Clone of Chinese Jinan red-cross yellow cattle and evaluation of reproductive characteristics of cloned calf

Somatic cell clone technology is a viable approach to preserving endangered livestock and wildlife genetic resources. In the present research, somatic cell nuclear transfer （SCNT） was performed using granulose cells from the critical endangered Chinese red-cross yellow cattle as donor cells. A total of 211 oocytes were manipulated and 166 （79%） of them were successfully enucleated. 112 （67.4%） SCNT embryos were reconstructed, 94 （83%） of them cleaved, and 48 （43 %） of them developed to blastocyst stage. SCNT blastocysts were transferred to 6 Holstein recipients, and 2 （33%） of them were found to be pregnant. One of them maintained to term and delivered a calf, whereas another aborted. Effect of different fusion buffer （mannitol vs. Zimmerman fusion buffer） and different activation methods （calcium ionophore＋6-DMAP vs. cycloheximide＋CB） on fusion rate and development of SCNT embryos were investigated. The results indicated that： （i） on condition of two DC pulses of 2.5 kV/cm for 10 μs each, fusion rates were higher in mannitol solution than in Zimmerman fusion buffer （71% vs. 61%, respectively, p 〈 0.05）, but the blastocysts rates did not differ between two treatments （36 % vs. 39 %, p〉0.05 ）; （ii） There was no significant difference in development rates to the blastocyst stage for SCNT embryos activated by calcium ionophore＋6-DMAP or by cycloheximide＋CB （42% vs. 46%, respectively, p〉0.05）. Microsatellite DNA analysis examining 28 loci confirmed that the cloned calf was genetically identical to the donor Jinan red-cross yellow cattle and different from the recipient females. Growth and reproductive performance of cloned cow were evaluated, and there were no difference i cross-red n it between cloned and normal control Jinan yellow cattle. Furthermore, the cloned yellow cow has delivered a healthy yellow calf.     

利用微生物提高作物秸秆饲用价值的研究

研究了微生物(乳酸菌和酵母菌混合发酵物)发酵玉米秸秆对饲用价值和奶牛饲喂效果的影响。实验处理为用筛选的微生物制剂发酵纯秸秆粉、纯秸秆粉补充氮源(豆粕粉)和碳源(玉米粉),对照为清水发酵上述原料。结果表明,作物秸秆粉经微生物发酵后有机酸(以乳酸计)含量接种后24h内大幅度提高,之后持续缓慢增加,而清水发酵的对照则没有酸积累现象;与清水发酵对照和不发酵原料相比,微生物发酵处理纯秸秆粉的粗蛋白、粗脂肪和粗纤维变化无明显差异;但发酵原料中补充碳、氮源后,微生物发酵处理的粗脂肪、维生素B含量大幅度提高,粗纤维含量显著降低,粗蛋白含量变化不明显。奶牛试验表明,与清水发酵玉米秸秆相比,微生物发酵秸秆处理产奶量增加了17.0%,乳脂率增加了1.01%。     

CRISPR技术对发酵乳制品中嗜酸乳杆菌的检测应用

借助CRISPR-HOLMES系统,以市售酸奶作为检测对象,检测了其中的嗜酸乳菌含量.结果表明:CRISPR技术可作为一种有效直观的方法实现对发酵乳制品中嗜酸乳杆菌的定性检测.     

浅析乳制品质量管理发展瓶颈及建议

近些年来,乳制品安全事件屡次发生,不断引起消费者的恐慌,其质量与安全问题无疑成为制约乳品产业发展的重要瓶颈。本文就乳品质量安全各个环节上进行了初步的探讨,并在管理方面上提出了一些有针对性的建议。     

奶牛乳腺炎与P物质和肥大细胞的相关性研究

应用组织学、组织化学和免疫组织化学方法对奶牛不同病变时期乳腺不同部位的肥大细胞的数量、活力以及P物质表达水平的动态变化进行了研究.结果表明,乳腺炎乳腺组织中大量的炎性细胞浸染小叶间质、腺泡及腺上皮细胞间、腺泡腔内、乳导管及血管内壁与周围,并随着病程延长,乳腺不同部位的炎性细胞急剧增多,并呈上升趋势,与正常乳腺比较差异均有统计学意义（P〈0.01）,其中,乳基部（乳腺炎3个月）最高,其和乳体部与乳头部比较差异均有统计学意义（P〈0.01）;腺泡结构渐进紊乱,小叶内血管内膜突起出现裂隙;乳腺不同部位的黏膜肥大细胞及其脱颗粒变化和P物质的表达水平均与炎性细胞浸染变化相吻合,且P物质神经纤维与肥大细胞相关联.P物质和肥大细胞参与奶牛乳腺炎的病理进程.     

