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1.
    
This study presents a comparative morphological and morphometrical examination of the interosseous muscle (IOM), digital flexor tendons and associated structures of all four species of South American Camelids (SACs): Lama (Lama glama), alpaca (Vicugna pacos), guanaco (Lama guanicoe) and vicuna (Vicugna vicugna). Our findings show that the lamoid interosseous muscle and digital flexor tendons are very similar between species and differences, which have been reported previously, are possibly due to diverging examiner interpretation. Lumbricalis muscles were mostly found as single muscles in this study. The definition of the terminal and dorsal branches of the interosseous muscle is critically revised. The analysis of morphometric data indicates that the size of the individual has a substantial influence on the cross-sectional area (CSA) of the examined structures. Metacarpal/metatarsal bone width is a main predictor of CSA, while the factor species only shows significance in specific sample points. For lama and alpaca, no differences in CSA in relation to species as factor were found. The IOM shows the largest CSAs of the three examined structures in all species, which implies an important load-bearing function. Considerable individual variation remains unexplained by the mentioned factors. This lowers the prospect of CSA reaching diagnostic importance in SAC fetlock pathology.  相似文献   

2.
    
Variability in the technique employed for flexion tests may produce different responses and veterinary assessments. We propose a novel custom-designed dynamometer and compare the results with the literature. Ten horses were enrolled in the present study, with a total of 20 forelimbs. The horses were found to be healthy based on orthopaedic and radiographic examination of the distal forelimb region, performed on both limbs. Lower forelimb flexion tests were performed by applying three different forces (75, 100 and 120 N), measured with a dynamometer, for one minute, with a time interval of 48 h between each test. Each horse was trotted before and after the flexion test. The experiment was videotaped, and the responses were assessed randomly and blindly by three experienced equine veterinarians. None of the horses responded with a lameness grade exceeding 1/5 on a numerical 6-point scale. Two out of three veterinarians detected a increased degree of lameness between the minimum and the maximum force applied, while one veterinarian showed no change in the interpretation of the flexion test for all three applied forces. A mild agreement was detected between veterinarian A and B, applying a force of 100 N, and between A and C, with 120 N; a moderate agreement was found between veterinarian A and B, with 120 N. The chi-square test showed that the results observed were only like the expected ones for 100 N. With a force of 100 N, there is no relationship between intensity and the evaluation of lameness; consequently, 100 N could be used to achieve a real standardisation of the lameness score. The use of the dynamometer was found to be easy and practical. It also enabled the applied force and the manipulation technique to be objectified.  相似文献   

3.
对北极狐骨骼系统进行解训观察,同时与革食动物马、牛及杂食动物猪的骨骼作形态学上的比较。由于生活习性所致,北极狐骨骼形态结构具有如下特征:北极狐的骨骼由头骨、躯干骨和四肢骨组成。头骨的主要特征是:枕骨的颈交不发达,眶上突不与颧弓相连,无眶上孔;颞骨岩部形成半球形鼓泡,鼻骨与颌前骨的鼻突之间不形成鼻颌切迹;泪骨几乎无颜面部;颌前骨的鼻突发达;上颌骨外面无面嵴;腭骨发达;犁骨腹缘后部不与鼻腔底壁接触;下颌骨支下缘无血管切迹、垂直部后下方有一角突。四肢骨的主要特征是:肩胛岗下端形成肩峰;臂骨未见三角肌结节和圆肌结节;尺骨比桡骨细长;腕骨7块;掌骨5块;指骨5指;左右髋骨几乎平行排列,坐骨弓宽平,荐结节高出荐骨;股骨有发达的大转子和较发达的小转子,缺第三转子;腓骨与胫骨等长;跗骨7块;躯干骨由7个颈椎、13个胸椎、7个腰椎、3个荐椎、15—17个尾椎组成;肋骨13对;胸骨由8个长柱状的胸骨节片和剑状软骨构成。  相似文献   

4.
禾本科植物叶片比较解剖的研究进展   总被引:3,自引:0,他引:3  
禾本科是单子叶植物中的一个大科,国内对其已有较多方面的研究。从分类学、生态学两个方面综述了我国禾本科植物叶片比较解剖的研究历史,意义和研究成果,禾本科植物叶片的解剖结构特征可以作为该科植物分类的重要依据,不同的叶片解剖结构反映了禾本科植物对不同环境条件的适应。综合现有的研究成果提出了禾本科植物叶片比较解剖研究中存在的问题和今后的研究方向。  相似文献   

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6.
    
The detailed coronary arterial anatomy of seven camels was studied and compared with that of horses and cattle. In camels, there is a bilateral coronary supply, the right coronary artery being the larger. The left coronary artery follows the same pattern as that in horses. The ramus collateralis proximalis in camels separates off some distance away from the origin of the ramus interventricularis paraconalis, as in horses, whereas it separates off very quickly in cattle. The ramus collateralis distalis has two branches in camels, whereas the left distal ventriculi ramus does not branch. The ramus angularis is also absent but the left distal atrii ramus is present.Abbreviations LCR left ramus circumflexus - RCR right circumflexus ramus - RIS ramus interventricularis subsinosus - RIVP ramus interventricularis paraconalis  相似文献   

7.
    
