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对生活在不同海拔地区的牦牛肺组织进行观察和测量,结果表明:在单位面积内,高海拔地区牦牛的肺泡数(34.62±5.15个/mm2)多于低海拔地区牦牛的肺泡数(27.19±4.37个/mm2)(P<0.01),肺泡隔厚度(3.52±0.58μm)大于低海拔牦牛(2.78±0.42μm)(P<0.01)。 相似文献
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本研究旨在探讨牦牛细胞质苹果酸脱氢酶(cytoplasmic malate dehydrogenase,MDHⅠ)基因的遗传多态性及其与生长性状的关联性,以期为牦牛优良性状选育提供参考依据。选取5个牦牛类群(共178头),采集耳组织样提取DNA并构建DNA池,对MDHⅠ基因所有外显子设计特异性引物进行扩增测序,用Mega 5.2筛查SNPs位点,直接测序法鉴定其基因型,利用PopGene 32进行χ~2独立性检测、基因纯合度(Ho)、基因杂合度(He)、有效等位基因频率(Ne)和多态信息含量(PIC)分析,利用SPSS 24.0分析MDHⅠ基因与牦牛生长性状间的关联性。结果表明,申扎牦牛、类乌齐牦牛、斯布牦牛、帕里牦牛和麦洼牦牛均在外显子8区域发现1个突变位点(G23093C),属同义突变,有3种基因型:GC、CC和GG,5个牦牛类群中,GC基因型为优势基因型(类乌齐牦牛中GG为优势基因型),G为优势等位基因(斯布牦牛除外),在斯布牦牛中,G和C基因频率相等。χ~2适应性检验表明,申扎牦牛、类乌齐牦牛、斯布牦牛、帕里牦牛和麦洼牦牛均符合Hardy-Weinberg平衡(P0.05)。MDHⅠ基因在申扎牦牛、帕里牦牛和斯布牦牛中属于高度多态(PIC0.5),在麦洼牦牛和类乌齐牦牛中属于中度多态(0.25PIC0.5);纯合度最高的是申扎牦牛和类乌齐牦牛。关联性分析结果表明,MDHⅠ基因不同基因型对类乌齐牦牛、帕里牦牛和麦洼牦牛体重有显著性影响(P0.05);且种间分析发现,MDHⅠ基因不同基因型对牦牛体重有显著性影响(P0.05),说明该基因可作为人工选育的分子标记。 相似文献
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旨在研究褪黑素对妊娠牦牛子宫的调控作用,采用real-time PCR法和免疫组织化学S-P法,对未妊娠和妊娠不同时期牦牛子宫中褪黑素受体(MT1)mRNA和褪黑素受体(MT1)蛋白的表达进行研究。结果表明:牦牛未妊娠和妊娠的不同时期,牦牛子宫基质细胞(SC)和肌层平滑肌细胞(MM)中均有MT1蛋白表达(P0.05);血管内皮细胞(EBV)和血管平滑肌细胞(VSM)中的MT1蛋白表达,在妊娠28~35d差异不显著,随妊娠时间的增加,MT1蛋白表达增加(P0.05);腺上皮细胞(GE)中的MT1蛋白,在妊娠初期(妊娠28~35d)差异不显著,妊娠50~60d时,差异显著(P0.05),妊娠90~100d时,差异极显著(P0.01)。而在腔上皮细胞(SE)中,MT1蛋白表达量在妊娠28~35d比未妊娠时低(P0.05),而这种趋势随妊娠时间的增加继续降低(P0.01)。未妊娠牦牛子宫中MT1mRNA表达量显著高于妊娠牦牛(P0.01)。综上表明,在妊娠期,牦牛子宫对褪黑素的需求量降低,褪黑素主要作用于牦牛GE,调节子宫腺功能,使牦牛子宫产生适应妊娠的生理反应。 相似文献
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[目的]为明确高寒牧区牦牛冷季补饲效果。[方法]本试验通过测定日增重和采集血液去分析补饲精饲料对不同年龄那曲牦牛生长速度和血液生化指标的影响。[结果]研究表明,2岁、3岁牦牛试验组和对照组的日增重均显著高于1岁、4岁(P0.05);在不同年龄间,牦牛各个年龄的试验组日增重均高于对照组,但1岁、2岁试验组极显著高于对照组(P0.01),3岁、4岁试验组日增重显著高于对照组(P0.05)。不同年龄阶段淀粉酶(AMY)、尿素氮(BUN)、尿素(UREA)差异极显著(P0.01),钙(Ca)、磷(P)和尿素氮/肌酐差异显著(P0.05)外,其余指标差异均不显著(P0.05),同一年龄的牦牛在不同的饲养管理水平下,各项生化指标中补饲牦牛的淀粉酶(AMY)、尿素氮(BUN)、尿素(UREA)极显著高于放牧牦牛(P0.01),钙(Ca)和尿素氮/肌酐显著高于放牧牦牛(P0.05),磷(P)显著低于放牧牦牛(P0.05)。[结论]表明冷季补饲有效补充了那曲牦牛的机体能量,为其机体冷季正常生长发育提供了动力,从而提高了其越冬能力和适应性。 相似文献
