水稻BWMK1互作基因的分离

为探明BWMK1介导的信号传导途径,采用酵母双杂交系统,构建水稻稻瘟病菌诱导后的cDNA文库,以BWMK1为诱饵,对文库进行筛选,通过验证、测序和基因编码分析,获得了7个BWMK1互作基因BWIP1～BWIP7,分别位于水稻基因组第12、2、3、10、6、4、5染色体上；7个互作基因中,除BWlP2和BWIP7未找到同...     

实时混合对抗蠕虫的建模和分析

传统的防病毒技术难以抵御蠕虫的传播，为此本文提出实时混合对抗技术，该技术在被对抗蠕虫感染的主机与易感染主机数量相等时转换对抗策略，并建立实时混合对抗蠕虫的传播模型.最后，通过仿真实验从对抗有效性、资源消耗和应对突发事件能力三个方面验证实时混合对抗技术的性能.理论分析和实验结果表明，实时混合对抗技术能更好地满足对抗有效性和低资源消耗要求，并能应对突发事件.     

成渝地区葡萄园营养状况初步研究与分析

在成渝地区具有代表性的葡萄园内进行了叶样和土样采集分析,结果表明:与标准值对比,大部分葡萄园内叶片中营养元素P与Mg含量水平较低,微量元素Mn与Fe含量水平则偏高；在大量使用有机肥的葡萄园内,土壤中速效性的营养元素N、P、K含量水平相对较高.     

密集烤房不同循环风机烘烤烟叶的色素降解及感官质量

采用三速和单速循环风机,研究密集烤房不同循环风机对烤烟色素及感官质量的影响.结果表明:采用三速循环风机烤后烟叶的叶绿素a、叶绿素b含量分别为5.10、167.74 μg/g,分别为单速循环风机的72.11％和93.30％;叶黄素、β-胡萝卜素、类胡萝卜素含量分别为0.84、155.56、156.40 μg/g,分别为单...     

Production,chemical composition,and fatty acid profile of milk from buffaloes fed with cupuaçu (Theobroma grandiflorum) cake and murumuru (Astrocaryum murumuru) cake in the Eastern Amazon

The objective was to evaluate the effect of concentrate supplementation using by-products of the Amazonian industry on milk production, milk composition, and milk fatty acid profile of dairy buffaloes. Twelve lactating buffaloes (544.5 ± 35.6 kg, 6.4 ± 2.2 years old, 59 ± 6 days in milk) were allotted in a pasture of Mombaça grass and managed under rotational grazing (4 days occupancy/28 days rest). A 3 × 3 Latin square was adopted, and each animal alternately received three supplementary treatments based on corn bran + soybean meal or cupuaçu cake or murumuru cake for 21 days per treatment. Murumuru cake increased the levels of lauric acid and myristic acid in the milk (p < 0.05). Murumuru cake reduced the unsaturated fatty acid contents in the milk compared with animals fed control diet or cupuaçu cake (24.27% vs. 25.24% vs. 25.08%). The n-6/n-3 ratio was 2.6, 1.97, and 2.0 in the control, cupuaçu, and murumuru groups, respectively. Based on this parameter, cakes made from cupuaçu as well as murumuru could be considered to be adequate for inclusion in dairy water buffalo feed. However, the murumuru cake addition requires some caution because its use induces the secretion of higher levels of lauric and myristic fatty acids that are related to human cardiovascular disease.     

奶牛常见繁殖疾病诊断与治疗

中国乳制品消费水平位于全球前三,奶牛养殖业在国内具有很大的发展潜力。随着奶牛养殖业的发展和扩大,繁殖疾病成为影响奶牛场经济效益的因素之一。繁殖疾病的发生和很多因素有关,包括营养、卫生等方面,体内激素不平衡也会诱发繁殖疾病的发生。本文对引起奶牛繁殖疾病的主要发病原因、临床症状、病理变化、临床诊断及治疗方法进行归纳总结,以期为繁殖疾病的诊断治疗提供理论基础。     

1株奶牛源松鼠葡萄球菌的分离鉴定及耐药性分析

为确定奶牛垫料中是否含有病原菌并深入了解垫料中优势生长菌的类型、耐药性及致病性等情况,本试验进行了细菌分离培养、革兰染色镜检、生化试验鉴定、16S rDNA序列分析及同源性比对、药敏试验、小鼠致病性试验。结果显示,分离菌在普通营养琼脂平板上形成圆形、表面光滑的白色菌落,血琼脂平板上形成黏稠、较大的白色菌落。革兰染色镜检结果显示,分离菌为革兰阳性,球型,呈葡萄串状排列,或单个散落。生化试验结果显示,分离菌对木糖、葡萄糖、麦芽糖、果糖、乳糖、硝酸盐还原等呈阳性反应,而蜜二糖、木糖醇、山梨醇、尿素、V-P反应等呈阴性反应。16S rDNA序列分析结果显示,扩增的16S rDNA序列长度为1 298 bp,与松鼠葡萄球菌的核苷酸同源性达99.85%~100%;系统进化树结果显示,分离菌与松鼠葡萄球菌处于同一分支。动物试验结果表明,分离菌株对试验小鼠有较强的致病性,以0.2 mL/只（7.9×10⁸ CFU/mL）菌液的剂量接种小鼠,在48 h内死亡率为60%（3/5）。药敏特性分析结果显示,分离菌株对复方新诺明、氨苄西林等7种药物敏感,对克林霉素、头孢噻肟和头孢呋辛中度敏感,对青霉素、红霉素和林可霉素耐药。本研究为奶牛源松鼠葡萄球菌的分离鉴定及防控提供了参考依据。     

