兽药内服制剂的微生物污染对食品动物健康及兽药临床

为考察兽药中实际存在的微生物对动物健康的影响,对山东省兽药GMP企业生产的粉散剂、颗粒剂产品的微生物污染状况进行抽样调查检测,发现不同的内服给药制剂,其微生物污染水平结果差异显著。在此基础上选择微生物限度严重超标的中药散剂,从中分离细菌、霉菌,拟定不同菌量的污染水平对健康鸡进行饲喂试验。结果表明：试验期间各用菌组试验鸡的精神状况、饮水和采食均未发现异常,试验结束后剖检各用菌液组及空白对照组鸡的心、肝、肾、肠道等,均未发现异常,各组鸡均未出现发病与死亡情况,且各组间增重无显著性差异（P〉0．05）。为进一步考察兽药被微生物污染后对临床疗效的影响,选用微生物限度严重超标的中药散剂鸡康灵微粉,开展对鸡慢性呼吸道病治疗试验,将自然感染鸡随机分为两组,每组1600只,一组鸡服用微生物限度超标的鸡康灵微粉,另一组服用辐射灭菌后的鸡康灵微粉。结果表明：两组治愈率均达90％以上,经x。检验,无显著性差异（P〉0．05）,产蛋率均恢复到90％以上。由上述试验可见,兽药不同内服制剂的微生物污染差异显著,且不同的微生物污染水平对动物健康及兽药临床疗效无显著影响,其相关性有待进一步研究。     

Effect of cattle management practices on raw milk quality on farms operating in a two-stage dairy chain

In many developing countries, milk production varies greatly according to farm size, cattle breed, and milking practices. However, production systems often are dominated by smallholder farms. Therefore, relatively small volumes of milk are delivered daily from numerous farms to intermediate cooperatives which supply industrial units. This paper argues that in such two-stage dairy chains, milk quality could be improved by focusing on farming practices rather than on the testing of individual deliveries. Indeed, it is difficult to analyze their quality due to technical, economic, and logistic limitations. The objective of this study is to link on-farm practices with milk chemical quality parameters (fat and protein) and hygienic quality criteria (Aerobic Plate Count, APC and Coliforms). Cattle management practices were monitored monthly over one year on 23 farms located on an irrigation scheme in Morocco. 276 milk samples were analyzed. The monthly variability of milk quality parameters was then characterized. Results show that average cow milk chemical parameters vary within a normal range. They remain primarily linked to the genetic type of cows, the lactation stage, and the conversion of feed concentrates’ net energy into milk. Overall milk hygienic quality was poor (APC and Coliforms counts were 100 fold international norms), due essentially to a lack of hygiene and inadequate milking conditions (hands, udder, and teat washing, type of bucket used, dirtiness of cows...). It is suggested that a close monitoring of herd management practices may allow the indirect control of milk quality parameters, thereby avoiding costly analyses of numerous smallholder milk deliveries.     

H7亚型禽流感病毒灭活疫苗的研制及其免疫效果研究

以H7N3亚型禽流感病毒接种鸡胚,收取鸡胚液为抗原研制禽流感病毒灭活疫苗,并对制苗抗原以及疫苗的物理性状、安全性、免疫效力、免疫剂量和保护期等进行了试验,结果表明,该灭活疫苗安全性好,对28日龄鸡的最佳免疫剂量为0.5 mL/只,抗体临界保护值为5log2,免疫后6周HI效价达到高峰值9.4log2,以后逐渐下降,第20周抗体仍能维持较高水平。此外,交叉免疫保护试验表明,同一亚型之间具有良好的免疫保护作用,而亚型间缺乏坚强的交叉保护作用。     

不同吸附剂对黄曲霉毒素B1吸附效果的研究

作者通过体外试验和动物饲养试验,研究3种吸附剂对黄曲霉毒素B₁（AFB₁）的吸附效果。3种吸附剂分别是吸附剂A（主成分为酵母培养物提取物）、吸附剂B（主成分为水合铝硅酸盐）、吸附剂C（为复合物,主成分为酵母培养物及水合铝硅酸盐）。体外试验研究pH为2.0、6.0、8.0的磷酸盐缓冲液（PBS溶液）、人工胃液和肠液环境下3种吸附剂对AFB1的吸附能力,比较pH 8.0条件下3种吸附剂对AFB1的结合速率。结果表明,各种条件下吸附剂B的吸附能力最强。pH 8.0条件下,吸附剂B在10 min内对AFB₁吸附率达到97.69%,且60 min内吸附率一直处在96.03%以上。吸附剂A和吸附剂C对AFB₁的作用效果较吸附剂B弱。动物饲养试验选择240只1日龄健康雄性AA肉仔鸡,随机分为8个处理,每个处理3个重复,每个重复10只鸡,饲养周期21 d。结果表明,与基础组相比较,AFB₁组（污染水平为98.8 μg/kg）肉仔鸡生长性能和肝脏功能发生显著变化,吸附剂A、B、C均能不同程度地缓解AFB₁对肉仔鸡生长性能和肝脏损伤方面的毒性作用,与吸附剂A、C相比,吸附剂B能更有效的防止肉仔鸡黄曲霉毒素B1中毒。结果提示,使用吸附剂B能很好的降低AFB₁对肉仔鸡的危害程度。     

复方球虫散对人工感染鸡球虫病治疗效果的临床试验

为科学、客观地评价复方球虫散对实验性鸡球虫病的防治效果,采用人工接种柔嫩艾美耳球虫孢子化卵囊的方法复制鸡球虫病,使用纯中药组方复方球虫散进行鸡球虫病的临床疗效试验,观察并计算复方球虫散对试验鸡的死亡率、相对增重率、病变值和卵囊值的影响,并求出复方球虫散的抗球虫指数(ACI).试验结果表明:复方球虫散按1.0%拌料混饲,对鸡球虫病有较好的治疗效果.     