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旨在阐明不同毛色牦牛皮肤组织形态学特点及MC1R调控黑色素合成的可能分子机制。采集大通牦牛(黑褐色)和天祝白牦牛(白色)各6头的背部皮肤组织,用甲苯胺蓝染色法分别对不同毛色牦牛皮肤组织进行染色,观察黑色素和成熟黑色素细胞的含量差异及分布特征,并通过实时荧光定量PCR(qRT-PCR)检测MC1R在不同毛色牦牛皮肤中的表达差异。B16小鼠黑色素瘤细胞中转染shRNA MC1R干扰载体后,应用qRT-PCR和Western blot检测转染效率,分析比较各组中与毛色相关基因(Agouti、MITF、TYR)的表达差异性,利用酶标仪检测不同时间点黑色素产量。结果表明,两种毛色牦牛的表皮和毛囊周围均分布着大量的黑色素细胞,但天祝白牦牛仅在表皮基底层和毛根处检测到少量黑色素,而大通牦牛表皮层和毛囊处产生大量黑色素。与大通牦牛相比,天祝白牦牛皮肤中MC1R表达量极显著降低(P0.01)。在成功抑制MC1R的B16细胞中,TYR表达量极显著降低(P0.01),MITF表达量显著降低(P0.05),而Agouti表达量未发生显著变化(P0.05);同时黑色素含量减少。综上表明,黑色素大量沉积与MC1R高表达是导致牦牛毛色差异的原因。将shRNA MC1R载体成功转染B16小鼠黑色素瘤细胞后,MC1R的抑制情况与下游调控基因TYR表达一致,进而降低黑色素含量,说明MC1R对黑色素的合成及毛色形成起重要的调控作用。 相似文献
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本研究旨在探讨G蛋白偶联受体41(GPR41)基因在牦牛中的遗传多态性,对麦洼牦牛(50头)、申扎牦牛(47头)和类乌齐牦牛(28头)GPR41基因外显子区域片段进行扩增,筛查SNPs位点,利用RFLP分子标记技术鉴定其基因型,开展其与生长性状间的关联分析,为牦牛品种改良和选育提供遗传学依据。结果表明:在麦洼牦牛中未发现突变位点,申扎和类乌齐牦牛在外显子2区域发现1个突变位点,第4570位碱基发生G→A突变,属同义突变;经RFLP鉴定出3种基因型,命名为AA、AG和GG;χ~2适应性检验显示,申扎牦牛基因型分布不符合Hardy-Weinberg平衡(P<0.01),类乌齐牦牛处于Hardy-Weinberg平衡(P>0.05);申扎牦牛和类乌齐牦牛均表现为中度多态;GPR41基因不同基因型与申扎牦牛体重和体高显著相关,且GG型显著高于AA型(P<0.05),而GPR41基因不同基因型对类乌齐牦牛各体尺性状无显著性影响(P>0.05)。综上,申扎牦牛GPR41基因G4570A基因座可为牦牛选育过程中分子标记选择提供参考。 相似文献
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2004年8、9和11月份在青海省三角城种羊场夏、秋、冬三季牧场研究了牦牛的昼牧食行为。结果表明:牦牛在夏季草场的昼采食时间最长,平均为(337.45±39.96)min,在秋季和冬季草场的平均昼采食时间分别为(301.82±27.91)min和(304.57±12.24)min。另外,在夏季草场没有观测到牦牛的昼卧息和反刍行为。其主要原因是在夏季草场牛羊放牧压力过大,草地不能为牦牛提供足够的饲草,故牦牛延长采食时间以获取最大量的饲草,因此用于其他行为的时间相对减少。牦牛在秋冬季草场的昼反刍时间分别为(86.22±14.24)min和(53.84±13.93)min,秋季草场高于冬季草场。牦牛在秋季草场的昼站立和游走时间也高于夏季草场和冬季草场。其主要原因是由于秋季草场草产量丰富,质量较好。由于冬季草场气候寒冷,牧草枯黄,质量降低,牦牛的昼卧息时间最长。 相似文献
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为了研究青藏高原不同季节牧场牦牛的牧食行为规律,选取6头年龄、体况大致相同的成年牦牛作为研究对象,在2014年4月份和8月份分别在冬季牧场和夏季牧场上,运用GPS3300定位追踪系统,对自由放牧条件下牦牛的牧食行为进行了研究。结果表明:冬季牧场早上初牧9∶00、10∶00和下午归牧前17∶00、18∶00外界气温处于牦牛等温区内,有利于牦牛进行采食活动,而夏季牧场日平均气温的变化均高出牦牛活动的等温区(8~14℃),对其采食活动具有影响;夏季牧场上牦牛采食的空间分布由中心向四周辐射且个体间相对分散,冬季牧场上采食分布相对集中,夏季牧场上牦牛游走距离(0.29~0.80km/h)整体大于冬季牧场(0.07~0.14km/h),并且在11∶00和17∶00分别出现峰值,在12∶00游走距离最短;在监测期内(9∶00~18∶00),夏季牧场上牦牛各主要放牧行为的总体时间分配顺序依次是采食(504.90min)行走(75.45min)休息(55.10min),并且差异性显著(P0.05);冬季牧场牦牛的休息时间(355.80min)显著大于采食时间(243.10min)(P0.05)。研究结果显示,初牧和归牧前是牦牛放牧采食的剧烈活动时间,另外在夏季的中午13∶00左右也会出现一个采食高峰;牦牛的牧食行为符合晨昏活动格局,总体上表现出采食-休息(反刍)-采食的活动规律。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献