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71.
用堆型艾美耳球虫早熟株对雏鸡进行一次免疫和二次免疫试验 ,研究雏鸡血清抗体的动态变化。试验结果显示 ,在一次免疫试验中 ,各剂量组雏鸡均在免疫后 2天血清抗体出现较高的 OD值 ,之后呈下降趋势 ,11天后逐渐上升 ,到 12~ 13天时出现第 2个峰值 ,各组间的血清抗体 OD值比较 ,3 0 0 0个卵囊 /只剂量组极显著 (P<0 .0 1)高于 10 0 0个 /只、2 0 0 0个 /只和 5 0 0 0个 /只剂量组。在二次免疫试验中 ,8日龄首免、14日龄二免组雏鸡的抗体水平动态变化整体呈上升趋势 ,峰值 (0 .3 75 )出现在二免后第 10天 ,其后稳定地维持在较高水平 (平均 OD值为 0 .3 5 ) ,并且其抗体水平显著地高于 6日龄首免、12日龄二免组 (P<0 .0 5 )。抗体水平动态变化表明 ,堆型艾美耳球虫早熟株有较强的免疫保护力 ,其免疫方式可选用一次免疫 ,剂量为 3 0 0 0个卵囊 /只 ,也可采用二次免疫 ,即 8日龄首免 (15 0 0个 /只 ) ,14日龄二免 (15 0 0个 /只 ) ,从抗体动态变化的稳定性看 ,二次免疫更佳 相似文献
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73.
对天津市设施农业的现状分析及展望 总被引:1,自引:0,他引:1
设施农业又被称为工厂化农业,具有强大的生命力和广阔的发展前景,是农业可持续发展的重要内容之一.同时也是加速我国农业工程化进程,成为促进我国传统农业向现代化农业发展的必由之路。 相似文献
74.
B Cancho Grande M S García Falcón M Rodríguez Comesa?a J Simal Gándara 《Journal of agricultural and food chemistry》2001,49(7):3145-3150
Sulfamethazine (SMZ) and trimethoprim (TMP) are antibacterials used in veterinary practice. This paper describes a method for their determination in veterinary liquid feed premixes that is based on liquid chromatography with diode array detection. Gradient elution with methanol and ammonium acetate achieved excellent separation of the two analytes within 15 min without any interference from the matrix. Absorbance of the column effluent was monitored at 264 nm for SMZ and at 230 nm for TMP. Detailed analyses of the uncertainties of determinations afford estimated expanded uncertainties of, respectively, 0.2 and 0.1 w/v % for typical SMZ and TMP concentrations of 10.7 and 2.1 w/v %, respectively. At the lower end of the calibrated range of the method, the dominant source of uncertainty is the preparation of standards and the construction of the calibration line. 相似文献
75.
W Rabsch A Liesegang H Tsch?pe 《Berliner und Münchener tier?rztliche Wochenschrift》2001,114(11-12):433-437
The Paul Ehrlich Institute, Langen, in Germany has been licensed different live vaccines of S. Typhimurium and S. Enteritidis for use in the veterinary medicine since I the 90s. The Robert Koch Institute has established a lab-based surveillance system for these live vaccine strains for an evaluation of recent public health safety. Since 2000 all strains of S. Typhimurium and S. Enteritidis from humans were investigated in respect to their phage types and other vaccine markers. 3676 S. Typhimurium strains and 4489 S. Enteritidis strains mainly from Salmonellose patients were investigated after phage typing according to their auxotrophic or antibiotic resistance markers. The live vaccine strains of Zoosaloral, TAD Salmonella vacT or TAD Salmonella vacE and Salmovac SE could not be found from infections in humans. 相似文献
76.
The influence of an eradication programme for lice on the prevalence of light flecks and spots on cattle hides was studied in 33 dairy cattle herds during a period of two and a half years. Lice were eradicated from the main group of herds after 9 to 12 months and the quality of the hides before and after treatment was compared. Hides from slaughtered animals were collected during the study period, tanned and examined with special emphasis on the occurrence of the grain damage light flecks and spots. The prevalence of hides without light flecks and spots increased from 24.2% before treatment to 61.6% after treatment. The prevalence of hides free from the damage increased significantly in all examined anatomical regions. The improvement in hide quality was most marked in the shoulders and neck region which corresponded to the major predilection site of cattle lice. The prevalence of hides with light flecks and spots started to decrease in the first period (2-40 days) after eradication. The changes after treatment suggested that most healing process took place over a period of about 4 months. The eradication programme eliminated the seasonal variation in the prevalence of light flecks and spots which was present before treatment. 相似文献
77.
T Kokkonen A Tsehai Tesfa M Tuori S Yrj?nen L Syrj?l?-Qvist 《Archives of Animal Nutrition》2002,56(3):213-227
Twenty-one multiparous dairy cows were fed concentrates containing three levels (119, 154 and 191 g/kg DM) of crude protein (CP) during the first ten weeks of lactation. Part of the grain and molassed sugar beat pulp was substituted with 0% (RSM0), 15% (RSM15) or 30% (RSM30) repeseed meal. Wilted grass silage was fed ad libitum after calving. The average response between RSM0 and RSM15 was +1.66 kg milk/d per percentage unit change in concentrate CP content. No further response occurred between RSM15 and RSM30. The positive effect of RSM inclusion was seen throughout the experimental period and was associated with increased plasma non esterified fatty acids (NEFA) and decreased plasma insulin concentration one week after calving, and higher efficiency of metabolisable energy utilisation for milk production. Digestibility of the diet remained unaffected. Milk and plasma urea tended to increase with RSM30 indicating excessive supply of rumen degradable protein. Because of the limited potential of cows to compensate for a deficit in feed protein supply by mobilising tissue protein, a substantial milk yield response can be achieved with a moderate level of protein supplementation during early lactation. 相似文献
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80.
西藏沙化动态及其原区 总被引:1,自引:0,他引:1
西藏自治区是我国沙化最严重的地区之一。2004年调查结果表明,西藏沙化面积为216842.7km^2其中重度以上的沙化面积占总沙化面积的91.53%;沙化类型以戈壁占绝对优势:草地、未利用地是主要的沙化土地利用类型。全区沙化总体上呈恶化趋势,沙化土地面积增加,沙化程度加剧,但拉萨、山南等地沙化土地有所减少。西藏土地沙化变化是受自然因素与人为因素共同作用的结果。 相似文献