甜菜碱对猪不同阶段脂肪和蛋白质代谢的影响

对断奶仔猪、生长猪和肥育猪分别饲喂添加甜菜碱800、1000、1750mg/kg的饲粮，分别进行为期36、62、40d的饲养试验，并进行屠宰取样和分析测定。结果表明甜菜碱使断奶仔猪、生长猪、肥育猪的日增重分别提高8.71%(P<0.05)、13.20%(P<0.01)、13.32%(P<0.01);胴体脂肪率分别降低12.97%(P<0.01)、19.62%(P<0.01)、12.49%(P<0.01)；瘦肉率分别提高4.08%(P<0.05)、7.15%(P<0.05)、3.31%(P<0.05);肝脏中游离肉碱含量分别增加8.98%(P<0.05)、21.36%(P<0.05)、30.18%(P<0.01);血清中生长激素(GH)水平分别增高46.15%(P<0.01)、102.11%(P<0.01)、58.33%(P<0.05)；胰岛素样生长因子-1(IGF-1)水平分别增高38.74%(P<0.05)、44.74%(P<0.01)、47.95%(P<0.01)。生长猪和肥育猪皮下脂肪组织中苹果酸脱氢酶(MDH)的活性分别上升13.60%(P<0.05)和14.59%(P<0.01)，断奶仔猪有提高趋势，但差异不显著(P>0.05)。     

蜱免疫球蛋白结合蛋白研究进展

蜱体内的免疫球蛋白结合蛋白（immunoglobulin binding protein，IGBP）主要存在于血淋巴和唾液腺中，可以与进入蜱血淋巴中的宿主免疫球蛋白（immunoglobulin，Ig）结合，从而避免宿主免疫球蛋白对蜱内部器官的损害。免疫球蛋白结合蛋白结构和功能的进一步阐明，可为抗蜱疫苗的研发提供新的思路。本文综述了免疫球蛋白结合蛋白的发现及其研究进展。     

Characterization of the goldfish fecal microflora by the fluorescent in situ hybridization method

ABSTRACT:   Bacterial populations in goldfish feces were characterized by the fluorescent in situ hybridization (FISH) method. A total of nine different group-specific rRNA-targeted oligonucleotide probes were used. Approximately half of the microbial cells (57.8 ± 16.7%) were detected with a probe EUB338 and found to be bacteria. The microbial cells in 33–35 of the 35 samples from five specimens strongly hybridized with probes ALF1b, BET42a and GAM42a, suggesting that goldfish intestinal bacteria are mainly composed of α, β and γ-subclasses of Proteobacteria. The fact that a probe AER66 reacted with 25.6 ± 14.2% of the total microbial cells in all 35 samples, demonstrated that genus Aeromonas was the dominant species in the goldfish intestines. Genus Bacteroides including Bacteroides type A detected with a probe BAC303 was observed in 15 of 35 samples while other taxonomic groups determined with HGC69a, CF39a and P72 were detected in 6–11 of 35 samples. These results strongly suggest that Bacteroides shows the greatest daily fluctuation and interindividual variation in the intestines of goldfish. Moreover, the FISH method was proven to be useful for rapid enumeration of taxonomic groups of fish intestinal bacteria.     

猪圆环病毒II型结构蛋白的二级结构及其B细胞抗原表位预测

本研究以猪圆环病毒(porcine circovirus,PCV)II型的基因组序列为材料,采用Garnier-Robson方法、Chou-Farplus方法和Karplus-Schulz方法预测了其结构蛋白的二级结构,用Kyte-Doolittle方法对结构蛋白的亲水性进行了分析,用Emini方法预测了结构蛋白的表面可能性,以Jameson-Wolf方法预测了蛋白的抗原指数。然后综合评价了PCV-2型结构蛋白的B细胞抗原表位。结果表明,PCV-2结构蛋白形成α螺旋结构的能力较差,但是该蛋白含有较多的β折叠和转角结构,因而该蛋白具有丰富的二级结构。分析结果还表明结构蛋白具有多处抗原指数较高的区段,其中羧基端含有潜在的B细胞优势抗原表位,因此其在免疫学中的地位也应当引起重视。本研究将为猪圆环病毒的反向疫苗学的研究提供一定的理论依据。     

