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朱永成 《青海畜牧兽医杂志》2012,42(5):37-38
1现状1.1犏牛的一般生物学特性依托项目发展,2012年莫河骆驼场开始大面积养殖犏牛,犏牛是普通牛与牦牛杂交后产生的后代,普通公牛与母牦牛杂交,其杂种称"真犏牛",公牦牛与普通母牛杂交,其杂种称"假犏牛"。无论"真"、"假"犏牛雄性均不育。犏牛无论 相似文献
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犏(pian)牛为牦牛与黄牛一代种间杂交所生产的后代.以黄牛作为父本、牦牛作为母本繁殖的犏牛,称为真犏牛(或称正交犏牛);以牦牛作为父本、黄牛作为母本繁殖的犏牛,称为假犏牛(或称反交犏牛). 相似文献
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研究旨在通过利用GPS跟踪定位技术对祁连山区秋季牧场上24h自由放牧牦牛和犏牛的昼夜采食活动进行对比研究。选取甘肃天祝藏族自治县乌鞘岭地区牦牛和犏牛各3头,在2012年9月30日至10月25日利用家畜GPS跟踪定位系统进行家畜牧食行为的研究,通过计算它们的水平游走距离,分析牦牛和犏牛在秋季牧场的昼夜采食活动。结果表明:(1)在24h内,牦牛和犏牛都表现出3个采食高峰期,第一个高峰期在9∶00~10∶00左右;第二个在18∶00左右;第三个在23∶00左右。在整个试验过程中,犏牛的采食活动量显著高于牦牛(P0.05);在试验的前半期(牧草初黄期)犏牛和牦牛的采食活动量差异不显著(P0.05);而在试验的后半期(牧草枯黄期)犏牛的采食活动量极显著高于牦牛(P0.01);犏牛和牦牛牧草枯黄期的采食活动量都极显著高于牧草初黄期采食活动量(P0.01)。(2)同一牧场上放牧的牦牛和犏牛在牧草初黄期采食活动范围相似,而在牧草枯黄期二者的采食空间分布格局出现了分化,犏牛的采食活动范围变得相对狭长,牦牛的则变得相对宽广。研究结果表明当秋季牧场牧草大面积枯黄的时候,需要对家畜进行适当补饲,进而满足家畜的生长需求,同时减少由于游走觅食活动等造成的能量消耗。通过对比牦牛与犏牛的牧食活动,牦牛较犏牛更加适应青藏高原的严酷环境条件,尤其在缺草季节,牦牛的适应性更加明显。 相似文献
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犏牛高效生产新模式的建立 总被引:1,自引:0,他引:1
《中国兽医学报》2019,(5):1007-1013
犏牛是牦牛与奶(肉)牛杂交的后代,具有明显的杂种优势,是牦牛育种改良的重要方向之一。由于雄性犏牛不育,杂种优势无法稳定遗传。因此,利用现代繁殖育种技术是解决此问题的关键。本研究利用牦牛屠宰场的卵巢收集卵母细胞,与奶(肉)牛的冻精进行体外受精,将获得的胚胎移植到同期发情的犏牛体内,建立生产犏牛新模式。结果表明,用荷斯坦牛、西门塔尔牛和娟姗牛的冻精与牦牛卵母细胞体外受精,受精率无显著差异(P0.05),但显著高于牦牛种内体外受精(P0.05)。胚胎发育动力学结果表明,犏牛胚胎的体外发育速率显著高于牦牛胚胎(P0.05);雄性犏牛胚胎的发育显著快于雌性胚胎。用孕酮阴道栓、马绒毛膜促性腺激素(eCG)和氯前列腺烯醇(PG)组合的同期发情处理方案,诱导犏牛发情效果较好,发情率显著高于单独使用PG组(P0.05)。获得了全球首批试管犏牛(7头),实现了犏牛生犏牛新模式。获得的试管犏牛体型丰满、生长迅速、1周岁的体质量达160 kg,是同龄牦牛的2倍。综上,本研究建立了一套高效的犏牛体外生产技术体系,充分利用了母犏牛的繁殖性能,为挖掘优秀母犏牛的繁殖潜能和加速扩繁犏牛奠定了基础,对实现少数民族地区牧民增收与生态保护具有重要的意义。 相似文献
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通过采用犏牛、牦牛犊牛培育技术结合设施化养殖技术,研究不同的饲养方式对犏牛、牦牛生长发育、增重效果及屠宰率的影响,研究结果表明,采用犊牛培育技术,6月龄犏牛公犊牛和牦牛公犊牛的体高、体斜长、胸围、管围都有不同程度的增长,体重也明显增加,与对照组相比,差异显著(P<0.05);采用设施化养殖技术,犏牛设施组的总增重及平均日增重显著高于牦牛对照组,差异显著(P<0.05);牦牛设施组、犏牛对照组和犏牛设施组的总增重及平均日增重显著高于牦牛对照组,差异显著(P<0.05)。犏牛设施组胴体重及净肉重分别为138.27±3.17kg和113.29±2.87kg,屠宰率和净肉率分别为58.47%和47.91%,犏牛设施组屠宰率和净肉率显著高于犏牛对照组,差异显著(P<0.05);牦牛设施组胴体重及净肉重分别为99.09±2.35kg和79.83±1.91kg,屠宰率和净肉率分别为57.46%和46.29%,与牦牛对照组和犏牛对照组相比,牦牛设施组和犏牛设施组的屠宰率和净肉率显著高于牦牛对照组和犏牛对照组,差异显著(P<0.05)。采用犏牛、牦牛犊牛培育技术结合设施化养殖技术,犏牛、牦牛的生长发育速度显著提高,总增重、日增重、屠宰率和净肉率显著高于传统放牧条件下的犏牛和牦牛。 相似文献
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揭示了(西×黄) ♂×牦牛♀和(黑×黄)♂×牦牛♀两个牦牛三元杂交组合繁殖的F1代犏牛生长发育情况,结果表明,F1代犏牛各年龄段的体尺、体重杂种优势明显,且母犏牛提前1~2岁投入生产,建议在牦牛杂交改良中推广这两个牦牛三元杂交组合. 相似文献
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《青海畜牧兽医杂志》2017,(3)
犏牛是牦牛与肉牛、普通牛、奶牛以及黄牛的杂交F1代,杂种优势明显,在产肉、产奶等生产性能方面明显优于亲本牦牛,然而犏牛雄性不育的问题却严重地影响了犏牛的利用价值,阻碍了犏牛产业的发展。近年来,有许多国内外学者针对犏牛雄性不育的问题,进行了研究讨论。文章针对近年来有关犏牛雄性不育的研究成果、目前的研究进程和今后的研究方向等方面进行了阐述。以便全方位了解犏牛雄性不育的研究状况,促进犏牛雄性不育的研究进程。 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