人工诱发产蛋鸡脂肪肝出血综合征的研究

通过外源性注射雌激素、高能低蛋白日粮及不同油脂来源的高能日粮人工诱发蛋鸡FLHS。90只40周龄海兰灰商品蛋鸡常规笼养,随机分为9组（10×9）：基础日粮组、基础日粮注射玉米油组、基础日粮注射β-雌二醇组;高能低蛋白日粮组、高能低蛋白注射玉米油组、高能低蛋白日粮注射伊雌二醇组;牛油高能日粮组、鸡油高能目粮组、豆油高能日...     

蛋鸡脂肪肝综合征的病因及其发病机理

脂肪肝综合征(Fatty 1iver Syndrome，FLS)或叫脂肪肝出血综合征(FLHS)是一种脂类代谢紊乱疾病。该病普遍发生于笼养蛋鸡，已成为很多国家的常见病。我国各地均有发生，发病率常在5％左右，占全部死亡鸡的8％～10％。此病多发生于产蛋量高峰期膘情良好的蛋鸡，引起产蛋量逐渐下降(2％～50％)。它给现代密集型养禽业带来了严重的经济损失，因此引起世界各国的重视。     

蛋鸡脂肪肝出血综合征病因分析及防治对策

蛋鸡的脂肪肝出血综合征是一种营养代谢病．笔者在基层临床工作中常见．主要表现过度肥胖．产蛋下降并突然死亡。该病多出现在产蛋高的鸡群或产蛋的高峰期．病鸡状况良好，剖检其肝脏、腹腔及皮下有大量的脂肪蓄积．常伴有肝脏小血管出血，并使肝脏下形成血肿，该病发病突然，死亡率高，给蛋鸡养殖业造成较大的经济损失。     

Evaluation of factors associated with infection of commercial layers with Mycoplasma gallisepticum and M. synoviae

Information on factors possibly associated with the risk of infection with Mycoplasma gallisepticum (MG) or M. synoviae (MS) were collected from nearly 400 layer flocks in California. Factors associated with the probability of flock infection with either MG or MS were identified, and their magnitude was quantified by statistical analysis. More frequent administration of several vaccines was associated with decreased probability of both MG and MS infection of flocks. Also identified were housing or hygiene factors and system of management (i.e., multiple-age status) that could reduce the probability of infection of flocks with mycoplasma. The change in probability of MG infection resulting from modifying certain management factors was examined.     

Influence of F strain Mycoplasma gallisepticum infection on response of commercial layers to heat exposure

Commercial layers were inoculated with F strain Mycoplasma gallisepticum (MG) and housed in either conventional chicken houses or the lower-stress environment of biological isolation units. At the end of 2 weeks, all treatment groups were placed in environmental chambers and subjected to 4 hr of heat stress (40 C with a dew point of 21 C). Rectal temperature, an indicator of response to high heat, was monitored. Rectal temperatures of F strain MG-inoculated hens housed in the conventional chicken house environment were significantly higher than those of uninoculated controls, whereas rectal temperatures of hens held in isolation units were comparable to those of their uninoculated controls.     

试验性脂肪肝出血综合征鸡氧化应激水平和内皮功能变化

将320只14日龄青脚麻鸡随机分为对照组、高脂模型组、雌激素模型组和高脂结合雌激素模型组,每组设4个重复,每个重复20只,共处理28 d.造模14、28 d,测定肝脏氧化应激、血清肝功能和内皮功能相关参数,并进行肝脏病理组织学观察.结果显示,模型组鸡肝脂含量增加、肝细胞脂肪变性,肝脏血管损伤,出现典型的鸡脂肪肝出血综合征(FLHS)病变;与对照组相比,各模型组肝脏MDA含量升高(P＜0.05),SOD和GSH-Px活性降低,血浆AngⅡ含量增加,血清NO含量降低;相关性分析显示,肝脏脂肪变性程度与肝脏MDA含量正相关(P＜0.01),与肝脏SOD和GSH Px活性呈负相关(P＜0.01);肝脏MDA含量与肝出血分数和血浆AngⅡ含量皆有极显著的相关性(P＜0.01);肝脏SOD和GSH-Px活性与肝出血分数呈负相关(P＜0.01或P＜0.05),与血清NO含量的变化均呈正相关(P＜0.05);血浆AngⅡ含量与肝出血分数呈正相关(P＜0.05).结果表明,FLHS发生和发展过程中氧化应激参与了内皮功能紊乱的形成,血管损伤可能与氧化应激和内皮功能失调有关.     

