细胞外高钙对鸡肾小管上皮细胞活力和NO产生的影响

为探讨一氧化氮（NO）在高钙致鸡痛风中的作用，利用已建立的鸡原代肾小管上皮细胞的体外研究模型，经不同浓度的钙进行处理．通过MTT比色法观察了高钙对细胞活性的影响；采用硝酸还原酶法测定了不同浓度高钙处理原代肾小管上皮细胞后培养上清液中亚硝酸根／硝酸根（NO2^-／NO3^0）的含量（NO的静态氧化形式）。结果表明，分别用4．0mmol／L（试验组Ⅰ），8．0mmol／L（试验组Ⅱ），12．0mmol／L（试验组Ⅲ），16．0mmol／L（试验组Ⅳ）Ca^2＋处理细胞，各时段组的细胞活性与对照组相比均显著降低（P〈0．01），且细胞外钙浓度越高，细胞活性降低越明显。高钙处理细胞24h后．各组培养液中NO的含量较对照组升高不显著；48h后，试验Ⅳ组的NO比对照组显著升高；72h后，各试验组与对照组相比NO的含量均显著升高。这些结果说明，细胞外高钙能够直接损害肾小管上皮细胞，而NO可能在肾小管上皮细胞的损害中起一定的作用。     

多种提取方法比较野生与栽培蒲公英绿原酸含量

目的:比较野生与栽培蒲公英绿原酸含量。方法:利用紫外分光光度法,通过超声波法、乙醇回流法、甲醇回流法提取,分别测定野生蒲公英和栽培四倍体蒲公英的绿原酸含量。结果:超声波提取法:栽培蒲公英绿原酸含量0.41%,野生蒲公英绿原酸含量0.25%;乙醇回流法:栽培蒲公英绿原酸含量0.33%,野生蒲公英绿原酸含量0.23%;甲醇回流法:栽培蒲公英绿原酸含量0.31%,野生蒲公英绿原酸含量0.19%。结论:栽培蒲公英中绿原酸含量较高。     

柠檬酸对三黄土鸡早期生产性能的影响

用海大香特1号三黄土鸡雏鸡进行饲养试验，对添加0．3％、0．5％、0．7％柠檬酸饲养的试验组和不添加柠檬酸饲养的对照组进行体增重、采食量、料肉比等生产性能的比较，试验结果表明：添加0．3％柠檬酸试验组的三黄土鸡早期体增重，显著高于对照组，同时也高于添加0．5％、0．7％柠檬酸的试验组；添加0．3％柠檬酸试验组的料重比、成活率也优于其他试验组。     

The Effect of Caffeic Acid on Zearalenone-induced Ovarian Granulosa Cell Apoptosis in Mice

Ovarian granulosa cells provide a special microenvironment for follicle formation and maturation through interaction with oocytes and their own secretion. A variety of harmful stimuli can cause granulosa cell apoptosis and metabolic disorders, reduce the quality of oocytes and have a negative impact on embryo formation. Zearalenone (ZEA) is a common cause of ovarian granulosa cells injury in the livestock industry, which is produced by mycotoxins, and lack of effective treatment drug. Therefore, in the current study zearalenone was used to induce ovarian granulosa cell injury and to explore the protective effect of caffeic acid on zearalenone-induced ovarian granulosa cell apoptosis in mice. Mouse ovarian granulosa cells were isolated by mechanical method, and indirect immunofluorescence was used to identify the isolated cells. MTT assay was used to determine the effect of caffeic acid on the activity of normal mouse ovarian granulosa cells.After granulosa cells were co-treated with caffeic acid (200, 100 and 50 μg·mL^-1) and ZEA for 24 hours, and control and ZEA group were set up at the same time, cell morphology and adherence were observed under a microscope. MTT was also used to detect cell viability. Caspase-3 mRNA expression level was detected by qRT-PCR. Cleaved-caspase-3 and cleaved-PARP protein expre-ssion levels were determined by Western blot. The results showed that positive FSHR staining appeared in cell cytoplasm of the test group, which confirmed that the isolated cells were mouse ovarian granulosa cells. The cell viability was above 90% which showed that caffeic acid had no toxic effect on granulosa cells. Compared with control group, ZEA group had smaller cell size, poor adherence, increased cell gap, and significant reduction in cell viability (P<0.001). Furthermore, the relative expression of caspase-3 mRNA, and cleaved-caspase-3 and cleaved-PARP protein level were significantly increased (P<0.001) compared with the control group. After caffeic acid treatment, cell gap was reduced, adherence was tight, cell viability was significantly increased (P<0.001). Caffeic acid significantly reduced zearalenone-induced increase in caspase-3 mRNA, and cleaved-caspase-3 and cleaved-PARP protein expression level (P<0.001). This study indicated that caffeic acid can restore granulosa cell viability by inhibiting ZEA-induced apoptosis.     

