苜蓿抗性愈伤组织诱导的初步研究

以硫酸二乙酯（DES)和紫外线(UV)对准格尔苜蓿愈伤组织进行诱变处理，筛选其半致死浓度和剂量。对诱变处理后的材料进行脯氨酸含量测定。结果表明，脯氨酸含量明显高于对照。筛选出具有抗性的苜蓿愈伤组织，为苜蓿抗性育种提供基础材料。     

苜蓿抗性变异细胞系的筛选

对准格尔苜蓿进行愈伤组织的诱导，以叠氮化钠和紫外线对苜蓿愈伤组织进行诱变处理，筛选其半致死浓度和剂量，并对诱变处理后的材料进行了脯氨酸含量测定，筛选出了具有抗性的苜蓿愈伤组织，为苜蓿的抗性育种提供基础材料。     

诱变苜蓿愈伤组织抗寒性研究

以3个苜蓿品种幼茎诱导产生的愈伤组织为材料,用叠氮化钠进行诱变处理,经-7℃低温筛选后,测定存活愈伤组织的可溶性糖含量、过氧化物酶活性以及脯氨酸含量等生理生化指标。结果表明,草原2号、准格尔、龙牧801三个苜蓿品种诱变处理后愈伤组织的抗寒性明显高于对照。     

苜蓿电生物效应的研究概况

为研究电场作用对苜蓿的积极影响和意义,从高压静电场处理苜蓿种子、高压静电场处理苜蓿植株以及高压静电场处理苜蓿愈伤组织3个方向系统地阐述了电场对苜蓿的电生物效应,以期充分认识电场对苜蓿种子发芽率、发芽势、幼苗含水量、幼苗生长发育、抗旱性、抗寒性和组织培养的出愈率等多种生理指标的影响,从而为深入研究苜蓿电生物效应的原理和作用机制提供一定的依据。     

紫花苜蓿不同栽培品种植株再生的研究

离体培养条件下对紫花苜蓿地方栽培品种--陇东苜蓿、和田苜蓿、准格尔苜蓿以及引进品种Rambler苜蓿植株不同部位的再生进行了研究,结果表明,不同的苜蓿品种、外植体、外源激素种类及其浓度等因素均影响着植株的再生.陇东苜蓿下胚轴愈伤组织出愈率和体细胞胚形成率最高可达91.04%和63.75%;和田苜蓿下胚轴愈伤组织出愈率最高可达92.05%,体细胞胚形成率最高为56.82%.这2个品种在紫花苜蓿的组织培养植株再生中是较理想的试验材料;紫花苜蓿下胚轴是理想的受体材料.苜蓿愈伤组织的诱导、体细胞胚的形成以2.0 mg/L 2,4-D处理2周为最佳;在2.0 mg/L 2,4-D 0.5～2.0 mg/L 6-BA的作用下,外植体产生愈伤组织以及进一步发育的趋势较强.对体细胞胚的发育和幼苗的形成则以2.0 mg/L 6-BA 0.5 mg/L NAA的激素组合进行处理.适宜的生根培养基为1/2 MS 1.0 mg/L IBA 1%蔗糖 0.7%琼脂.     

紫花苜蓿耐羟脯氨酸变异体的筛选及抗性研究

以紫花苜蓿Medicago sativa（敖汉苜蓿和龙牧801苜蓿）种子为材料,培养无菌幼苗。以无菌苗的茎段为外植体,诱导愈伤组织,并用叠氮化钠（NaN3）200 mg/L对愈伤组织进行诱变,以脯氨酸类似物L 羟脯氨酸（L Hyp）作为选择压力,通过在含半致死浓度的L Hyp（8 mmol/L）选择培养基及无L Hyp培养基上交替培养,分离出抗L Hyp的愈伤组织变异体。该变异体以高脯氨酸含量为特征,其脯氨酸含量分别比原型高2.84倍（敖汉）和3.17倍（龙牧801）,同时进一步测定其生理生化指标,发现变异体的可溶性糖含量是对照的1.56（敖汉）倍和1.76倍（龙牧801）,过氧化物酶（POD）活性与原型相比差异极显著。分别对2种苜蓿愈伤组织进行聚乙二醇（PEG）（敖汉）和低温（龙牧801）胁迫处理,结果显示,变异体具有更强的抗逆性（抗旱、抗寒）,能更好的适应恶劣（干旱、寒冷）的生长环境。     

