缺氧、肺动脉高压、心脏功能与肉鸡腹水综合征的关系

为阐明缺氧、肺动脉高压、心脏功能与肉鸡腹水综合征 (ascites syndrome,AS)之间的关系 ,比较了正常肉鸡、亚临床腹水鸡和腹水鸡的右心室平均压 (m RVP)、平均肺动脉压 (m PAP)、心电图 导联 S波幅 (L ead S)、红细胞压积(HCT)、动脉血血氧饱和度 (Sa O2 )、心率 (HR)和右心肥大指数 (RV/ TV) ,并对这些指标进行相关分析和回归分析。结果表明 :在 AS的发展过程中 ,m RVP、m PAP、L ead S、HCT和 RV/ TV逐渐升高 ,HR和 Sa O2 逐渐下降 ;各指标相互之间的相关性都很高 (P<0 .0 0 1) ;HCT发生变化较其他指标早。此外 ,亚临床腹水鸡的左心室和体质量的比值 (L V/BW)及全心室和体质量的比值 (TV/ BW)最高 ,与腹水鸡的 L V/ BW值差异显著 (P<0 .0 5 ) ;正常鸡的 TV/ BW最低 ,与亚临床腹水鸡的差异显著 (P<0 .0 5 )。结果说明肺动脉压升高与机体慢性缺氧有关 ,且是造成右心肥大衰竭和 AS的原因 ;AS发展早期肉鸡心脏功能是代偿性增加的 ;m RVP、m PAP、L ead S、HCT和 Sa O2 可作为早期诊断、预测AS的指标。     

肉鸡肺动脉高压综合征抗病育种研究

为了研究肉鸡肺动脉高压综合征(PHS)的抗病育种情况,试验采用静脉注射纤维素颗粒的方法诱发PHS,比较发病前后非易感组肉鸡和易感组肉鸡右心室与全心室重量比(RV/TV)值,心电图Ⅱ导联S波、R波和RS综合波波幅,红细胞比容(PCV),血红蛋白(HB)和血清蛋白含量。结果表明:静脉注射纤维素颗粒明显提高了肉鸡PHS的发病率。发病后腹水组肉鸡PCV、HB含量和RV/TV值升高,血清蛋白含量降低,心电图Ⅱ导联S波、R波和RS综合波波幅均升高,符合肉鸡PHS的特点;但发病前易感组肉鸡与非易感组肉鸡相比,PCV、HB含量、血清蛋白含量和心电图Ⅱ导联S波、R波和RS综合波波幅均无显著差异。     

早期限饲对肉鸡体内脂质过氧化作用和抗氧化酶活性的影响

采用低温诱发肉鸡腹水综合征(AS)，并观察早期限饲对常温和低温饲养时肉鸡AS的发病率、肉鸡体内脂质过氧化作用和抗氧化酶活性的影响。试验1，限饲处理组肉鸡分别于7～14日龄或7～21日龄每天给料8h，对照组肉鸡全程自由采食。试验2，限饲组肉鸡分别于7～14日龄给予对照组肉鸡前一天饲料消耗量的60％或80％，对照组肉鸡自由采食。试验过程中连续测定肉鸡血浆超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH—Px)、丙二醛(MDA)水平和腹水心脏指数(RV／TV值)。结果显示低温显著升高了肉鸡血浆MDA浓度，降低了血浆SOD和GSH—Px的活性；低温饲养肉鸡5～6周龄时的RV／TV值显著升高，AS的发病率显著增加。限饲处理显著降低了肉鸡血浆MDA含量，并且限饲处理肉鸡生长后期血浆中SOD和GSH—Px活性显著高于自由采食组肉鸡。所有的限饲处理均能降低肉鸡AS的发病率，并且早期限饲处理肉鸡42日龄的RV／TV值显著低于非限饲肉鸡。这表明早期限饲能够减轻肉鸡体内脂质过氧化作用，提高机体抗氧化酶的活性，从而降低AS的发病率。     

