不同水平烟酸对青贮饲料营养成分在瘤胃内降解率影响的研究

利用 3只带有瘤胃瘘管的绵羊 ,饲喂不同水平的烟酸 (0mg ,1 0 0mg ,30 0mg) ,用尼龙袋法测定玉米青贮中干物质、粗蛋白质、有机物质在瘤胃中的降解率。结果表明 ,不同烟酸水平对玉米青贮营养成分的降解率无显著影响 (P >0 .0 5)。     

Effects of butyrate and insulin and their interaction on the DNA synthesis of rumen epithelial cells in culture

Summary Rumen epithelial cells (REC) were incubated in the presence of various concentrations of butyrate or insulin or with both of them, to obtain information on their effect on the DNA synthesis of cultured cells. The 24-h values of³H-thymidine incorporation into cellular DNA were measured in the presence of butyrate, insulin or butyrate plus insulin. While butyrate reduced DNA synthesis, insulin produced an increase over the control. Combined butyrate plus insulin treatment influenced the incorporation of label in accordance with the relative proportion of these two substances.     

犊牦牛胴体分割及肉块重量测定

对20头体重在30～50kg的犊牦牛进行屠宰，按有关标准进行胴体分割，并对分割肉块的重量进行测定。犊牦牛的胴体肉共分为15块，即后小腿肉、股内肉、臀部肉、膝圆肉、短腰肉、小腹肉、里脊肉、腰部肉、腹部肉、背部肉、肋条肉、胸部肉、肩部肉、颈部肉、前小腿肉。平均重量（kg）依次为：0．940；1．420；1．135；1．205；0．933；0．255；0．475；0．567；0．883；0．960；1．380；0．625；2．473；1．150；0．685。     

Isolation and Properties of Melanin in Fine Yak Hair

Melanin granules were isolated from fine yak hair by means of protein enzyme and hydrochloric acid.Resultsof SEM investigation and amino acid analysis were usedto study the physical and chemical properties of melaningranules.The solubility of melanin granules in differentchemical solutions was also studied.     

牦牛肝片吸虫四种抗原交叉免疫印迹分析

用牦牛肝片吸虫四种抗原分别制备四种抗血清，其ＥＳＩＳＡ效价 １：８００，１：１６００，１：３２００和１：８００．ＳＤＳ－ＰＡＧＥ电泳区带组分分别为２５，２４，１８和９条带；免疫印迹结果，各种抗清与相庆抗原作用的主要抗原成份分别为５，１０，７和３；四种抗原中存在的共同抗原为１７．２ｋＤ；特征抗原ＨＡ为２９．９ｋＤ，ＳＡ为２７．２ｋＤ的２４．３ｋＤ；正常兔血清与各个抗原间均未出现免疫反应。     

青海环湖型牦牛脾脏的形态观测

对青海环湖型牦牛脾脏的解剖观测表明,脾脏位于左季肋部瘤胃背囊左前背侧,呈脏面略凹,壁面稍凸,背侧端略宽,腹侧端稍窄的扁平长椭圆形。脾门位于背侧端的脏面近前缘处。脾脏长、宽、厚度分别为(52 11±4 18)cm,(13 26±1 17)cm、(1 29±0 28)cm,脾脏平均重(553 31±80 25)g,占体重的0 30%。     

高寒牧区牦牛子宫脱出的防治

手术整复和后海穴注射２％盐酸普鲁卡因是治疗子宫脱出的有效方法，加强怀孕牦牛的饲养管理，组织优良的改良群，正确的助产方法等预防措施可以减少该病的发生．     

Genetic polymorphisms of milk epithelial mucin of yaks

Milk epithelial mucin (MUC1) of yaks was separated by SDS-polyacrylamide gel electrophoresis. A total of nine types of MUC1 were revealed in 427 yaks from five yak breeds including Maiwa yak, Jiulong yak, Tianzhu white yak, Qinghai yak and Tibetan yak. The molecular weights of MUC1 are from 163 kD to 208 kD, most of which are larger than those of bovine. Population genetic analysis shows that the gene frequency and genotype frequency of yak MUC1 differ among breeds, with relatively high gene heterozygosity. The five yak breeds studied fall into two groups according to their milk MUC1 gene frequency, suggesting that milk MUC1 exhibits specificities for local yak groups.     

中国部分地方牛种mtDNA D-loop区全序列的遗传多样性与系统进化分析

利用PCR测序及生物信息学分析技术,对我国5个地方黄牛品种、5个地方水牛品种及2个地方牦牛品种的mtDNA D-loop区全序列进行PCR扩增以及核苷酸多样度、单倍型多样度分析,发现中国地方黄牛、水牛与牦牛具有丰富的遗传多样性.对试验牛mtDNA D-loop区全序列与牛亚科代表性物种黄牛、水牛、家牦牛、野牦牛、欧洲普通牛、印度瘤牛以及摩拉水牛相应序列进行系统发育分析.结果显示:黄牛与牦牛的亲缘关系较近,它们与水牛的亲缘关系较远;中国水牛属于沼泽型水牛,也有少量江河型水牛渐渗入中国水牛群体;中国黄牛为普通牛和瘤牛的混合母系起源;进化树显示高原牦牛与野牦牛的亲缘关系较近,环湖牦牛与家牦牛的亲缘关系较近.     

利用双向电泳-质谱技术鉴定牦牛和犏牛睾丸中的差异表达蛋白质

比较了牦牛和犏牛睾丸组织中蛋白质的表达差异;应用双向电泳-质谱技术,对牦牛和犏牛的睾丸组织中差异蛋白质进行分离和鉴定;对获得的22个差异表达点进行质谱鉴定和数据库搜索,获得了19个蛋白质,其中有3种分子伴侣可能与犏牛雄性不育有关;研究结果表明,牦牛和犏牛睾丸组织中存在差异表达蛋白,并可利用双向凝胶电泳进行分离,为进一步分析犏牛雄性不育的原因提供了线索.