苜蓿高效再生体系研究进展

作为牧草生物技术的一个重要组成部分,苜蓿Medicago sativa组织培养工作在国内外得到了大量开展.从苜蓿组织培养中外植体和培养基的选择、细胞生长调节物质的应用以及基因型的选择4个方面阐述了苜蓿高效再生体系研究现状,并对目前研究中存在的问题进行了归纳,提出了苜蓿再生体系研究的发展趋势.     

家蚕葡萄糖-甲醇-胆碱氧化还原酶家族基因BmGMCβ2的克隆及序列与表达分析

葡萄糖-甲醇-胆碱氧化还原酶(glucose-methanol-choline oxidoreductases,GMC)家族是昆虫体内一大类以黄素腺嘌呤二核苷酸(FAD)为辅酶的氧化还原酶类,家蚕基因组中含有43个GMC家族基因。以家蚕5龄幼虫cDNA为模板克隆到一个家蚕GMC家族基因,命名为BmGMCβ2(GenBank登录号:JQ965926)。该基因cDNA全长1 875 bp,编码624个氨基酸,预测蛋白质分子质量为69.3 kD,pI为6.21,定位于家蚕16号染色体的nscaf3058上,编码蛋白质含GMC家族共有的ADP-bindingβ-α-β折叠结构域。系统发育分析表明该基因是家蚕GMC家族β亚家族基因成员。RT-PCR检测家蚕不同发育时期和5龄第3天幼虫不同组织中BmGMCβ2基因mRNA转录水平,以5龄盛食期最高,并且主要在表皮、脂肪体和气管中转录表达;Westernblotting分析BmGMCβ2蛋白主要在5龄第3天幼虫的脂肪体中表达。将BmGMCβ2克隆到原核表达载体pET-28a(+)中,转化E.coli BL21表达菌株,IPTG诱导表达BmGMCβ2融合蛋白,通过His-亲和层析得到纯化的融合蛋白并制备多克隆抗体,为后续研究该蛋白在家蚕生长发育过程中的功能奠定了基础。     

Effect of different hand-milking techniques on milk production and teat treatment in Zebu dairy cattle

The aim of the study was to test three different hand-milking techniques (“pull down”, “thumb in”, and “full hand grip”) and their effects on milk production and teat treatment. This is important since milk production in many tropical areas still rely on hand-milking. The study was carried out at a peri-urban farm in the Bobo-Dioulasso area in Burkina Faso. Twelve indigenous Zebu cows in early lactation were used in the study. The sequences of the treatments (hand-milking techniques) and the milkers were balanced for carry-over effects between successive periods and days, respectively. The sequences were constructed by using special Latin squares. Yield and composition of saleable milk was not affected by milking technique but there were differences between the milkers in milk yield. There was also a significant interaction for saleable milk yield between milker and milking technique. Hemoglobin in milk was measured as an indicator of teat damage. The hemoglobin content was numerically higher in post-milking strip milk samples than in saleable milk. It was concluded that the amount of milk removed depends mainly on the milker and how well the milking technique works for the individual milker. No effect of milking technique was observed on teat treatment.     

Effects of stable dust on farm animals-a review

The relationship between air quality-its dust content-and respiratory diseases of animals in the food industry and otherwise in examined. The correlation between dust content and incidence of disease in farm animals is also discussed. Lesions caused either directly or indirectly by dusttransported microorganisms are reviewd. Effects of dust on animal performance are included.This review is an attempt to compile available information on the natural occurrence of stable dust and the possibilities for its measurement and control.     

Environmentally sustainable production of food,feed and fuel from natural resources in the tropics

Responding to the challenges posed by global warming, peak oil and biofuels will require a paradigm shift in the practice of agriculture and in the role of live stock within the farming system. Farming systems should aim at maximizing plant biomass production from locally available diversified resources, processing of the biomass on farm to provide food, feed and energy and recycling of all waste materials. The approach that is the subject of this paper is that the generation of electricity can be a by-product of food/feed production. The concept is the fractionation of biomass into inedible cell wall material that can be converted to an inflammable gas by gasification, the gas in turn being the source of fuel for internal combustion engines driving electrical generators. The cell contents and related structures such as tree leaves are used as human food or animal feed. As well as providing food and feed the model is highly appropriate for decentralized small scale production of electricity in rural areas. It also offers opportunities for sequestration of carbon in the form of biochar the solid residue remaining after gasification of the biomass.     