静脉注射纤维素微粒诱发肉鸡腹水综合征模型的建立

通过翅静脉注射CM-32纤维素微粒,观察血清白蛋白(ALB)、总蛋白(TP)、血细胞压积(PCV)、血红蛋白(Hb)、腹水等方面的变化,探讨建立肉鸡腹水综合征(AS)模型的可行性。试验分为2组,试验组在20日龄时注射0.3 mL纤维素悬液,对照组注射等量生理盐水。饲养期间统计临床型AS的发病率,并分别于21、28、35、42日龄从各组随机抽样,测定右心/全心重量比值(RV/TV),检查ALB、TP、PCV、Hb、腹水液等。结果试验组AS发病率(12%)显著高于对照组(3.3%),RV/TV值显著增加。纤维素微粒阻塞在肺血管,引起明显的炎性细胞聚集和肉芽结缔组织增生。试验组血清ALB、TP在42日龄明显低于对照组,PCV在28、35日龄时显著高于对照组(P<0.05),Hb在35日龄时显著高于对照组(P<0.05),其腹水液为典型的漏出液,表明翅静脉注射CM-32纤维素微粒成功诱发了AS。     

环境低温和T3致肉鸡腹水、肺动脉高压和肺微细动脉肌型化

21 0羽 AA商品肉鸡随机分为 A、B、C 3个组 ,常规饲养。 1 4日龄后 A组鸡正常对照 ,而 B、C组鸡舍温按每日1～ 2℃由 2 5℃逐步降至 1 2℃ ,同时 C组在日粮中按 1 .5 mg/ kg的剂量添加甲状腺素 T3以诱发肉鸡腹水综合征 ( as-cites syndrom e,AS)。结果表明 :低温和 T3能显著增加 AS发病率、红细胞压积 ( PCV)值、右心室与全心室重量比( RV/ TV)、平均肺动脉压 ( m PAP)和厚壁末梢血管百分率 ( TWPV % ) ( P<0 .0 1 )。从而揭示了环境低温和 T3诱发的AS患鸡已发生了肺动脉高压和肺微细血管肌型化     

低温致肉鸡腹水综合征及用L-精氨酸的预防

40 0只 1日龄 AA肉鸡 ,14日龄时保优淘弱 ,随机分群 ,其中 10 0只为正常温度 (2 0℃ )对照组 ,15 0只为低温(11℃ )试验组 ,10 0只为低温 (11℃ )试验鸡日粮添加 1%L -精氨酸组 ,用单因子低温诱发肉鸡腹水综合征 ,于不同时间分别用红细胞压积、心脏指数、腹水和心电图的各导联波幅变化判定肉鸡腹水综合征。结果表明 :环境温度为 11℃时 ,低温试验组肉鸡复制出腹水综合征模型 ,腹水综合征发生率为 9.33%、心脏指数 (RV/ TV)为 15 .3%(>0 .2 5 )、红细胞压积 (PCV)为 2 1.33%(>36 %)、心电图 导联 S波振幅为 0 .39m V和净增重为 0 .0 9kg,均显著地高 (低 )于正常对照组 (3%、4%、10 %、0 .0 8m V、0 .5 2 kg) (P<0 .0 1)。日粮添加 1%L-精氨酸的低温试验肉鸡腹水综合征发生率为 3%、心脏指数为 9%、PCV为 12 %、心电图 导联 S波振幅为 0 .17m V、净增重为 0 .5 2 kg,与低温试验组比较 ,差异显著 (P<0 .0 1) ;与对照组比较 ,差异不显著 (P>0 .0 5 ) ,说明 L -精氨酸能够增加肉鸡体重、降低腹水综合征的发生。     

中药对腹水症肉鸡血液理化指标的影响

肉鸡腹水症是临床上以腹水为主的循环、呼吸系统发生障碍综合征 ,发病集中于 4～ 5周龄 ,发病率高达 85 % ,死亡率为 0 %～ 30 %。肉鸡腹水症造成的经济损失巨大 ,成为影响肉鸡业发展的主要疾病之一。不少兽医工作者在防治本病上做了大量工作 ,但未有利用祖国医学研究肉鸡腹水症血液理化指标及心包液、腹水量变化方面的报道。我们根据肉鸡腹水症的发病机理和中医理论筛选中药治疗本病 ,取得较好效果。现报道如下。1　材料与方法1 .1　试验动物　经临床检查 ,A超探测 ,确诊 30日龄患腹水症的艾维茵肉鸡 1 0 0只 ,另选 5 0只 30日龄健康肉鸡…     

A超对肉鸡腹水征的诊断

本研究探讨了用A超诊断肉鸡腹水征的方法，比较了正常与腹水鸡的红细胞压积，右心／全心的比值。结果发现与正常肉鸡相比，腹水鸡红细胞压积增高，右心；全心比值升高，液性平段增宽，A超对腹水的检出率与实际腹水的发生完全相符。提示A超可用于肉鸡腹水征的诊断。     

