北京黑白花奶牛

北京黑白花奶牛是“中国黑白花奶牛”的一个主要组成部分,是解放以来,全市奶牛战线广大职工和科技人员在党的领导下,经过二十多年的共同努力培育成的一个奶牛品种群。目前,不仅牛群数量有了很大发展,由建国初期的1,500头增长到现在的16,000头,同时支援了兄弟省市2万多头;而且牛群质量也有了显著提高。到1972年,平均每头奶牛的年产奶量已超过5,300公斤,比解放初期的3,500公斤提高51.4％。1974年和1976年两次列入国家良种登记的3,365头奶牛,平均每头305天的产奶量为5,662公斤(按照国际标准折成含脂率4％的标准乳计算,下同),与西德乳业研究中心1973年报道的资料相比较,仅低于美国的6,830公斤(11.1万头平均)和瑞典的5,704公斤     

奶牛人工繁殖双胎

在大型哺乳动物的生育繁殖里,一般只怀一仔畜。在各种牛里,双胎频率幅度一般都在0.44％—8.84％。全苏列宁农业科学院畜牧业科学研究所Н.И.谢尔盖叶夫进行的实验,是以测定用胚胎移植的方法获取双胎可能性为目的的。因为奶牛的子宫具有两个角(左角和右角),可以把受了精的两个胚胎或一个移植到自由角里去。在受精以后第七天,采用非外科方法将在其它个体受精时获得的材料移植给受体奶牛。在最适宜的条     

云南省奶牛胚胎移植获得成功

胚胎移植技术对充分发掘和利用良种母畜的生产潜力,以加速良种的推广,具有重要的现实意义。现在,在奶牛和肉牛等家畜的改良和发展工作中,这一技术已在世界范围内广泛开发应用之中。我国目前已有不少省市正在展开这一工作。我们基于奶牛胚胎移植技术在云南省的开发应用和奶牛胚胎性别鉴别与性别控制研究的需要,于1988年5月份开展了奶牛的胚胎移植工作。现将结果报告如下。     

奶牛模拟妊娠产奶

我场5—956号处女牛,逾龄不发情,有近亲交配的缺陷:阴道实质性闭锁,子宫颈、子宫体发育不良,左侧子宫角及卵巢退化,实际上巳失去作奶牛饲养的价值。但考虑到该牛血统和体型发育较好,在领导大力支持和技术员、挤奶员的密切配合下,大胆进行人工刺激产奶试验,先用复方己酸孕酮注射两次,15天后开始出奶,前3天内象初奶,以后转入正常。305天产奶3,133公斤,奶比重为1.029。已送交奶库上市供     

云南省奶牛胚胎移植试验

实验用12头黑白花奶牛（3-9岁）,PGF[2α]作同步发情处理后,周期第10-12天,总剂量36 mg的FSH-P按递减方式每日肌肉注射2次,间隔12小时,共注射4天,在第3天加注PGF[2α]35 mg,进行超数排卵处理。12头供体牛共得胚135枚,可用胚数118枚,为总胚数的87.47%。平均每头得胚11.25枚。胚胎分别移植给20头同步发情处理的黑白花奶牛和20头黄牛受体（有3头为自然发情）,每头移植1枚胚胎。结果,奶牛受孕率为35%（受孕7头,产犊7头）;黄牛受孕率为40%（受孕8头,流产2头,产犊6头）。奶牛和黄牛总受孕率为37.5%。     

浅谈奶牛养殖的措施

牛奶自古以来都是人们生活中不可缺少的营养品,其中富含的大量蛋白质、氨基酸以及其他微量有机物,对人们的生长发育具有重要的促进作用。随着经济的发展和社会的进步,人们对于牛奶的需求量也在日益增多,奶牛养殖场的面积也在不断的扩大。奶牛养殖也在蓬勃发展的同时也给环境带来了巨大的压力。面对当前严峻的环境形势,对于奶牛的养殖必须兼顾经济利益和环境保护两个方面。     

“药”用奶牛

安全、廉价、环保、高效地生产任何一种天然存在或人工设计的营养、药用蛋白质,一直是科学家梦寐以求的一件事。近年来,生物技术领域的革命性突破使得这一梦想越来越接近现实……     