东北白鹅和籽鹅血液生化指标

为建立东北白鹅和籽鹅血液生化指标的正常参考值及其正常参考范围,探讨东北白鹅和籽鹅的各项血液生化指标之间的差异显著性,随机抽取(12±0.5)月龄健康、体质量为(4.2±0.2)kg的东北白鹅母鹅和(3.5±0.2)kg的籽鹅母鹅各65只,空腹12h后翅下静脉采血,离心分离血清,应用半自动生化分析仪及试剂盒对血清22项生化指标进行检测分析。结果表明:东北白鹅和籽鹅丙氨酸氨基转移酶(ALT/GPT)、天门冬氨酸氨基转移酶(AST/GOT)、谷氨酸酰基转移酶(GT)、胆碱脂酶(CHE)、乳酸脱氢酶(LDH-L)、葡萄糖(Glu)、高密度脂蛋白胆固醇(HDL-C)、总蛋白(TP)、白蛋白(Alb)、钙(Ca)、肌酐(Cre)、镁(Mg)等血清生化指标之间差异达到极显著水平(P<0.01);碱性磷酸酶(ALP)、总胆固醇(CHO)、无机磷(P)之间差异达到显著水平(P<0.05);a-羟丁酸脱氢酶(a-HBDH)、尿素氮(BuN)、甘油三脂(TG)、尿酸(UA)、总胆红素(T.Bili)、直接胆红素(D.Bili)、氯(Cl)之间无显著性差异(P>0.05)。本试验建立的东北白鹅和籽鹅血液生化指标的正常参考值及其正常参考范围,为今后鹅的相关研究提供了基础的科学数据和基本的理论依据。     

青藏高原放牧高寒草甸主要温室气体通量及其主控因素研究

在青藏高原高寒草地不同放牧强度区设4个试验样地,分别为原生草甸(NM)、轻度退化草甸(LM)、中度退化草甸(MM)和重度退化草甸(HM),监测草地温室气体通量。结果表明:不同放牧强度对草地温室气体通量影响显著,放牧活动对高寒草甸的影响首先表现在植被上,而土壤环境的变化比较迟滞。通过逐步回归分析和因子拆分得知,草甸甲烷通量影响较大的环境因素为土壤紧实度和有机质,分别能解释44.6%和28.4%的总变异,CO2通量影响较大的环境因素为紧实度和生物量,分别能解释36.1%和32.8%的总变异,氧化亚氮通量影响较大的环境要素为紧实度和有机质,分别能解释50.1%和22.9%的总变异,家畜的践踏作用使退化草地紧实度增加,进而引起温室气体通量的改变,高寒草甸退化演替发展到重度退化阶段时释放大量温室气体。     

First report of <Emphasis Type="Italic">Neospora caninum</Emphasis> infection in cattle in Sudan

A cross-sectional survey was conducted in Sudan to determine sero-prevalence and risk factors associated with Neospora caninum infection in non-vaccinated dairy herds and to assess importance of the disease. Blood samples were collected from a total of 262 animals from 25 herds. Sera were tested for antibodies against N. caninum using ELISA test. The prevalence rates of N. caninum antibodies in cattle were high both at herd level (44%) and at individual animal level (10.7%). Herd level infection rates were similar in Khartoum State (43.7%) and at Gazira States (44.4%). The overall prevalence rates were higher (16.1%) in Gazira State than in Khartoum State (9%) but with no significant variation. The sero-prevalence at individual animal level was significantly higher (p < 0.05) in animals with history of abortion (12.8%) than in apparently healthy animal (11.3%), animal with history of infertility (8.1%), or neonatal death of calves (4.3%). In addition, significantly higher (P < 0.05) sero-prevalence was observed in samples collected during the rainy season (6.87%) than winter (3.05%) or summer (0.76%). However, no significant differences in sero-prevalence due to locality, animal breed, sex, and age were observed (p > 0.05). This preliminary study reveals for the first time the existence of natural N. caninum infection in Sudan. Also, the findings of the present study indicated that this disease is highly prevalent in two major areas of dairy production in the country, and this calls for control strategy to be implemented.     

新牧1号苜蓿两个抗逆相关基因启动子的克隆及分析

采用实时荧光定量PCR分析了新牧1号苜蓿（Medicago varia Xinmu 1）MvNHX1和MvDREB1基因在盐胁迫下的表达情况。此外,根据已获得的MvDREB1和MvNHX1基因序列设计特异引物,并以新牧1号苜蓿的基因组DNA为模板,克隆得到了这两个基因的启动子。利用生物信息学方法,分析这两个基因启动子的类型和结构,结果表明,MvNHX1和MvDREB1基因的启动子序列中均含有通用启动元件和上游调控元件,如CAAT框、TATA框、光响应元件、低温响应元件等,但部分响应元件的种类和数量不同。通过对两个基因启动子的克隆、分析及比较为进一步研究这两个基因的表达调控机制奠定了基础。