奶牛真胃左方变位的病因及发病机制

奶牛真胃变位是指真胃的正常解剖学位置发生改变，超出了正常的生理范围，而引起消化机能障碍，导致营养失调的急性内科疾病。在临床上可分为左方变位和右方变位。前者是真胃通过瘤胃底部从腹腔的右侧移至左侧，置于瘤胃与左侧腹壁之间，也称真胃移位；后者是真胃在右侧腹腔发生了不同程度的扭转，逆时针的称为前方变位，顺时针的称为后方变位，人们习惯于把右方变位称为真胃扭转。关于奶牛真胃左方变位的记载已有百年历史（Carougean和Prestat，1898），自1950年由Begg氏和Ford氏描述和确认以来，近50年内，该病在世界许多国家的发病率逐年增高，死亡率也较高，造成的经济损失严重，成为威胁奶牛健康发展的一种严重疾病。其中，奶牛真胃左方变位的发病率最高。要预防真胃变位的发生，就需要研究和探索真胃变位的病因和发病机制，以便采取相应的措施，有效预防、控制该疾病的发生。真胃变位的发病因素较多、较为复杂，迄今为止，人们对其病因及发病机制尚无一致性结论，但认为真胃左方变位和右方变位的病因相似。本文结合作者的研究和临床工作，对奶牛真胃左方变位的病因及发病机制的研究现状进行综述。     

奶牛真胃变位的研究进展

随着奶牛饲养集约化的程度越来越高,奶牛真胃变位的发生和死亡率也呈上升趋势,造成日渐严重的经济损失,对奶牛业健康发展构成了严重的威胁,因此对奶牛真胃变位的病因及防治方法探讨很有必要.文章就近年来有关奶牛真胃变位的病因和发病机理、临床症状、诊断及治疗方法、研究进展进行综述.     

奶牛皱胃右方变位诊断与治疗

随着养牛业的发展,奶牛皱胃变位作为一种常见的生产性疾病,不仅影响奶牛的产奶量,而且还影响奶牛的生产繁殖,严重威胁着养牛业的发展。由于该病的临床诊断较为困难,误诊和治疗不当而引起死亡的病例不少,而因被误诊的病牛因长期治疗也耗费了大量的药费。研究反刍动物真胃变位疾病受到国内外畜牧兽医工作者的高度重视。按其皱胃变位的方向分为左方变位和右方变位两种类型。2009年7月17日在天山农牧业有限责任公司实训中遇见该病,病畜是一例美国荷斯坦奶牛,耳号为TY-05006。本文主要讨论该病的病因、发病机制、临床症状、诊断方法、治疗以及预防。     

奶牛真胃变位研究概况

奶牛真胃变位是奶牛真胃的解剖位置发生改变引起消化机能严重紊乱、导致营养代谢失调的急性外科病，可分为左方变位和右方变位。临床上以真胃左方变位最常见，随着奶牛集约化饲养规模的扩大，其发病率有逐年增加的趋势。国外早在50年代就有该病的报道，特别是一些奶牛养殖业发达的国家。黑白花奶牛的发病率高达1．5％以上。而我国对本病的研究相对滞后，一方面原因是我国奶牛饲养相对粗放，奶牛真胃变位的发病率不高：另一方面是我国兽医工作者对真胃变位的认识不足。许多真胃变位病例得不到确诊。近几年来，随着我国奶牛饲养量的扩大，集约化程度不断提高，再加上大量饲喂精料，盲目追求高产，奶牛真胃变位的发病率逐年上升，因此，人们对本病的认识也不断深化。尤其是我国大中城市的近郊区，该病的发病率很高。个别地区发病率达8％-10％，其中产后发病的高达85％以上，给奶牛业造成严重的经济损失。尽管国内外学者对该病研究报道很多，但多限于诊断和治疗的研究，有关病因和发病学的研究极少，发病机理尚不完全清楚，每年仍有大量奶牛产奶量下降甚至死亡。部分治愈的奶牛仍可复发本病或者是治愈后产奶量持续低下。基于此点，有必要对该病开展深入研究。本文以真胃左方变位为主，综述其发病原因、发病机制、临床诊断要点和治疗方法，以供兽医工作者和研究人员参考。     