奶牛农场氮素平衡研究进展

规模化、集约化奶牛农场载畜率很高,通常没有配备足够的土地消纳粪污和规范的粪污处理系统,以致氮素排放量超过单位面积土地的环境承载力.奶牛农场是农业源氮素主要排放源之一,国外学者很早就关注了奶牛农场氮素平衡问题.奶牛农场氮素流动和平衡是研究奶牛农场氮素循环和氮素管理的基础,也是环境法律法规政策制定的依据;而氮素盈余和氮素利用率是评价奶牛农场氮素流动和平衡时使用最广泛的指标.本文基于农场尺度简述了氮素平衡的概念和农场内氮素流动,比较了氮素盈余和氮素利用率的使用范围,分析了影响氮素平衡的因素,综述了减少奶牛农场氮素排放的有效策略,以期为中国奶牛农场氮素管理提供参考和借鉴.     

泌乳期奶牛乳腺基因表达谱研究

从青春期到泌乳期以至干乳期,奶牛乳腺经历复杂的生物学功能和代谢水平的变化.通过基因芯片分析奶牛乳腺的基因表达谱,通过泌乳旺盛的泌乳期与不泌乳的青春期和干乳期相比较,共筛选出122个差异表达的基因,其中包括79个泌乳期上调基因和43个泌乳期下调基因.GO分析表明,在泌乳期奶牛乳腺中上调的基因主要与物质转运、生物合成、信号转导、催化活性、免疫防御、细胞凋亡以及促进发育相关.这些数据提示了奶牛乳腺泌乳期所发生的分子事件.     

奶牛瘤胃微生物研究进展和趋势

近年来在奶牛试验中,对瘤胃微生物的研究引起了人们越来越多的兴趣。这些研究的目的多是将微生物组成变化与日粮组成、宿主生产性能(如饲料效率,产奶量,乳脂等)、健康(如瘤胃酸中毒和亚急性酸中毒)以及环境(如甲烷排放)联系起来,另外还有一些研究则强调了微生物在多种反刍动物瘤胃发育中的作用。关于奶牛瘤胃微生物的大部分发现都是基于扩增子测序,可以揭示瘤胃微生物的分类组成,以及在不同处理条件下瘤胃菌群的变化。尽管新兴的宏基因组学和宏转录组学能够深入探索瘤胃微生物的功能,但在数据分析和解释方面也带来了更多的挑战,如目前大多数论文都严重依赖于相关性和推测分析。综述了奶牛瘤胃微生物研究的进展和局限,包括瘤胃微生物与产奶效率、甲烷排放以及瘤胃发育的关系,以及奶牛瘤胃微生物未来的研究趋势。     

毛冠鹿ZFY、ZFX基因片段的克隆与性别鉴定

根据人和鼠性别分化相关的ZFY、ZFX基因序列设计引物,以雌雄毛冠鹿的基因组DNA为模板进行PCR扩增,将扩增产物克隆到pMD18T上,获得ZFY、ZFX重组克隆,并测定了ZFY、ZFX基因片段的序列,序列比较显示两者同源性达 91%,仅在少数位点有差异,以此确定AvaⅡ为ZFX上特异酶切位点,通过PCR扩增和AvaⅡ特异酶切对毛冠鹿性别进行鉴定。 Abstract: According to the human sex differentiation related ZFY and ZFX genes, a pair of primers were designed , and fragments were amplified from the genomic DNA of male or female tufted deer. Subsequently the amplified fragments were cloned into the vector pMD18T and were sequenced. It is found that the sequences of ZFY gene and ZFX gene have 91% homology. Based on the different nucleotides, restriction site of AvaⅡ was found to be specific to ZFX gene. The results show that the combination of PCR with AvaⅡ digestion is a simple and sensitive way to identify the tufted deer sex.     

Identification of sex in Cetaceans by multiplexing with three ZFX and ZFY specific primers

We sequenced 540 nucleotides of the last exon in the ZFY/ZFX gene in two males and two females for eight cetacean species; four odontocetes (toothed whales) and four mysticetes (baleen whales). Based upon the obtained nucleotide sequences, we designed two sets of oligonucleotide primers for specific amplification of the ZFX and the ZFY sequence in odontocetes and mysticetes, respectively. Each primer set consisted of three oligonucleotides; one forward-orientated primer, which anneals to the ZFY as well as the ZFX sequence, and two reverse-orientated primers that anneal to either the ZFX or the ZFY sequence. The resulting two amplification products (specific for the ZFY and ZFX sequences) can be distinguished by gel-electrophoresis through 2% NuSieve™. The accuracy of the technique was tested by determination of gender in 214 individuals of known sex. Finally we applied the technique to determine the sex of 3570 cetacean specimens; 2284 humpback whales, 315 fin whales, 37 blue whales, 7 minke whales, as well as 592 belugas, 335 narwhals and 25 harbour porpoises.     