南阳黄牛CD14基因扩增及序列分析

根据GenBank发表的荷斯坦奶牛CD14基因的序列设计引物,通过PCR方法对南阳黄牛的CD14基因进行分段扩增并测序,拼接后得到包含CD14完整编码区以及5’端和3’端非编码区的2 969 bp的全序列。序列分析结果表明:南阳黄牛CD14基因开放阅读框全长966 bp,共编码321个氨基酸,碱基组成分别为A(18.4%)、T(18.4%)、C(32.9%)、G(30.2%),编码区与荷斯坦奶牛CD14基因相比发生了2个碱基突变,没有引起氨基酸的改变。在5’端和3’端存在较长的非编码区,与荷斯坦奶牛CD14基因相比发生了7个碱基突变。南阳黄牛的CD14基因与荷斯坦奶牛、水牛、绵羊、山羊、猪、猕猴、大猩猩、人、小鼠的同源性依次降低,分别为99.8%、98.2%、96.8%、92.8%、83.5%、79.8%、79.7%、79.5%、71.9%。进化树所得的聚类结果与传统的分类结果一致。通过蛋白质结构预测,发现南阳黄牛CD14没有跨膜结构域。     

P物质在临床型乳腺炎奶牛肝组织中的表达及意义

应用组织化学和免疫组织化学方法对正常与临床型乳腺炎奶牛肝组织中P物质的表达水平、炎性细胞以及肥大细胞的数量、活力、组化性质的变化进行了研究．结果表明，P物质在临床型乳腺炎奶牛肝组织的肝血窦、肝小叶间质、中央静脉、小叶闻动脉和静脉周围并常丰富，呈单根或多交错成网走行，表达增强．临床型乳腺炎奶牛肝组织的肥大细胞和炎性细胞也急剧增多，均极显著高于正常奶牛（P〈0．01），并与P物质的表达水平相吻合．同时，肝细胞索结构出现紊乱，肝小血管的内皮细胞出现脱落．由此表明，P物质参与临床型乳腺炎病理过程中所致肝组织损伤的病理进程．     

不同接种物对牛粪高温厌氧发酵的影响

研究了不同污泥培养的接种物对牛粪厌氧发酵启动时间、COD和BOD5降解情况、VFA及pH、产气量与产气速率的影响。结果表明:二沉池污泥培养的接种物厌氧细菌、产甲烷菌含量高,活性大,浓缩污泥培养的接种物次之,河床污泥培养的接种物各菌种数量及含量最少,且出现板结现象。接种物浓度一定条件下,用二沉池污泥培养的接种物接种,厌氧发酵体系启动速度快,COD、BOD5降解率高,产气量大且平稳。     

Chromsome aberrations in cattle raised on bracken fern pasture

Summary Thirteen cows maintained on natural bracken fern (Pteridium aquilinum) were analyzed cytogenetically. The frequency of structural chromosome aberrations detected in peripheral blood cells was significantly higher when compared to that detected in animals raised on pasture containing no bracken fern. We discuss the clastogenic action of fern and its synergistic action with infection by type 2 and 4 papilloma virus in the same animals.Acknowledgments. We are grateful to Dr F. J. Benesi, Dr J. L. Guerra and Dr I. L. Sinhorini for performing some of the clinical and pathological analyses; O. P. Ferraz, L. A. Tadeu Dias, L. F. Feitosa and A. M. N. Paiva for technical assistance; and to Dr N. H. C. Castro and Dr C. de Araujo Peres for critical and statistics review, respectively. Research was supported by CNPq FAPESP and CAPES.     

牛胚胎移植在山西的研究与应用

选择60头本地黄牛进行同期发情和胚胎移植研究，结果表明：CID—B和ODB处理组的同期发情率显著高于PMSG和PG的处理组（p〈0．01），60头受体牛中，黄体合格进行胚胎移植的共23头，移植率30．4％，产犊率26．1％，其中A，B级胚胎在移植受体中差异不显著（p〉0．05）。