Green tea polyphenols supplementation alters immunometabolism and oxidative stress in dairy cows with hyperketonemia

Peripartal cows often experience negative energy balance, and are therefore prone to suffering from metabolic diseases such as hyperketonemia, which causes financial losses in dairy farms. This study aimed to investigate the effect of green tea polyphenol (GTP) supplementation during the periparturient period on production performance, oxidative stress and immunometabolism in dairy cows with hyperketonemia. One hundred Holstein cows were assigned to GTP (0.2 g/kg DM; n = 50) or control (without GTP; n = 50) group based on body weight, previous milk yield, and parity on d 15 before expected parturition. Subsequently, 10 cows with hyperketonemia were selected from each group, according to blood β-hydroxybutyric acid (BHBA) concentration between 1.2 and 2.9 mmol/L from 2 to 3 d postpartum. All cows were fed a close-up diet and a lactation diet with or without GTP supply from 15 d prepartum until 30 d postpartum. Milk and blood samples were obtained from 20 cows selected with hyperketonemia on 10, 20, and 30 d postpartum. Compared with control cows, greater milk yield and lower somatic cell count were observed in GTP cows. The GTP group had lower concentrations of BHBA, free fatty acids, cholesterol, triglyceride, reactive oxygen species, malondialdehyde, and hydrogen peroxide, greater concentrations of glucose, lower activities of aspartate aminotransferase, alanine aminotransferase, and glutamyl transpeptidase, alongside greater activities of superoxide dismutase, glutathione peroxidase, and total antioxidant capacity. Additionally, GTP supplementation up-regulated concentrations of interleukin-6 and interleukin-10, but down-regulated concentrations of tumor necrosis factor-α, interleukin-1β, interleukin-2, interleukin-8, and interferon-γ in plasma. Greater concentrations of plasma immunoglobulin G were also detected in the GTP group. Overall, the data suggested that GTP supplementation from 15 d prepartum to 30 d postpartum improved the milk yield and health status in cows with hyperketonemia during early lactation.     

Effects of Supplemental Complex Water Soluble Vitamin on Production Performance,Blood Biochemical Parameters and Oxidation Resistance of Dairy Cows

The objective of the study was to investigate the effects of supplemental complex water soluble vitamins on production performance, blood biochemical parameters and oxidative resistance of dairy cows in spring and summer.The experiment was designed by 2×2 factorial randomized blocks design.Eighty healthy dairy cows with similar parity and body weight were randomly divided to four groups, with 7 days of adaptation and 70 d experimental phase.The dairy cows in group Ⅲ and Ⅳ were fed a basal diet supplemented with complex water soluble vitamins in spring.The dairy cows in group Ⅱ and Ⅳ were fed a basal diet supplemented with complex water soluble vitamins in summer.The results showed that the ADFI and daily milk yield of dairy cows receiving water soluble vitamin in spring were extremely significantly higher (P<0.01);The ADFI of dairy cows receiving water soluble vitamin was significantly higher in summer (P<0.05) and daily milk yield were extremely significantly higher (P<0.01);The butterfat rate was extremely significantly increased and SCC was extremely significantly decreased in spring and summer (P<0.01);Supplementation of water soluble vitamin was also significantly increased LYM (P<0.05).In summer, T-AOC, T-SOD were extremely significantly increased (P<0.01), and TP, CK, LDH, TP, HDL and ALB were extremely significantly decreased (P<0.01) by water soluble vitamin supplementation than that of control group.In conclusion, complex water soluble vitamins could increase the production performance and non-specific immune function, improve the oxidative resistance and relieved the heat stress of the dairy cows.     

Study on Fans Cooling of Dairy Cowshed with Free Stall in Northern Mountainous Region of Hebei in Summer

The present objective of the study was to investigate the effect of fans cooling on dairy cow in northern mountainous region of Hebei in summer.Two cowsheds with the same structure and feeding technics were used to investigate the effect of fans on indoor temperature and humidity, physiological parameters and milking performance of dairy cow.The results showed that the average ambient temperature in cowshed with fans was 1.5℃ lower than that of the control cowshed, and the average wind velocity was 0.49 m/s higher than that of the control cowshed, reaching to 0.66 m/s.Temperature-humidity index (THI) of cowshed with fans was significantly lower than that of the control shed during the period of fans running (P<0.05).Besides, the rectal temperature and respiration rate of dairy cows in cowshed with fans were significantly lower than of the control cowshed (P<0.05), and the milk yield per cow per day was 17.0% higher than that of the control cowshed (P<0.05), however, the milk fat, milk protein and milk sugar were no significant difference from the control (P>0.05).Overall, fans could decrease indoor environment, moderate heat stress and increase performance and health of dairy cows in northern mountainous region of Hebei.