A rapid sex-identification test for the forest musk deer (Moschus berezovskii) based on the ZFX/ZFY gene

We describe a rapid sex-identification method for the forest musk deer (Moschus berezovskii) using PCR based on zinc-finger protein-encoding genes (ZFX/ZFY) located on the X and Y chromosomes. Fragments of the ZFX and ZFY genes were amplified and sequenced. The ZFX and ZFY fragments were identical in length and 94% similar in nucleotide sequence. Specific primers for forest musk deer sex identification were designed on the basis of sequence differences between ZFX and ZFY. All the primers were multiplexed in single-tube PCR. Both male and female forest musk deer showed amplification bands of 447 bp and 212 bp separated in agarose gels. A sex-specific 278-bp band was amplified only from males. These results show that testing by PCR for the presence of the 278-bp sequence is a rapid and reliable method for sex identification.     

牦牛与其他物种ZFX/ZFY基因片段间的进化关系

利用PCR扩增、克隆和序列分析法对牦牛ZFX/ZFY基因第11外显子部分片段进行了研究,并同来自于NCBI GenBank中人、猩猩、普通牛等9个物种的ZFX/ZFY基因核苷酸及其氨基酸序列进行了进化分析.结果表明,牦牛ZFX、ZFY基因间核苷酸序列同源性为94.1%,显示同一物种同源基因ZFX/ZFY间存在变异;比较的10个物种间ZFX基因核苷酸序列同源性为87.7%、ZFY基因为81.7%,相应ZFX、ZFY氨基酸同源性分别为96.6%、91.0%,ZFY基因的变异性大于ZFX基因,显示X染色体与Y染色体可能是独立进化.     

PCR-CTPP: a rapid and reliable genotyping technique based on ZFX/ZFY alleles for sex identification of tiger (<Emphasis Type="Italic">Panthera tigris</Emphasis>) and four other endangered felids

An inexpensive, time-saving and reliable method, polymerase chain reaction with confronting two-pair primers (PCR-CTPP), was developed for sex identification in tiger (Panthera tigris) based on zinc finger alleles (ZFX/ZFY). A site of “C/G” transversion representing fixed differences that discriminated between ZFX and ZFY exons among felids was identified for primers designing. This primer set was successfully tested on samples including blood, shed hairs, dried skin, and stool which contained potential contamination caused by prey DNA. Cross species tests shown that this primer set was also useful for sex identification in four other endangered felids.     

Zinc‐finger intron 7: a new locus for sex identification of giant panda (Ailuropoda melanoleuca)

We developed a single‐reaction test for identifying the sex of giant panda (Ailuropoda melanoleuca) targeted to co‐amplify homologous fragments with size polymorphism that located at zinc‐finger (ZF) intron 7 by using one pair of primers. This assay produced one sex‐specific fragment in females (XX genotypes) whereas two fragments were produced in males (XY genotypes). Indels (insertion/deletion) in intron 7 of Y‐linked allele provide a significant discrimination between ZFX and ZFY, thus the amplification products can be simply distinguished by agarose gel electrophoresis, exhibiting sex‐specific banding patterns (female, 354 bp; male, 354 bp, 135 bp). The new primer set was successfully tested on known‐sex giant pandas by using template DNA extracted from both blood and fecal samples. Cross‐species test was also performed, revealing that this assay could be applied to other Ursidae species. Zoo Biol 29:526–531, 2010. © 2009 Wiley‐Liss, Inc.     