Cheek pouches have evolved from the oral cavity in rodents and act as temporary food storage repositories. There are two types of opening, internal and external. Details about the complex cutaneous muscles controlling the pouches have still not been fully elucidated. To understand the shared and derived traits of the muscles surrounding the cheek pouch and their innervation, we carried out an evolutionary morphological study using two desert kangaroo rats (Dipodomys deserti) and three plains pocket gophers (Geomys bursarius) from each of the two families equipped with external cheek pouches, and four Syrian hamsters (Mesocricetus auratus) with internal cheek pouches. The most conspicuous derived trait of the muscles between the external and internal cheek pouches, the sphincter sacculi, surrounds almost all of the edge of the outer entrance of the pouch. It is present in both species with external pouches, but not in hamsters, which have internal pouches. Our neurological findings demonstrate that most pouch muscles are innervated by both the facial and the cervical nerves, regardless of the pouch type. In these dually innervated muscles, the ventromedial part of the muscles tends to be innervated dominantly or uniquely by the cervical nerves, which usually enter from the superficial or lateral aspect. As a trait shared with the cervical nerves innervating the propatagial muscles in aerodynamic mammals such as bats and flying squirrels, and panniculus carnosus in most mammals, our neurological evidence suggests that the cervical nerve has the potential to innervate derived cutaneous muscles in the cervicofacial region.  相似文献   

8.
    
Flexural and hyperextension deformities are congenital problems in calves. We, therefore, aimed to investigate the distal limb conformation in 1 day- and 28-day-old female Holstein-Friesian (HF) calves (n=21), male Japanese Black (JB) calves (n=15), and female JB calves (n=15). The claw angle of the forelimb dorsal claw wall in a standing position and recorded other parameters, including body weight, withers height, circumference of forelimbs, and flexor tendon thickness in the forelimbs, were measured and compared these between the three groups. At 1 day old, the mean claw angles were 51.1° in female HF calves, 47.0° in male JB calves, and 41.8° in female JB calves; the 95% confidence intervals (CIs) of the claw angles showed large distributions in all three groups. One female HF and one male JB calves showed mild flexural deformity, whereas four JB calves showed hyperextension deformity. At 28 days old, the mean claw angles were 51.7° in female HF calves, 51.2° in male JB calves, and 48.4° in female JB calves; the 95% CIs of the claw angles showed smaller distributions than those at 1 day old in all groups. For all groups, the limb deformities had improved without treatment at 28 days old. As a feature of the breed, female JB calves were apt to show hyperextended deformities inversely proportional to the body weight. These limb deformities healed spontaneously and were thought to be physiological.  相似文献   

9.
10.
哺乳动物卵泡发育是一个被众多内分泌、旁分泌和自分泌因素精确调控的生理过程 ,本文结合本试验的研究工作 ,综述了卵泡早期发育调控的研究进展  相似文献   

11.
哺乳动物胚胎生物技术应用中线粒体的命运   总被引:1,自引:0,他引:1  
胚胎生物技术是生命科学的重要组成部分,包括体外受精、显微受精、细胞核移植技术等。线粒体是真核细胞中的重要细胞器,是机体的能量代谢中心。作者系统地就线粒体在体外受精与显微受精、细胞核移植技术等胚胎生物技术应用中的命运作一概述。  相似文献   

12.
随着克隆技术的发展,哺乳动物体细胞克隆在生物学、医学等领域有着越来越重要的价值,近年来,克隆技术不断完善,克隆方法不断优化,取得了很多重要的成果,但在成功率等方面仍存在许多难以攻破的问题。作者重点阐述了胞质内全细胞直接注射法这一技术在哺乳动物体细胞克隆上的应用情况,旨在阐明国内外哺乳动物体细胞克隆的研究现状,为进一步提高克隆成功率提供参考。  相似文献   

13.
近几十年来人们对动物的性别控制进行了大量的研究,其中X精子和Y精子的分离技术被广泛应用于哺乳动物性别的控制。论述了哺乳动物X精子和Y精子分离的方法,并简述了X精子和Y精子分离技术存在的问题及其发展前景。  相似文献   

14.
袁曦 《中国畜牧兽医》2013,40(2):103-107
防御素是广泛分布于动植物界的一类富含半胱氨酸的内源性阳离子抗菌肽,它在先天性免疫系统宿主防御机制中起着重要的作用。笔者从哺乳动物β-防御素的组成分布入手,对β-防御素的分子结构与染色体定位、基因表达调控、生物学作用及应用前景等最新研究作一全面综述。  相似文献   

15.
    