家畜胚胎干细胞的分离培养和鉴定

家畜胚胎干细胞的分离培养和鉴定工作对于研究和利用家畜胚胎干细胞具有重大意义。本文对文献中报道的各种分离、培养和鉴定方法进行了综述 ,并介绍了几种主要家畜的胚胎干细胞在近十余年间的研究进展情况。     

5种禾本科牧草草产量及营养品质比较

2002年5月~9月在内蒙古西辽河平原水浇地条件下进行了不同刈割方式下5种禾本科牧草的草产量及营养品质的比较研究。结果表明,鲜草草产量健宝、苏波丹二次刈割高于一次刈割,甜格雷兹、润宝、大力士一次刈割高于二次刈割;各品种干草草产量均以一次刈割高于二次刈割;受粗蛋白质含量的影响,粗蛋白质产量健宝、苏波丹、大力士二次刈割高于一次刈割,甜格雷兹、润宝、一次刈割高于二次刈割,综合产量及品质认为,健宝、苏波丹以二次刈割青饲喂利用为宜,甜格雷兹、润宝以一次刈割青贮利用较佳。     

Transformation of Upland Cotton （Gossypium hirsutum L.） with gfp Gene as a Visual Marker

The green-fluorescent protein (gfp) gene was evaluated as a screening marker during cotton (Gossypium hirsutum L.) transforming and plant regeneration.High expression of GFP (green-fluorescent protein)...     

RT-PCR法快速鉴别新城疫强弱毒株的试验

通过对大量不同毒力NDV F基因核苷酸序列的分析，根据强弱毒株F0裂解位点的序列差异设计合成了三对引物，建立了快速诊断新城疫并能鉴别其强弱毒株的反转录-聚合酶链式反应(RT-PCR)方法，整个试验过程可在5h内完成。试验表明，该方法具有快速特异和操作简便的特点，不仅适用于对鸡胚毒的检测，而且适用于对病鸡组织匀浆液的检测，是新城疫鉴别诊断和流行病学调查的颇具潜力的分子诊断方法。     

Production and related variables in bovine leukaemia virus-infected cows

A newly developed milk dot blot test was used to detect anti-bovine leukaemia virus (BLV) antibody in milk samples from 2079 lactating adult cows from among 61 herds. The milk dot blot test was highly repeatable; the concordance rate, compared with the agar gel immunodiffusion test performed on serum, was 83.5%. All herds contained BLV-positive cows; the prevalence rate was 36%. BLV-positive cows tended to come from larger herds and were older and more often later in lactation. Fourteen production and related variables (herd size, age, days open, days in milk, milk somatic cell count, milk, fat, and protein produced in the current lactation, projected production of milk, fat, and protein, and breed class average deviations for milk, fat, and protein) were compared between BLV-positive and BLV-negative cows. Although somatic cell count, milk produced, and projected production of milk and protein were related significantly to BLV status using simple tests of association, once the variables herd size, age and days in milk were controlled, these differences were removed. Further analyses using logistic (outcome: individual cow BLV status) and least-squares regression (outcome:herd proportion of BLV-positive cows) failed to show an association between any of the measured production or related variables and BLV-positivity. We concluded that the effect of BLV on production and related variables in dairy cows was below the sensitivity of our analytical techniques or was non-existent.Abbreviations ABCA herd average breed class average for milk, fat, and protein production - AVGAGE average age of the herd - ADIM herd average for days in milk - AGID agar gel immunodiffusion - AVGSCC herd average milk somatic cell count - BCA breed class average, a milk, fat and protein production index calculated by comparing a cow's actual 305-day lactation production to the corresponding BCA standard for the same breed, age, and month of calving - BLV bovine leukaemia virus - CALVINT calving interval - COWAGE cow age - DBCA breed class average deviation for milk, fat, and protein production, the difference between an individual cow's BCA and the herd average - DIM days in milk - HS herd size corresponding to the number of lactating cows in a herd - LACT actual amount of milk, fat, and protein produced in a cow's lactation - ODHIC Ontario Dairy Herd Improvement Corporation - PCTPOS percentage of herd that is BLV-positive - PROJ projected 305-day production for milk, fat, and protein by fitting to a standard lactation curve adjusted for days in milk and age at calving - RHBCA rolling herd average for breed class average for milk, fat, and protein production, the average for all cows that completed a lactation (cows must have completed a 305-day lactation) during the previous 12 months - SCC milk somatic cell count