Ovine-specific Y-chromosome RAPD–SCAR marker for embryo sexing

An accurate, sensitive, and quick (approximately 3 h) method for determining the sex of ovine embryos was developed using polymerase chain reaction (PCR) primers derived from an ovine-specific Y-chromosome random amplified polymorphic DNA marker ( UcdO43 ). The accuracy and sensitivity of the assay were first tested using genomic DNA from 10 males and 10 females of five different sheep breeds, and then tested using serial dilutions of male-in-female DNA. The assay was 100% accurate in confirming the sex of the individuals and the ovine male-specific fragment was detected in dilutions containing as little as 10 pg of male DNA in 50 ng of female DNA. The assay was also confirmed to be specific for the ovine Y-chromosome as bovine, caprine, porcine, murine, and human DNA did not amplify. The ovine embryo sexing method is a duplex PCR system that also includes ZFY/ZFX primers. ZFY/ZFX provide an internal positive control for amplification as well as a means to confirm the results obtained with the UcdO43 primers. All embryo sexing results (36/36) from our method were in agreement with the ZFY/ZFX assay results. However, while our method requires an internal control to detect PCR failure, it has the advantages of not requiring nested PCR or restriction endonuclease digestion of the PCR product, and concerns about cross-species contamination are eliminated.     

Cloning and sequencing of buffalo male-specific repetitive DNA: sexing of in-vitro developed buffalo embryos using multiplex and nested polymerase chain reaction

Buffalo Y-chromosome specific repetitive DNA (BuRY.I) was cloned and sequenced in order to develop a sensitive method for sexing of buffalo preimplantation stage embryos using polymerase chain reaction (PCR). A highly sensitive and reliable sex determination assay using a primary (BRY.I), nested (BuRYN.I) and multiplex (BuRYN.I, ZFX/ZFY) PCR was developed. The BRY.I and BuRYN.I primers are targeted to amplify Y-specific sequences, while the ZFX/ZFY loci was amplified to serve as a positive control for both male and female samples. Accuracy of the sex determination assay was initially verified with genomic DNA obtained from blood of known gender. Further sensitivity and reproducibility of the assay was examined using DNA obtained from 1 or 2 blastomeres to demi embryos. Altogether, 80 IVF-derived embryos ranging from the 2 to 4 cell to the blastocyst stage were used for sex determination. Definite and clear signals following PCR amplification were obtained from all embryo samples. Accuracy of assays was determined by comparing results from a single cell with those of blastocyst stage embryos, thereby indicating that 1 or 2 blastomeres from a preimplantation buffalo embryo is sufficient for sex determination by PCR. No misidentification was observed within the embryo samples using nested (BuRY.I), primary (BRY.I) and multiplex (BuRYN.I; ZFX/ZFY) PCR, suggesting that this technique is a highly reliable method for sexing buffalo embryos.     

PCR-sexing of bovine embryos: a simplified protocol

To make bovine embryo sexing under farm conditions more feasible we developed a simplified protocol utilizing manual biopsy and detection of the Y chromosome directly from polymerase chain reaction (PCR) reaction tubes. Twenty-four embryos (morulae and blastocysts) were biopsied manually into 2 to 4 samples. One sample of each original embryo was diagnosed for sex, based on restriction fragment length polymorphism of PCR-amplified DNA of the ZFX/ZFY locus. The remaining 44 samples were diagnosed using the tube detection assay. In this assay the biopsies were pipetted into 0.5 -ml reaction tubes containing lysis mixture, incubated 10 to 60 min at 37 degrees C and inactivated 10 min at 98 degrees C. Then the PCR mixture was added containing buffer, DNA polymerase, ethidium bromide and primers designed to amplify the highly repeated btDYZ-1 region of the bovine Y chromosome. After 50 cycles of PCR, the reaction tubes were examined under UV illumination for pink fluorescence indicating the presence of Y-chromosomal DNA. All sexing results from the replicates were in agreement with the ZFX/ZFY assay, with 12 of the original embryos diagnosed as females and 12 as males. We conclude that highly efficient and accurate PCR-sexing of embryos can be accomplished without the use of micromanipulators, control primers and electrophoresis. The 2 reaction mixtures needed for sex diagnosis can be stored at -20 degrees C and -196 degrees C, respectively. The tube detection assay minimizes the risk of carryover contamination by previously amplified products as there is no need to open the tubes following PCR.     

Sex determination in spotted hyena (Crocuta crocuta ) by restriction fragment length polymorphism of amplified ZFX/ZFY loci

We describe a quick and efficient method of determining the sex of DNA samples in the hyena. By choosing primers from sequences that are conserved between the human and bovine ZFY and ZFX genes, we amplified a 448 bp fragment from 1 male and 2 female hyenas. Using comparative sequencing, single base pair polymorphisms between the amplified ZFY and ZFX were established. Restriction fragment length polymorphism (RFLP) analysis with PstI and TaqI confirmed the sequence data and yielded specific banding patterns between the 2 sexes in the hyena.