Epidemiological study on Mycoplasma synoviae infection in layers

Mycoplasma synoviae infection occurs worldwide in commercial poultry flocks and may result in severe economic losses. The prevalence of this mycoplasma in standard layers older than 60 weeks was studied in a French department and the characteristics of infected or free flocks were compared. The genomic profiles of isolates from 36 infected flocks were studied by pulsed-field gel electrophoresis and random amplified polymorphic DNA methods in order to investigate possible routes of transmission. The minimum inhibitory concentrations of antibiotics were determined. Results showed that infection was more frequent in multi-age farms. Egg production and mortality of infected flocks were respectively lower and higher than in non-infected flocks but the differences were not statistically significant. The genomic profiles of isolates were quite homogeneous, a feature which does not facilitate the understanding of routes of transmission. All isolates were susceptible to tetracyclines, macrolides (except erythromycin), spectinomycin and fluoroquinolones.     

蛋鸡脂肪肝综合征诱因及其营养调控措施

蛋鸡脂肪肝综合征是一种营养代谢疾病,多发于产蛋高峰期蛋鸡.本文综述了诱发蛋鸡脂肪肝综合征的主要因素及降低蛋鸡脂肪肝的营养调控措施.     

Protection and immunity in commercial chicken layers administered Mycoplasma gallisepticum liposomal bacterins

Six liposomal Mycoplasma gallisepticum (MG) bacterins, differing in charge and size, and two oil-emulsion vaccines (sonicated and non-sonicated) were given to white leghorns in two doses, at 13 weeks and again 1 month later. At 21 weeks of age, all chickens were challenged with a viable 20-hour culture of MG cells (17,800 colony-forming units) intratracheally and with nonviable MG organisms (0.09 mg protein) injected subcutaneously in the wattle center. The three chicken groups that had the lowest tracheal MG-infection rates postchallenge were those given adjuvants of small multilamellar positively charged liposomes (16.67%), large multilamellar negatively charged liposomes (16.67%), and non-sonicated oil-emulsion bacterin (37.5%). These three groups also had significant levels of antibody in sera 4 weeks after the second dose of vaccine. The group given the small multilamellar positively charged liposome also showed significant delayed-type hypersensitivity (wattle swelling) (P less than or equal to 0.05). The group given the large multilamellar negatively charged liposomes had the highest local antibody response (P less than or equal to 0.01) and was the only group that had no microscopic lesions in the trachea.     

Effects of an S6 strain of Mycoplasma gallisepticum challenge at onset of lay on digestive and reproductive tract characteristics in commercial layers

Mycoplasma gallisepticum (MG), a reproductive/respiratory pathogen in poultry, has been implicated in suboptimum egg production and decreased hatchability. Commercial layer hens raised in a controlled environment were inoculated with the S6 strain of MG at 20 wk of age. The S6 inoculation had no effect on bird weight, egg production, digestive tract weight and length, or histopathologic lesion scores, although significant differences were noted in the lengths and weights of various portions of the reproductive tract. This study shows that S6MG inoculation does not detrimentally affect layer hen performance when in the absence of environmental stressors customary to a caged layer facility.     

Immunohistochemical demonstration of Mycoplasma gallinarum and Mycoplasma gallinaceum in naturally infected hen oviducts

Using indirect immunoperoxidase (IIP), peroxidase anti-peroxidase (PAP) and avidin biotin-peroxidase complex (ABC) immunohistochemical methods, Mycoplasma gallinarum and M gallinaceum antigens were demonstrated in ethanol-fixed paraffin-embedded oviduct sections from hens the eggs from which showed suboptimal hatchability. Specific immunoperoxidase staining was detected at the mucosa in the magnum portion of the oviduct. Optimal staining was achieved by applying the ABC method, though both IIP and PAP methods can also be used for diagnosis. Isolation and identification techniques gave similar results for the species of avian mycoplasmas involved.     