肉鸡腹水症

结合国内外一些文献，对肉鸡腹水症的病因，发生及经济损失。临床症状，剖检及病理组织学变化进行了综述，扼要介绍了国外用肉鸡限饲技术预防肉鸡腹水症和猝死症的方法。并简单指出在青海省海拔高度接近２３００ｍ的地区，通过改善饲养管理方法，也能有效地预防肉鸡腹水症的发生。     

中药对腹水症肉鸡心肝肺干湿重的影响

经确诊30日龄患腹水综合症的艾维茵肉鸡100只,随机分为2组;另选50只30日龄健康肉鸡为Ⅲ组,作正常对照。I组为喂中药组,Ⅱ组、Ⅲ组为未喂中药组。喂药后第5d,I组的肝干湿比值与Ⅱ组相比有极显著差异性(P<0.01);右心重量(RV)、右心重量与全心重量比(RV/TV)、心肺干湿比值比Ⅱ组低,有显著差异性(P<0.05);与Ⅲ组相比,差异不显著(P>0.05)。试验表明,本方剂能够缓解机体组织的瘀血水肿,改善机体血液循环障碍。     

Generation of hydroxyl radicals during ascites experimentally induced in broilers

Increased metabolic rates, pulmonary hypertension and cardiac dysfunction are the most important features of the ascites syndrome in broiler chickens. However, the mechanism of cell injury causing the pathogenesis of the syndrome is not clearly understood. Our study aimed to examine the generation of hydroxyl radicals (OH*) in broiler chickens experiencing ascites. The hundred and fifty 1-d-old chickens were purchased from a local hatchery and reared in an open poultry house for 46 d. They were divided at random into three groups and ascites was induced in two groups by exposing them to low temperature or administration of triiodothyronine (T(3)). The third group served as control and was reared normally. Haematological, biochemical and pathological tests were used to determine the incidence of ascites: including total red blood cell (RBC), packed cell volume (PCV), release of alanine transaminase (ALT) and aspartate transaminase (AST) and ratio of right ventricular weight to total ventricular weight (RV/TV). A salicylate hydroxylation method was used to examine the generation of hydroxyl radicals (OH*) in treated groups. TWo hydroxylated salicylic acid metabolites, 2,3- and 2,5-dihydroxy benzoic acid (2,3- and 2,5-DHBA), were measured by HPLC to detect the generation of OH*. An ascites syndrome was observed in T(3) and low-temperature treated groups, as shown by necropsy changes and increases in f RBC, PCV, ALT, AST and the ratio of RV/TV. Concentrations of 2,3- and 2,5-DHBA were increased in groups experiencing ascites compared to control group. It is suggested that reactive oxygen species that is OH* ions, may be involved in the pathogenesis of the ascites syndrome in broiler chickens.     

Activation of PKCalpha and pulmonary vascular remodelling in broilers

OBJECTIVE: The present study was conducted to examine the presence of protein kinase Calpha (PKCalpha) in the pulmonary arterioles of broilers during the development of pulmonary hypertension and pulmonary vascular remodelling. METHOD: One hundred and sixty day-old Avian-2000 broilers were divided equally into a control group and a cold temperature group. All the birds were reared in normal temperatures up to day 14, with the lighting schedule at 24 h per day. Thereafter, birds in the cold temperature group were subjected to low temperature by lowering 1-2 degrees C per day to 12-14 degrees C, and then kept constant until day 49, while birds in the control group were still brooded at normal temperatures. All the birds were fed a diet of pellets throughout the study. Samples of blood were taken from the wing vein, and of heart and lung collected after the birds were killed with an overdose of sodium pentobarbitial, at days 24, 32, 39 and 45 of age, respectively. Right ventricle to total ventricle ratio (RV/TV) and packed cell volume (PCV) were measured. Vessel wall area to vessel total area ratio (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA) was examined using computer-image analytic software. Expression of PKC in pulmonary muscular arterioles was assessed by immunohistochemistry and quantified by measuring optical density (OD) using computer-image analytic software. RESULTS: The incidence of pulmonary hypertension syndrome (PHS) was 12.5% in birds exposed to cold, and 3.75% in the control group (P<0.05). PCV in the cold temperature group was elevated after day 32 (P<0.05), and RV/TV ratio increased on day 45 (P<0.05). Both the WA/TA and mMTPA of birds subjected to cold were significantly elevated (P<0.05). The OD values were not significantly increased before day 32 (P>0.05), however, one week later (at day 39 of age), the difference between the two groups was significant (P<0.05). The increased PKCalpha expression was positively correlated with the values of mMTPA and WA/TA. CONCLUSION: PKCalpha expression was up-regulated during the development of pulmonary hypertension. The activation of PKCalpha might be involved in the development of pulmonary vascular remodelling.     