奶牛真胃变位的诊断与治疗

真胃变位(abomasal displacement)是指真胃正常解剖学位置发生改变,引起消化功能障碍,导致营养失调的消化系统疾病。真胃变位是奶牛常见疾病,多发于高产奶牛分娩前后,一般情况下多发生左方变位,在断奶前一般发生右方变位。该病主要造成奶牛的淘汰率增加,生产能力下降,治疗费用增多,给奶牛养殖业造成严重损失。本文介绍在富宁兰养殖场实习期间遇到的奶牛真胃变位病例,并从发病原因、临床症状、诊断、治疗、预防等几个方面进行总结,以期为有效防治奶牛真胃变位提供参考。     

奶牛真胃变位发病原因研究进展

奶牛真胃变位的发病原因可能与真胃壁中肠道神经元功能性紊乱有关,这对揭示奶牛真胃变位的发病机制有重要意义.真胃变位奶牛肠道神经元的一氧化氮合酶活性升高,乙酰胆碱敏感性降低,真胃的运动力减弱和排空机能受损可能与这种异常关系有关,即抑制肠道神经元的增强活性,皱胃肌肉的胆碱能神经敏感性降低.流行病学调查和试验研究已证实真胃迟缓和真胃扩张是奶牛真胃变位的主要原因,同时,品种、遗传背景、双胎、泌乳早期阶段(特别是第1周)富含高精料日粮而缺乏优质粗饲料、代谢紊乱性疾病(酮病、脂肪动员增加、胰岛素抗药性)和其他并发疾病(子宫内膜炎、乳房炎、蹄病)等都是真胃变位发生的诱发因素.     

奶牛真胃变位的研究进展

奶牛真胃变位(displaced of abomasums,DA)是指真胃正常解剖位置发生改变,引起消化道梗阻,导致消化机能障碍的内科疾病,包括真胃左方变位(LDA)和真胃右方变位(RDA)。随着奶牛集约化饲养的扩大和产奶量的提高,奶牛DA的发病率逐渐升高,引起畜牧兽医界的关注和重视,人们对真胃变位的病因、机理、诊断治疗等方面都有了更新的认识。文章对近几年该病的发病机理、临床症状及治疗等方面的研究进展作一总结,为该病的防治提供理论资料。     

治疗奶牛真胃变位的体会

真胃变位是奶牛常见的真胃疾患,也是实施奶牛腹部外科手术的主要原因,该病高产奶牛易发,多数发生于分娩后几小时至数周,它可分为真胃左方变位和右方变位两种,而右方变位又分为后方扭转和右方扭转。据有关资料报道,真胃变位85％—88％发生在左侧,而右侧发病相对较少。     

奶牛真胃左方变位诊疗体会

真胃变位也叫真胃移位或皱胃变位,在临床上分为左方变位和右方变位。近几年奶牛真胃左方变位发病率比较高,笔者已接触100例左右。真胃右方变位较少遇到。现就临床诊治真胃左方变位过程中体会总结如下。     

奶牛真胃左方变位的诊治体会

奶牛真胃变位是指真胃正常解剖位置发生改变引起消化道梗阻,导致消化机能障碍的内科疾病,包括真胃左方变位和真胃右方变位。随着奶牛集约化饲养的扩大和产奶量的提高。奶牛真胃变位的发病率逐渐升高,引起畜牧兽医界的关注和重视。真胃左方变位用手术方法治疗疗效确实,见效快。     

奶牛真胃变位发病规律的研究

为了阐明奶牛真胃变位的发病规律，对263例奶牛患有真胃变位的自然病例进行了研究。结果表明：真胃变位的发生与过食精料和高产奶牛有密切关系，2－4胎次体格健壮的、产后30天内的、11月份到来年的5月份奶牛发病率高。     

奶牛真胃变位研究进展

奶牛真胃变位是危害集约化养牛尤其是高产奶牛的多发腹腔疾病之一。据变位部位不同又可分为左方变位和右方变位。本病的病因及发病机制目前尚无一致性结论：右方变位的临床症状比左方变位严重且病程较急;具有典型的示病症状,不难做出诊断;有保守治疗和手术治疗两种治疗方法,而对于右方变位手术治疗几乎是唯一的治疗方法;加强饲养管理、合理预防和及时治疗原发病可有效降低其发病率。     

Etiology and prophylaxis of reperfusion injuries]

In recent years the importance of oxyradicals in clinical veterinary medicine is incessantly grown. An important example in cattle breeding is the displaced abomasum in dairy cows. The antioxidative status of the animals is representable by means of the activity of superoxide dismutase (SOD) in the blood. Post operationem the activity of SOD decreased very fast. In cows with left abomasal displacement this activity increased within 24 hours to the starting level, but in cows with right abomasal displacement the SOD-activity in this period increased only insignificantly. Because of the low level of SOD-activity in blood serum the measuring should take place in erythrocyte lysate. Today there are many possibilities of therapeutical intervention of reperfusion injury, but their clinical efficiency has to be ascertained. The treatment of cows with displaced abomasum with ascorbate, tocopherole or prednisolone before the replacement of the abomasum shows first success in terms of the antioxidative and metabolic status.     

