三聚氰胺的毒理学研究进展

三聚氰胺(MA)化学性质稳定,在体内代谢不活泼,能以原体或同系物形式从尿液排出体外,在F344大鼠血浆中的半衰期为2.7h,在肾脏的清除率为2.5mL/min;MA对小鼠的半数致死量(LD50)为4550mg/(kg.bw),在国际化学物质急性毒性分级中属低毒性物质,接近微毒;MA对家兔、豚鼠和人眼无刺激作用;与三聚氰酸同时存在时毒性增加,毒性作用的靶器官为膀胱和肾脏;MA致癌性研究文献较少,结果也不一致,国际癌症研究中心认为MA对动物有致癌的可能性,但没有证据表明对人类有致癌作用。目前的研究认为,MA对环境和人的潜在危险性较小。对国内外关于三聚氰胺毒性的研究概况进行了总结,并综述了MA的污染及代谢、毒性和检测方法。     

苹果汁发酵乳饮料的研制

以苹果汁和牛奶为原料,以pH值和感官评分为指标,通过单因素和正交试验,确定苹果汁发酵乳的最优配方及工艺参数。产品的最佳配比:牛奶添加量55%、苹果汁添加量12%、蔗糖添加量5.5%。最佳发酵工艺条件:乳酸菌接种量3.0%、发酵时间5.0h、温度40℃。     

草地生态系统健康研究述评

阐述了草地生态系统健康的研究进展、存在问题和发展趋势,重点介绍了评价的指标体系和方法,包括结构功能指标体系法、综合指标体系及10多种方法的特点和适用情况.同时对于指标的筛选、权重的确定、标准的划分等难重点问题给出了建议.提出了用多种方法来评价同一研究对象来进行比较和矫正的观点,并强调形成集自然、经济、社会、人类健康为一...     

新型广谱杀虫药沙罗拉纳在国外伴侣动物体外寄生虫防治中的应用

沙罗拉纳(sarolaner)属异恶唑啉类化合物,是一种新型广谱杀虫药.沙罗拉纳已被证实通过特异性阻断昆虫γ-氨基丁酸受体和谷氨酸门控氯离子通道而显示出抗寄生虫活性.本文综述了近年来沙罗拉纳在国外伴侣动物体外寄生虫防治中的开发及临床应用情况,旨在为该药的深入研究和国内开发应用提供参考.近年来,该药主要用于犬猫等伴侣动物...     

国外生猪育种体系简析及对我国生猪育种的几点思考

选择是生猪育种的核心,而准确地选择和选种依赖于完善和成熟的育种体系。国际养猪发达国家(国际育种企业)对育种体系不断完善,长期进行生长、繁殖和肉品质等各类性状的表型测定,运用多场联合评估和基因组选择等方法不断提高遗传评估的准确性,不断挖掘新的育种性状,并进行测定、评估和选育,实现了种猪群体持续的遗传改良和综合性能的不断提升。本文对欧美发达国家(国际育种企业)的生猪育种技术体系进行了综述,以期为我国的生猪育种工作提供参考,并促进我国生猪种业的创新发展。     

44个紫花苜蓿品种的酸铝适应性与耐受性评价

为了解紫花苜蓿在贵州地区的适应性及耐酸铝胁迫机理,以44份紫花苜蓿品种为研究对象,研究紫花苜蓿处于酸铝胁迫下的生理变化,并揭示其生理变化与耐酸铝胁迫间的关系。利用基因与环境互作模型对两个地点1年的紫花苜蓿进行产量分析,筛选出阿尔冈金、新疆大叶苜蓿、Trifecta、Vernal和中牧1号苜蓿5个耐酸铝强适应品种。利用敏感型UC-1465和耐受型阿尔冈金进行酸铝胁迫试验。结果表明：相同处理下,耐受型紫花苜蓿的电导率、相对铝含量、死亡率显著低于敏感型;紫花苜蓿对酸铝胁迫的响应主要通过柠檬酸、苹果酸、乙酸、酒石酸、反丁烯二酸和草酸的显著（P<0.05）增加来体现,其中苹果酸的合成和分泌增多可能是其耐酸铝胁迫的重要原因。     

SMALL INTESTINAL EMPTYING TIME IN NORMAL BEAGLE DOGS

Gastric emptying time and small intestinal transit time in dogs are frequently discussed. However, it is often of interest to the radiologist to know what normal small intestinal emptying times should be. A total of 15 upper gastrointestinal studies was performed on five internal parasite-free, normal, standard Beagle dogs with three studies on each dog, 6 days apart. The ages and weights of the dogs ranged from 2–8 years and from 12.4–13.7 kg, respectively. Following 24-hour fasting, a dose of 10 ml/kg bw of 60% wt/vol barium sulfate suspension was administered through a stomach tube. Then, sequential radiographs were made at 30-minute intervals until the entire contrast medium column was in the colon and cecum. The mean, standard deviation, and range of gastric emptying time, small intestinal transit time, and small intestinal emptying time were 76 ± 16.7 (30–120), 73 ± 16.4 (30–120), and 214 ± 25.1 (180–300) minutes, respectively. This study offers the possibility that small intestinal emptying time may be used to further evaluate patients with suspected small intestinal partial obstruction, pseudo-obstruction, ischemia, or lymphangiectasia.     

绍兴鸭的研究现状

绍兴鸭是我国蛋用型鸭的高产品种。本文综述了绍兴鸭的选育、生长发育规律、生理生化特性、营养代谢、内分泌特点及产蛋性能。     

Genetic evaluation using random regression models with different covariance functions for test‐day milk yield in an admixture population of Thailand goats

The objectives of this study were to compare covariance functions (CF) and estimate the heritability of milk yield from test‐day records among exotic (Saanen, Anglo‐Nubian, Toggenburg and Alpine) and crossbred goats (Thai native and exotic breed), using a random regression model. A total of 1472 records of test‐day milk yield were used, collected from 112 does between 2003 and 2006. CF of the study were Wilmink function, second‐ and third‐order Legendre polynomials, and linear splines 4 knots located at 5, 25, 90 and 155 days in milk (SP25–90) and 5, 35, 95 and 155 of days in milk (SP35–95). Variance components were estimated by restricted maximum likelihood method (REML). Goodness of fit, Akaike information criterion (AIC), percentage of squared bias (PSB), mean square error (MSE), and empirical correlation (RHO) between the observed and predicted values were used to compare models. The results showed that CF had an impact on (co)variance estimation in random regression models (RRM). The RRM with splines 4 knots located at 5, 25, 90 and 155 of days in milk had the lowest AIC, PSB and MSE, and the highest RHO. The heritability estimated throughout lactation obtained with this model ranged from 0.13 to 0.23.     

欧盟屠宰检疫检验规则研究

作者对欧盟有关畜禽屠宰检验检疫法规指令、英国实施屠宰检疫的具体做法进行的研究梳理,旨在为我国制定实施相关屠宰检疫检验法规制度,开展屠宰行业管理提供借鉴和参考。