鸡脂肪肝出血综合征发生过程中脂质代谢与血清甲状腺激素水平变化

探讨血清甲状腺激素水平与鸡脂肪肝出血综合征（FLHs）发生之间的关系。选用14日龄青脚麻鸡160只,按体质量随机分为对照组和FLHS组。对照组饲喂基础日粮,FLHs组饲喂高脂日粮（基础日粮＋10％牛油）的同时肌肉注射苯甲酸雌二醇（剂量为2．4mg／kg,每周3次,共3周）,试验期为28d。结果显示,试验期间,FLHS组鸡的体温明显降低;28和42日龄时,FLHS组鸡的平均体质量与平均采食量均显著高于对照组（P〈0．05或P〈10．01）;皮下脂肪厚度、肌间脂肪宽度、肝指数、肝脂率、皮脂率、腹脂率升高;血清TG、TC和LDL—C浓度均显著高于对照组（P〈0．05或P％0．01）,而血清HDL—C浓度均显著低于对照组（P〈0．01）;血清T3、T4和FT3水平降低,特别在试验后期降低更明显,而血清FT4水平变化不显著;同时FLHS组血清TP、ALB和PA浓度均比对照组有所提高。结果提示,FLHS可引起血清甲状腺激素水平的下降,而甲状腺激素水平的下降进一步造成脂质代谢紊乱,参与了鸡FLHS的发生。     

产蛋鸡脂肪肝综合征

产蛋鸡脂肪肝综合征 ( FLS)是一种复杂的代谢疾病 ,病因涉及多种因素。其特征是肝细胞中沉积大量脂肪 ,表现为脂肪肝 ,有时肝脏出血 ,鸡体肥胖 ,产蛋减少。有的病鸡因肝功能障碍或肝脏破裂而突然死亡。该病主要发生于产蛋率高或产蛋高峰期的鸡群 [1] 。本病发病率因鸡的品种、品系、日粮组成和环境等因素不同而有差异 ,通常为鸡群的 1 %～ 2 % ,有时高达 5 %～ 7%甚至 1 5 %以上。死亡率一般低于5 % ,但有时高达 2 0 %甚至 30 % [2 ,3 ] ,给养禽业造成了严重的经济损失。由于该病多散发 ,在国内尚未引起有关方面的足够重视。当肝脏出血和…     

Eggshell apex abnormalities associated with Mycoplasma synoviae infection in layers

Eggs exhibiting eggshell apex abnormalities (EAA) were evaluated for changes in shell characteristics such as strength, thickness, and ultrastructure. Mycoplasma synoviae (MS) infection was confirmed by serological assay along with isolation of MS from the trachea and oviduct. Changes in eggshell quality were shown to be statistically significant (p < 0.01). We also identified ultrastructural changes in the mammillary knob layer by Scanning Electron Microscopy. While eggs may seem to be structurally sound, ultrastructural evaluation showed that affected eggs do not regain their former quality. In our knowledge, this is the first report describing the occurrence of EAA in Korea.     

Prevalence of Mycoplasma gallisepticum and M. synoviae in commercial layers in southern and central California

The prevalence of Mycoplasma gallisepticum (MG) and M. synoviae (MS) in commercial pullet and layer flocks in Southern and Central California was estimated by testing serum and egg-yolk samples from 360 sample flocks in Southern California and 41 sample flocks in Central California. Data relating to potential risk factors associated with MG and MS infections were collected. The estimated true prevalence rate of MG was 73% in Southern California and 3% in Central California. The estimated true prevalence rate of MS was 91% in Southern California and 32% in Central California. Compared with uninfected flocks, MG-infected flocks in Southern California were significantly older and were medicated less (P less than 0.05). More managements were under a multiple-age system, more flocks had molted, more were vaccinated with F-strain, and more had concurrent infection with MS (P less than 0.05). Only one sample flock in Central California was MG-infected; none were vaccinated with F-strain. In Southern California, MS-infected flocks were older than uninfected flocks, more had molted, more were medicated, and more had concurrent infection with MG (P less than 0.05). In Central California, MS-infected flocks did not differ significantly from uninfected flocks in any factor examined; the lack of statistical significance may be due to small sample size.     