添加不同乳酸菌对燕麦低温青贮发酵的影响

为了分析前期筛选出较耐低温不同乳酸菌（Lactic acid bacteria,LAB）对燕麦青贮发酵的影响,本试验以'陇燕5号’燕麦为原料,设置对照（CK）、商用菌株SLI和较耐低温菌株OL77,OL54及OL122共5个处理,在15℃,10℃和5℃低温下自然发酵45 d后进行营养成分、发酵品质和微生物数量的测定。结果表明：乳酸菌添加及温度对燕麦青贮的营养成分、发酵品质、微生物数量均有极显著影响。随着温度从15℃降至5℃,CK的粗蛋白（Crude protein,CP）降低了18.92%,氨态氮（Ammonia nitrogen,NH₃-N）增加了58.47%;与SLI相比,耐低温菌株OL77在提高干物质（Dry matter,DM）和CP、降低NH₃-N水平方面的效果优于OL54和OL122;添加剂在各温度处理下均提高了燕麦青贮发酵品质,15℃下添加OL77后燕麦青贮的pH值较CK和SLI分别降低了8.94%和1.57%,乳酸分别增加了79.23%和29.41%,乳酸菌数量分别增加了50.24%和15.61%。3个耐低温菌株中,OL77总体表现最优,促进燕麦低温发酵的效果最好。     

杜泊绵羊与小尾寒羊杂交后代肌肉风味的研究

本研究旨在通过对肌肉氨基酸和脂肪酸的检测,探讨杜泊羊与小尾寒羊杂交对肌肉风味的影响,为选育优质肉羊品种提供理论依据。结果表明：从氨基酸总量来看,杜寒F1较小尾寒羊和杜泊羊分别提高30．06％和0．57％,杜寒F2较小尾寒羊和杜泊羊分别提高29：49％和0．13％;从主要脂肪酸含量来看,杜寒F1较小尾寒羊和杜泊羊分别降低0．29％和10．05％,杜寒F2较小尾寒羊和杜泊羊分别降低13．54％和22．01％;从挥发性脂肪酸来看,杜寒F1较小尾寒羊和杜泊羊分别降低2．93％和6．44％,杜寒F2较小尾寒羊和杜泊羊分别降低21．24％和24．09％。杂交后代杜寒F1和杜寒F2氨基酸含量有所提高,同时能够降低羊肉膻味。     

藏羊脑动脉系统结构特征与高原适应性研究

藏羊对严酷的高原低氧环境适应性很强,是高寒牧区最适宜发展的畜种之一,开展藏羊与低海拔绵羊脑血管形态的比较研究,可为探讨藏羊的高原适应性机理奠定基础.研究以高原藏羊—欧拉型藏羊和生活在低海拔地区的滩羊脑为试验材料,采用管道铸型腐蚀技术,运用比较解剖学方法对二者脑动脉系统的结构特性开展研究.比较发现,藏羊和滩羊脑动脉系统的大体解剖结构相同,但藏羊的大脑后交通动脉、上颌动脉的管径显著比滩羊粗,其它脑动脉管径平均值也略大;藏羊脑硬膜外异网显著长于滩羊;藏羊主要脑动脉中的侧支更发达,伸展较长,细小分支更丰富.藏羊有相对发达的脑动脉系统,利于向脑组织有效供血,可能是藏羊适应高原环境的结构特征之—.     

奶牛高产养殖技术要点分析

随着人民物质生活水平的不断提升,畜禽产品的需求量也在不断增大,奶牛产业作为畜牧业的重要组成部分,是农牧民增产、增收的重要途径。奶牛饲养过程中,泌乳量的多少直接影响奶牛养殖场（户）的经济效益,如何让奶牛充分发挥其泌乳性能一直是奶牛养殖过程中需要解决的问题。本文在阐述高产奶牛生产特点的基础上,从多个角度分析了奶牛高产养殖技术的要点,为奶牛养殖场（户）正确进行饲养和管理,充分发挥奶牛生产性能提供理论基础。     

Effects of amino nitrogen on fermentation parameters by mixed ruminal microbes when energy or nitrogen is limited

Ruminal microbes harvested from a ruminally fistulated cow were incubated in simple batch and semicontinuous cultures with NH₃‐N or amino‐N on nitrogen‐ or energy‐excess diets in quantity (HN and LN diets, respectively, consisting of timothy hay plus soybean meal, or corn grain), based on evaluation with the National Research Council and Cornell Net Carbohydrate and Protein System models. In a batch culture experiment, supplementation with amino‐N promoted digestion and fermentation in the course of incubation (4–24 h) on both diets, but these effects mostly disappeared when the diets were sufficiently digested (at 48 h). In a semicontinuous culture experiment using Rusitec, no effect of amino‐N was exhibited after sufficient fermentation and digestion, but significant promotion of digestion was shown in the course of incubation on the HN diet, while no such effect was detected on the LN diet. The microbial yield for 24 h did not show a significant difference between the N sources of either of the two diets. These results suggest that the stimulatory effects of amino‐N are diminished when the diets are sufficiently digested after a long retention and incubation, and also that the effectiveness of amino‐N does not require a quantitatively energy‐excess status.     

提高牛乳中共轭亚油酸含量的研究进展

共轭亚油酸已成为目前药物、食品及动物营养等研究领域的一个热点,其保健作用引起越来越多的关注和重视。作者阐述了现阶段提高牛乳中共轭亚油酸含量的各种方法和手段,为今后共轭亚油酸的深入研究作一参考。