南方典型水稻土长期试验下有机碳积累机制研究Ⅳ.颗粒有机质热裂解-气相-质谱法分子结构初步表征

采用热裂解-气相-质谱（Pyr-TMAH-GC/MS）技术对长期不同施肥处理下太湖地区黄泥土本体土壤及水稳性团聚体中颗粒有机碳（POC）的化学组分进行了研究。结果表明, POC的热裂解产物主要来源于脂肪族化合物和木质素类化合物。木质素类化合物主要以愈疮木基丙烷（G）和p-羟苯基（P）两种木质素单体为主,从而揭示黄泥土POC积累中草本植物（水稻、油菜的残茬和秸秆）的输入贡献。脂肪族化合物主要为C8-C30脂肪酸甲基酯（FAMEs）,且大多为偶数碳结构。施肥改变了各裂解产物在本体土壤和水稳性团聚体中的分布,从而使得不同施肥处理下各类化合物对POC稳定性的贡献出现了差异。化肥配施猪粪下木质素类化合物以及微生物源的脂肪族化合物均贡献于本体土壤POC的积累与稳定,而化肥配施秸秆下本体土壤POC的化学稳定性主要归因于高等植物源化合物的贡献,其次为微生物源脂肪族化合物。化肥配施有机肥下水稳性团聚体中较高的POC主要归因于植物源有机物质的分解贡献。本研究揭示了合理施肥下水稻土中有机碳的化学抗性组分在土壤有机碳积累中的促进作用,各组分的相对分布差异可指示有机碳积累的不同来源。     

栽培与野生黄花蒿中化学组分的FTIR表征及青蒿素含量比较分析

本研究运用FTIR技术,对栽培和野生黄花蒿不同部位化学成分的红外光谱特征进行指认,并比较分析两者不同部位青蒿素含量差异。结果显示：酰胺、芳香类物质均以栽培黄花蒿茎和叶片中多;可溶性多糖和糖苷类物质,栽培与野生黄花蒿茎中含量相近,但是,叶片中含量以栽培黄花蒿高;纤维素类物质,栽培茎少于野生茎,而两种黄花蒿叶片的纤维素含量相近。与青蒿素标准品比较,栽培和野生黄花蒿不同部位青蒿素含量有一定差异,其中栽培叶最高,其次是野生叶,栽培茎的含量最低。所以,运用FTIR技术可以快速判断栽培和野生型黄花蒿主要化学成分的差异,本研究对黄花蒿的引种驯化和良种选育工作有一定指导意义。     

Phosphorus limitation in a Ferralsol: Impact on microbial activity and cell internal P pools

Soil microorganisms are key regulators of the biogeochemical phosphorus (P) cycle. Microbial P limitation in highly weathered tropical soils has been reported, but whether it affects the cellular P content of indigenous soil microorganisms and its biochemical composition is unknown. We investigated the effect of microbial P limitation by measuring respiration, microbial growth, community composition and P content of microbial cells in a Ferralsol with low amounts of available P as affected by amendments with C substrates with ample nitrogen (CN) with and without extra phosphate (P). Microbial biomass and community composition were quantified by phospholipid fatty acid (PLFA) analyses. Cellular P content and P pools (PLFA, DNA and RNA per cell) were determined after extraction of microbial cells from soil by density gradient centrifugation. The apparent microbial growth rate during exponential increase in respiration rates in response to CNP addition was 0.072 h⁻¹, compared to 0.017 h⁻¹ for the CN amendment (no extra P added). This suggests that the microbial growth after a combined C and N addition was retarded by P limitation in the native soil (without added P). The net increase in microbial biomass, however, reached similar levels for both the CN and CNP treatment (measured at the point in time when respiration rates peaked). This outcome was unexpected since maximum respiration rates were about three times higher in the CNP compared to the CN treatment. Total P in extracted cells ranged from 2.1 to 8.9 fg P cell⁻¹ (microscopic counts), with a tendency for lower values for treatments without C amendments. Only 10-25% of the measured total P in extracted cells was accounted for by the measured RNA, DNA and PLFA. This low percentage could partly be due to underestimation of the RNA pool (degradation during extraction). PLFA analyses showed that substrate induced growth, regardless of P addition, led to a change in microbial community composition and was dominated by fungi. The extraction of microbial cells from soil by density gradient centrifugation, however, discriminates against fungi. Accordingly, the extracted cells were not fully representative for the entire soil microbiota regarding the community composition and metabolic state. Nevertheless, for the first time microbial cell P content and P pools are reported for microorganisms that actually grew in soil and not in chemostat or batch cultures.     

新型鸭呼肠孤病毒病灭活疫苗的制备及免疫原性分析

鸭出血性坏死性肝炎是新型鸭呼肠孤病毒引起的危害养鸭业的一种新传染病。为防制该病,本研究以NDRV JM85株为种毒研制成油佐剂灭活苗,并通过免疫血清学检测及攻毒保护试验评价疫苗效果。结果表明,该疫苗安全性好,免疫原性强,麻鸭二免后28d产生较高的中和抗体,并能维持较长时间。种番鸭免疫后的子代雏番鸭具有一定的母源抗体,能够抵抗强毒的感染,可用于防制鸭新型呼肠孤病毒病。