Possible association of vitamin A deficiency with displacement of the abomasum in dairy heifers

Clinical manifestations of anasarca, left displacement of the abomasum, abortion, and incoordination appeared in a group of heifers fed a vitamin A-deficient diet. Older heifers and heifers late in pregnancy were more affected. All clinical signs of disease disappeared within 14 days after vitamin A treatment was begun, and the diet was changed. Although vitamin A deficiency in dairy cows has been documented, this report differs from others in the main clinical manifestations of disease.     

Left abomasal displacement and ulceration in an eight-week-old calf

Left displacement of the abomasum was diagnosed radiographically in an 8-week-old female Friesian calf. At surgery, a 4 cm ulcer was repaired and an abomasopexy performed during closure of the abdomen. Recovery from surgery was slow, and regurgitation of rumen contents occurred. Despite medical treatment, the calf died 4 days later. Left abomasal displacement is a well documented disease of dairy cattle (Robertson 1968; Coppock 1974; Martin et al 1978a; Poulsen 1976), but in young calves the condition is rare (Dirksen 1981). This report describes a case of left abomasal displacement with ulceration in an 8-week-old female Friesian calf.     

奶牛皱胃变位病因及发病机制研究进展

奶牛皱胃变位是指皱胃的正常解剖位置发生改变,导致消化机能障碍的内科疾病。此病多发于高产奶牛,造成了巨大的经济损失。论文通过对遗传、品种、胎次及生产水平、发病时期、营养和新陈代谢及环境等来综述奶牛皱胃变位的病因,从皱胃弛缓学说和机械因素学说两方面综述其发病机制研究进展,为该病的有效预防和控制提供理论基础。     

奶牛皱胃变位的诊疗

在现代化奶牛饲养中，皱胃变位的发病呈增高趋势，是危害集约化养牛尤其是高产奶牛的多发疾病之一。本文分析了两例奶牛皱胃变位的发病原因及发病特点，结合临床症状，实施相应的治疗措施，取得了较好的效果。     

Torsion of the abomasum in ruminants: Diagrammatic representation of rotary movements based on post-mortem findings

Summary A theoretical analysis of the types of displacement of the abomasum in the abdomen is presented based on a stud of forty-seven post-mortem examinations of calves, cows, lambs and sheep showing right-sided abomasal displacement and production of knots. These displacements are quantified following the introduction of a dual-axial system. One system (XYZ) related to displacements of the abomasum on a pendulum model, the point of suspension being situated on the visceral surface of the liver and the arms consisting of parts of the digestive tract adjacent to the abomasum. The other system (x (1) y (1)z(1) ) comprises axes centered on the abomasum, about which this organ was able to rotate without changing its position in the abdomen. In order to make quantification of the displacements and deformations possible, the term twine is introduced. Twining results from interlacing of sections of the digestive tract, which are not normally adjacent. This limits the concept of torsion to helices appearing in the pyloro-duodenal region and the omaso-abomasal junction. To identify the various forms of abomasal displacement, a new terminology is introduced and basic elements suggested to make quantifications possible.     

Use of bovine somatotropin at the time of surgery for left displacement of the abomasum in dairy cows. Minnesota Dairy Practitioners Study Group

OBJECTIVE: To evaluate the effect of a single dose of recombinant bovine somatotropin (bST) on certain metabolic values, health, and milk production of dairy cows undergoing surgery for left displacement of the abomasum. DESIGN: Blinded clinical trial. ANIMALS: 413 cows with left displacement of the abomasum. PROCEDURE: A single 500-mg dose of bST was administered to dairy cows following surgery in field practice conditions for left displacement of the abomasum. A placebo of the same carrier without bST was administered to control cows in this blinded study. Metabolic and production responses in a short-term follow-up period were measured. RESULTS: Blood glucose concentrations in cows 3 to 5 days after surgery were statistically higher for treated cows than for control cows. A higher proportion of treated cows had improved urine ketone test results than did controls. Significant differences in other metabolic values, health, and milk production were not detected. CLINICAL IMPLICATIONS: Treatment of metabolically compromised cows with bST may have some positive effects, but further investigation is needed to confirm therapeutic value.