苜蓿花药愈伤组织胚状体诱导因素的研究

以7个基因型的苜蓿花药愈伤组织为材料,进行了基因型、愈伤组织生长率、培养温度、培养基碳源等因素对苜蓿花药培养诱导胚状体影响的研究.结果表明:不同基因型苜蓿花药愈伤组织生长率、胚状体诱导率都存在显著性差异,两者的相关系数r=-0.326 1(P＜0.01),两者没有明显的相关性;低温处理可促进花药愈伤组织的分化,4℃低温...     

DES诱变与离体培养结合筛选柱花草抗寒突变体的研究

采用硫酸二乙酯(DES)在不同温度下对柱花草愈伤组织进行化学诱变处理,并结合添加有不同浓度L-羟脯氨酸的培养基进行离体筛选,将经两步法筛选后存活的愈伤组织诱导成小苗,采用1℃下光照培养8 d对小苗进行低温筛选,根据寒害程度将小苗分为4个等级。随机选取寒害程度最低的(一级伤害)小苗2株,分别切取其一部分茎段为外植体进行愈伤的诱导,其愈伤组织作为测定抗寒生理指标的材料。结果表明,DES的浓度与愈伤组织的存活率呈负相关,处理的温度与愈伤组织的存活率亦呈负相关,0.4%DES(10℃, 2 h)处理的愈伤组织经两步筛选后其存活率最高,为18.6‰,而对照为6.6‰。经过两步法筛选后存活的愈伤组织诱导的小苗在低温筛选后得到14株一级伤害苗,而对照植株中未获得一级伤害苗。抗寒生理指标的测试表明,一级伤害小苗的抗寒能力显著强于对照株。     

诱变处理苜蓿愈伤组织抗碱性的研究

以苜蓿Medicago sativa茎段为试验材料, 对其进行愈伤组织的诱导,采用紫外线和NaN3化学诱变处理苜蓿愈伤组织。对诱变处理和对照的愈伤组织先进行脯氨酸筛选,再进行NaHCO3和Na2CO3碱性胁迫,并进行过氧化物酶（POD）、可溶性糖和脯氨酸含量等抗碱性生理指标鉴定。结果表明:诱变处理3 种生理指标趋于一致,均比未经处理的高。紫外线辐射和NaN3化学诱变的方法均可用于提高苜蓿的抗碱性。其中紫外线诱变要比NaN3化学诱变更有利于提高苜蓿的抗碱性。     

紫花苜蓿花药愈伤组织和幼苗诱导技术的研究

在不同时期、不同花药低温预处理时间及热激处理、不同培养基、不同激素浓度组合、不同培养条件下对苜蓿花药进行了培养,结果表明：9月份较7月、8月份选取的花药愈伤组织诱导率高;花药低温预处理24～48h较72h处理对愈伤组织诱导的效果好,低温预处理与热激处理相结合比单用低温预处理其花药愈伤组织诱导率高;NB培养基对愈伤组织的诱导效果比B5培养基好,2,4-D浓度0.5～2.0mg/L、NAA浓度0.1～1.0mg/L、6-BA浓度0.5～1.0mg/L、KT浓度1.0～3.0mg/L都能诱导出愈伤组织,其最佳的浓度组合为NB＋2,4-D 0.5mg/L＋NAA 0.2mg/L＋ 6-BA 0.5 mg/L＋KT 3mg/L;暗培养结合光照培养较直接光照培养愈伤组织诱导率低,但绿苗率较高.     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.