Hemoplasmas were detected in two apparently healthy captive South American coatis (Nasua nasua) from southern Brazil during an investigation for vector-borne pathogens. Blood was subjected to packed cell volume (PCV) determination, a commercial real-time PCR panel for the detection of Anaplasma spp., Babesia spp., Bartonella spp., Hepatozoon spp., Leishmania spp., Mycoplasma haemofelis, ‘Candidatus Mycoplasma turicensis’, ‘Candidatus Mycoplasma haemominutum’, Neorickettsia risticii, Rickettsia rickettsii and Leptospira spp., and a pan-hemoplasma conventional PCR assay. PCV was normal, but both coatis tested positive for hemoplasmas and negative for all the remaining pathogens tested. Using different techniques for microscopy (light, confocal or SEM), structures compatible with hemoplasmas were identified. Sequencing of the 16S rRNA gene identified an organism resembling Mycoplasma haemofelis and another hemotropic Mycoplasma sp., with a sequence identity of 96.8% to a Mycoplasma sp. previously detected in capybaras.  相似文献   

16.
On rangelands worldwide, cattle interact with many forms of biodiversity, most obviously with vegetation and other large herbivores. Since 1995, we have been manipulating the presence of cattle, mesoherbivores, and megaherbivores (elephants and giraffes) in a series of eighteen 4-ha (10-acre) plots at the Kenya Long-term Exclosure Experiment. We recently (2013) crossed these treatments with small-scale controlled burns. These replicated experimental treatments simulate different land management practices. We seek to disentangle the complex relationships between livestock and biodiversity in a biome where worldwide, uneasy coexistence is the norm. Here, we synthesize more than 20 yr of data to address three central questions about the potentially unique role of cattle in savanna ecology: 1) To what extent do cattle and wild herbivores compete with or facilitate each other? 2) Are the effects of cattle on vegetation similar to those of wildlife, or do cattle have unique effects? 3) What effects do cattle and commercial cattle management have on other savanna organisms? We found that 1) Cattle compete at least as strongly with browsers as grazers, and wildlife compete with cattle, although these negative effects are mitigated by cryptic herbivores (rodents), rainfall, fire, and elephants. 2) Cattle effects on herbaceous vegetation (composition, productivity) are similar to those of the rich mixture of ungulates they replace, differing mainly due to the greater densities of cattle. In contrast, cattle, wild mesoherbivores, and megaherbivores have strongly guild-specific effects on woody vegetation. 3) Both cattle and wild ungulates regulate cascades to other consumers, notably termites, rodents, and disease vectors (ticks and fleas) and pathogens. Overall, cattle management, at moderate stocking densities, can be compatible with the maintenance of considerable native biodiversity, although reducing livestock to these densities in African rangelands is a major challenge.  相似文献   

17.
哺乳动物的极体   总被引:2,自引:0,他引:2  
长久以来 ,人们都认为极体在正常情况下不参与动物的胚胎发育而退化 ,是无功能的小细胞。但实验证明极体含有的染色体与留在卵母细胞中的染色体具有同等的遗传潜力。在小鼠上 ,人们将其极体与去核卵母细胞或者去核合子融合 ,构成的重构卵母细胞受精后和重构胚都能发育 ,移植后均产生正常生殖力的后代。研究还发现极体的形成与细胞骨架密切相关 ,而其退化则可能是一个凋亡过程。极体作为雌性染色体的来源 ,可以用于建立种子库 ,并能从一个卵母细胞得到四个基因型相同的后代 ,在人类临床上极体可用作孕前遗传疾病的检查材料 ,减少了操作对胚胎的损伤。对极体还需要做进一步的研究。  相似文献   

18.
目前,已发现了许多与氧感受器相关的基因,如血红素蛋白、NADPH氧化还原酶、线粒体电子传递链成分、天冬酰胺羟化酶及HIF1等。虽然低氧研究在哺乳动物的器官水平及分子水平取得了很大的进展,但是低氧信号传导机制并不是很清楚。作者综述了高原地区哺乳动物低氧感受器方面的进展,通过对高原地区哺乳动物机体对低氧适应的机制进行总结,帮助人们了解哺乳动物对高原低氧环境的适应机制。  相似文献   

19.
异种核移植是在同种核移植基础上发展起来的动物生殖技术,在生物学研究方面具有重要的理论价值,如研究核质相互作用。同时,异种核移植在畜牧业生产、医学临床和濒危动物拯救等方面具有独特的意义。目前,异种核移植技术还处于探索发展阶段,还有许多问题需要研究解决。文章介绍了哺乳动物异种核移植技术发展的历史、研究的热点、现状与取得的成果。同时,分析了影响异种核移植的因素、尚未解决的问题和该技术的发展和应用前景。  相似文献   

20.
大豆黄酮对大鼠、猪和奶牛泌乳及有关内分泌影响的研究表明,大豆黄酮具有弱的雌激素样活性,可促进哺乳动物的乳腺发育和有关的内分泌活动,影响机体的代谢活动和乳汁成分。  相似文献   

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