。血液指标中,DCAB 400组提高了促乳素,DCAB 400和500组提高了雌二醇浓度和尿素;DCAB 300和400组乳酸脱氢酶、肌酸磷酸激酶和总蛋白显著提高;处理组钙含量显著高于对照组。尿液指标中,DCAB 400和500组pH显著高于对照组,钾离子浓度显著低于对照组;处理组氯离子浓度均显著低于对照组,而DCAB 300和500组钠离子显著提高;DCAB 400组尿素显著高于对照组。本研究条件下,DCAB400mEq/kg DM是泌乳期奶牛较为适合的日粮添加量。     

鸡的尿液收集及其理化性状分析

本试验给 4只成年母鸡作了输尿管引出手术 ,采用自制的接尿装置定时收集鸡的尿液 ,对其进行常规理化检验和部分化学成分测定。试验结果表明 :1输尿管引出手术结合特制接尿装置是收集鸡纯净尿液的好方法 ;2鸡正常尿液呈淡黄色 ,混浊而有较多白色沉淀 ,p H6 .2～ 7.4,比重 1 .0 1 0～ 1 .0 2 5 ,酮体、尿糖、潜血常规检验均为阴性 ,尿蛋白呈阳性反应 ,尿酸含量 ( 380 .1 2± 74.97) mg/1 0 0 m L ,钙含量 ( 30 .2 9± 6 .5 4) mg/1 0 0 m L,磷含量 ( 8.6 2± 1 .84) mg/1 0 0 m L,尿沉渣中以尿酸、尿酸盐、硫酸钙结晶为主 ,鸡排尿量平均 ( 5 5 .43± 1 1 .95 ) m L/6 h。     

Disposition kinetics,urinary excretion and dosage regimen of kanamycin in buffalo calves following single intravenous administration

The disposition kinetics and appropriate dosage regimen for kanamycin were investigated in buffalo calves following a single intravenous dose of 10 mg/kg body weight. The distribution and elimination half-lives were 0.12±0.01 h and 1.94±0.11 h, respectively. The apparent volume of distribution and total body clearance were 0.2±0.01 L/kg and 92.9±3.69 ml/kg/h, respectively. About 74% of the administered dose was excreted in urine in 24 h. A suitable dosage regimen for the intravenous administration of kanamycin was also calculated.Abbreviation SEM standard error of the mean     

Renal hemodynamic and diuretic effects of low-dosage dopamine in anesthetized cats

Objective: To evaluate the effects of low‐dosage (3 μg/kg/min) dopamine on urine output, renal blood flow, creatinine clearance, sodium excretion, heart rate, and mean arterial pressure (MAP) in healthy anesthetized cats. Design: Controlled experimental study. Setting: University experimental laboratory. Animals: Twelve random‐bred 2–4‐year‐old cats. Interventions: Anesthesia, laparotomy for renal artery blood flow measurement, and arterial and venous catheterization. Measurements: Heart rate (HR), MAP, renal blood flow, urine output, sodium excretion, fractional sodium excretion, and creatinine clearance. Main results: No significant difference in urine output, sodium excretion, HR, or creatinine clearance occurred in cats receiving low‐dosage dopamine. A transient decrease in the mean arterial blood pressure occurred in cats receiving dopamine. Conclusions: Low‐dosage dopamine cannot be expected to induce diuresis in healthy cats. Low‐dosage dopamine may cause vasodilation in non‐renal vascular beds.     

应用GC-MS测定动物组织及尿中克仑特罗残留

对酶联免疫法筛选检出的阳性猪肝和猪尿样品应用GC-MS法进行了确证试验,分析了操作中衍生化、质谱参数的设定、溶剂的干扰、进样及谱库的检索等因素对测定结果的影响,说明了应注意的问题并提出了解决问题的方法,可供残留分析工作者参考.     

Chemical Characterization of Bovine Urine with Special Reference to Oestrus

Cows' urine was analysed by gas chromatography–mass spectrometry (GC-MS). The profiles from preovulatory, ovulatory and postovulatory samples were compared to establish any qualitative and quantitative differences that might have potential value in olfactory communication. Dichloromethane was used as the solvent for extraction of the compounds. Seven different compounds were detected, of which only two were common to all the chromatograms. The chemical profile of oestrous urine was distinguished by the presence of two specific compounds, viz. di-n-propyl phthalate and 1-iodoundecane, that were not found in the other samples. As oestrous urine has been shown to elicit sexual behaviour in cattle, these two characteristic peaks may represent important chemical compounds that elicit signals that allow the bull to detect `oestrous odours'.     

Hydrocortisone Concentrations in Post-Race Urine from Horses

As hydrocortisone is an endogenous substance, it is first necessary to establish its normal concentrations so as to be able to control its use in racing animals. This study was designed to establish the hydrocortisone concentrations in post-race urine samples of horses racing in Brazil and also to evaluate the results in relation to the international threshold set for this drug. Urine samples were analysed by HPLC-UV. The results were evaluated according to the concentration range as well as sex and time of sample collection (afternoon or evening races). The results showed a high degree of variation in the concentrations of hydrocortisone in the urine (93±69 ng/ml). The maximum concentration observed was 646 ng/ml, although only a few horses (around 1%) showed levels within the range 500–650 ng/ml, 91% being in the range 0–150 ng/ml. The data suggested a normal distribution curve. Statistical analysis showed no significant influence of sex or time of sample collection.     

Effects of 105 traditional Chinese medicines on the detection of β-agonists in medicine extracts and swine urine based on colloidal gold immunochromatographic assay

Colloidal gold immunochromatographic assay(CGIA) is commonly used for the on-site detection of β-agonists that are sometimes used illegally as feed additives in swine diets. However, few studies have evaluated the causes of false-positive results that sometimes occur when applying CGIA in agricultural settings. In this study, we investigated if this false-positive phenomenon is related to the addition of certain traditional Chinese medicines(TCMs) to swine feed. We established and verified an extraction method for TCMs, and then applied CGIA to detect β-agonists in the extracts of 105 TCMs and in the urine of swine dosed with TCMs, respectively. Liquid chromatography-tandem mass spectrometry was used to validate the results of the urine samples tested positive for β-agonists using CGIA. The results were also verified using TCMs and colloidal gold test strips produced by different manufacturers. The extracts of Citri Reticulatae Pericarpium Viride, Citri Reticulatae Pericarpium, Magnoliae Officinalis Cortex, Chaenomelis Fructus, and Rhodiolae Crenulatae Radix Et Rhizoma were tested positive for β-agonists. Meanwhile, the addition of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium to swine feed resulted in false-positive results for β-agonists in swine urine. The results provide a new way to explain false-positive CGIA results and provide valuable information for livestock feeding programs.