The effects of dietary flax oil and antioxidants on ascites and pulmonary hypertension in broilers using a low temperature model

1. Three experiments were conducted using a low temperature model to induce pulmonary hypertension (PH) and ascites in broiler chickens. Diets containing 25 g or 50 g flax oil/kg food and control diets with an equivalent amount of animal/vegetable (A/V) blend oil, with and without supplemental antioxidants (vitamin C and vitamin E) were used. The amount of PH was assessed by the ratio of right ventricle weight to total ventricle weight (RV/TV ratio). Birds were considered to suffer from pulmonary hypertension syndrome (PHS) if the RV/TV ratio was greater than 0.299. 2. In experiment 1, the test diets contained 50 g oil/kg food and were given during the grower period only. Birds fed on the flax oil diet tended to have a lower incidence of PHS, ascites and lower RV/TV ratios than birds fed on the control diet. However, when the flax oil diet was supplemented with antioxidants, the incidence of ascites, PHS, haematocrit and whole blood and plasma viscosity increased compared with birds fed on the flax oil diet without antioxidants. These effects were not seen in experiment 2, when the test diets containing 30 g oil/kg food (25 g flax oil plus 5 g A/V blend oil/kg food compared to 30 g A/V blend oil/kg food) were given during the grower period. However, in experiment 3, when the test diets containing 30 g oil/kg food were given from day 1 to week 8, birds fed on the control diet supplemented with antioxidants had a higher incidence of PHS than those fed on the control diet alone. 3. In all 3 experiments, there was no significant effect of dietary fat source or supplemental antioxidants on total food intake or food conversion. 4. We conclude that diets containing 50 g flax oil/kg food tend to reduce the incidence of PHS and ascites in broilers using a low temperature model but the results were not statistically significant. In some cases, supplementing diets with a combination of vitamin E and vitamin C increased the incidence of ascites and PHS.     

日粮中添加L—NAME对肉鸡腹水综合征发生的影响及其机理

应用低温环境和日粮中添加三碘甲腺原氨酸（3，3，5－triiodothyronine,T3)诱发肉鸡腹水综合征，同时通过日粮添加一氧化氮合酶抑制剂L－NAME，研究了抑制NO的合成对肉鸡肺动脉压及肉鸡腹水综合征发生的影响。180羽AA肉鸡随机等分为对照组（C）、试验组（A、B），参试鸡14日前按常规条件饲养。14日龄后C组鸡按常规条件饲养，A、B组鸡舍温按每日1－2℃逐步降至12℃，同时日粮中添加T3 1．5mg/kg以诱发腹水综合征。另外，B组肉鸡从14日龄起在日粮中添加100mg/kgL－NAME至试验结束。分别于3、4、5、6周龄测定各组肉鸡肺动脉平均压（mean pulmonary arterial pressure,mPAP)、红细胞压积、右心全心比、血浆一氧化氮（NO）和内皮素（endothelin-1,ET-1)水平并记录腹水综合征发病率。结果显示：低温添加T3处理后，A、B组肉鸡腹水综合征发病率增加，但B组高于A组；A、B组肉鸡mPAP从5周龄起高于C组（P＜0．05）；A、B组右心全心比的升高分别在6、5周龄时出现，B组右心全心比的升高比A组提前1周；B组 肉鸡血浆NO水平低于A组，差异不显著；A、B组肉鸡血浆ET－1水平高于C组（P＜0．05）；在6周龄时，A组肉鸡心率明显降低，B组肉鸡心率明显升高。随着肺动脉高压和右心肥大的出现，心率的升高可能促进了右心衰竭和肉鸡腹水综合征的发生。上述结果提示，抑制NO的合成可能促进了肉鸡肺动脉高压，右心肥大的形成和肉鸡腹水综合征的发生。     

Expression of PDGF-β receptor in broilers with pulmonary hypertension induced by cold temperature and its association with pulmonary vascular remodeling

Objective

The purpose of the present study was to characterize the relationship between platelet-derived growth factor β receptor (PDGF-β receptor) expression and pulmonary vascular remodeling found in broilers subjected to cold temperature beginning at 14 days of age.