Changes in plasma lipid and glucose levels during the onset of fatty liver and kidney syndrome in chics

Plasma glucose, free fatty acid and triglyceride levels were measured during the onset of fatty liver and kidney syndrome in chicks. Intial studies indicated that behavioural and clinical changes characteristically associated with the syndrome were observed only during the 24 h preceding death. A more detailed examination of the blood changes was made on fasted birds. Typically, affected birds could be distinguished from healthy fasted birds by a hypoglycaemia which developed within 2.5 h of the removal of food, and a slightly higher and more sustained elevation of free fatty acid levels. Triglyceride values were not generally different from those found in normal birds. Although moderate to large amounts of lipid were occasionally observed in the kidneys of healthy fasted birds, only in affected birds was significant lipid infiltration of the kidneys associated with a similar level of lipid infiltration of the liver. In extreme cases death from fatty liver and kidney syndrome could occur within 4 h of the removal of food.     

Role of Mycoplasma synoviae in commercial layer Escherichia coli peritonitis syndrome

Mycoplasma synoviae (MS) is an important pathogen of domestic poultry and is prevalent in commercial layers. During the last decade Escherichia coli peritonitis became a major cause of layer mortality. The possible role of MS in the E. coli peritonitis syndrome of laying hens was studied. Four groups of 64 mycoplasma-free commercial layers at the onset of lay (about 80% daily production) were challenged with a virulent MS strain or a virulent avian E. coli strain or both. The four experimental groups were identified as follows: negative control, E. coli, MS, and MS plus E. coli. A typical E. coli peritonitis mortality was reproduced and included one, three, zero, and five birds in the negative control, E. coli, MS, and MS plus E. coli groups, respectively. Only the increased mortality in the MS plus E. coli group had statistical significance. Four weeks postchallenge 10 clinically normal birds from each of the four experimental groups were necropsied. All of the examined birds in the two MS-challenged groups demonstrated severe tracheal lesions. Body cavity lesions were detected in two and four birds in the MS and MS plus E. coli groups, respectively. The results demonstrate a possible pathogenesis mechanism of respiratory origin with regard to the layer E. coli peritonitis syndrome, show the MS pathological effect in layers, and indicate that a virulent MS strain can act as a complicating factor in the layer E. coli peritonitis syndrome.     

Improving effect of dietary soybean phospholipids supplement on hepatic and serum indexes relevant to fatty liver hemorrhagic syndrome in laying hens

In order to investigate the effect of dietary soybean phospholipid supplement on hepatic and serum indexes relevant to fatty liver hemorrhagic syndrome (FLHS) in layers, 135 300‐day‐old Hyline Brown layers were randomly divided into three groups (control, pathology and prevention), and each group had 45 layers with three replicates. Birds in the three groups were respectively fed the control diet, high‐energy low‐protein diet and high‐energy high‐protein diet affixed with 3% soybean phospholipid instead of maize. Results showed in the 30th day, birds’ livers in the pathology group became yellowish, enlarged in size and had hemorrhagic spots, while the prevention and control groups’ layers did not have such pathological changes. Contents of triglyceride, total cholesterol, low‐density lipoprotein – cholesterol, non‐esterified fatty acid and malondialdehyde in serum or liver homogenate in prevention and control groups were remarkably lower than those in the pathology group (P < 0.05 or P < 0.01), as with the activities of glutamic oxalacetic transaminase and glutamic‐pyruvic transaminase (P < 0.01); high‐density lipoprotein – cholesterol value was strikingly higher than that of the pathology group (P < 0.01). It is suggested dietary soybean phospholipids supplement may effectively improve hepatic and blood indexes relevant to FLHS, which provides a new point for preventing FLHS occurrence rate in laying flocks and treating human non‐alcohol fatty liver disease.