Method

One hundred and sixty-one-day-old mixed-sex Avian-2000 commercial broilers were randomly divided into a normal temperature group (control) and a cold temperature group (cold). All the birds were brooded in normal temperature up to day 14, with the lighting schedule at 24 h per day. Starting at day 14, birds in the cold group were moved to a pen in the cold house and subjected to low temperature, while birds in the control group were still brooded at normal temperature. On days 14, 23, 30, 37 and 44, the right/total ventricle weight ratio (RV/TV), packed cell volume (PCV), the vessel wall area to vessel total area ratio (WA/TA), mean media thickness in pulmonary arterioles (mMTPA) and the expression of PDGF-β receptor in pulmonary arterioles were measured, respectively. Cumulative pulmonary hypertension syndrome (PHS) morbidity was recorded in each group.

Results

Cool ambient temperature increased PHS morbidity of broilers. The values of WA/TA and mMTPA were also increased significantly compared with control group. PCV values in the cold temperature group were elevated from days 30 to 44, and RV/TV ratios were increased on days 37 and 44. Cold exposure enhanced PDGF-β receptor expression in pulmonary arterioles, and the PDGF-β receptor expression was significantly correlated with pulmonary vascular remodeling that was dedicated by increased WA/TA and mMTPA.

Conclusion

The results indicated that PDGF-β and its receptor were involved in the underlying mechanisms of pulmonary vascular remodeling in pulmonary hypertensive broilers.     

Genetic parameters of ascites-related traits in broilers: correlations with feed efficiency and carcase traits

(1) Pulmonary hypertension syndrome followed by ascites is a metabolic disorder in broilers that occurs more often in fast-growing birds and at cool temperatures. (2) Knowledge of the genetic relationships among ascites-related traits and performance traits like carcase traits or feed efficiency traits is required to design breeding programmes that aim to improve the degree of resistance to ascites syndrome as well as production traits. The objective of this study was to estimate these genetic correlations. (3) Three different experiments were set up to measure ascites-related traits (4202 birds), feed efficiency traits (2166 birds) and carcase traits (2036 birds). The birds in different experiments originated from the same group of parents, which enabled the estimation of genetic correlations among different traits. (4) The genetic correlation of body weight (BW) measured under normal conditions and in the carcase experiment with the ascites indicator trait of right ventricle to total ventricle ratio (RV:TV) measured under cold conditions was 0.30. The estimated genetic correlation indicated that single-trait selecting for BW leads to an increase in occurrence of the ascites syndrome but that there are realistic opportunities of multi-trait selection of birds for improved BW and resistance to ascites. (5) Weak but positive genetic relationships were found between feed efficiency and ascites-related traits suggesting that more efficient birds tend to be slightly more susceptible to ascites. (6) The relatively low genetic correlation between BW measured in the carcase or in the feed efficiency experiments and BW measured in the ascites experiment (0.49) showed considerable genotype by environment interaction. (7) These results indicate that birds with high genetic potential for growth rate under normal temperature conditions have lower growth rate under cold-stress conditions due to ascites.     

Importance of Escherichia coli infection in ascites in broiler chickens shown by experimental production

Common commercial strain male broilers aged 14 days were intratracheally inoculated with 0.2 ml of 1.2 x 10(6) colony-forming units of Escherichia coli in nutrient broth and kept in a cool environment during the experiment. Ascites was produced in five surviving and two dead birds out of 50 but not in 50 mock-infected control birds. Among the 40 survivors that were infected, the erythrocyte packed cell volume (PCV) of the 10 birds with pericarditis was the same as in 21 grossly normal birds, although that of the four birds with enlarged right ventricle (RV) was high. The pericarditis caused by E. coli septicemia was not the primary cause of ascites. However, the PCV was high in some of the survivors with an enlarged RV without pericarditis, indicating overload due to the lung lesion. These data suggested that some of the birds with an enlarged RV, caused by supplying blood that was insufficiently oxygenated for the body size, suffered from ascites.     

中药防制肉鸡腹水综合征的初步研究

试验肉鸡分为5组,一组于常规温度下饲养,为正常对照组;其余4组以低温饲养诱发腹水综合征,其中一组不给任何药物,作为模型对照组,其它3组作为试验组,给予真武汤、姜术汤和苓桂术甘汤制剂.结果显示,低温饲养能明显提高肉鸡腹水发病率,真武汤和苓桂术甘汤的两个试验组腹水发病率明显低于模型对照组.腹水心脏指数及红细胞压积、红细胞数、血红蛋白含量指标显示,三个处方均能不同程度地改善腹水心脏指数及血液学参数,真武汤优于其它两个处方.