低温诱发肉鸡肺血管重塑过程中肺动脉平滑肌细胞c-Myc蛋白表达的变化

试验旨在研究环境低温诱发肉鸡肺血管重塑过程中肺小动脉血管平滑肌细胞c-Myc蛋白的表达变化,初步探讨肉鸡肺血管重塑的发生机制.120只雄性AA商品代肉鸡15日龄时随机分为对照组((22±1.5)℃)条件下饲养)和低温组((11±2)℃条件下饲养).15～50日龄,每周每组随机取6只,取肺组织做石蜡切片,Weigert-间苯二酚复红染色,观察并测定m管重塑情况;采用免疫组织化学方法榆测肺动脉血管平滑肌细胞c-Myc蛋白表达,并对其进行半定量化.结果显示:(1)低温组肉鸡肺小动脉结构从36日龄开始较对照组发生了明显的重塑(P<0.01或P<0.05);(2)低温组肉鸡肺小动脉血管平滑肌细胞c-Myc蛋白表达从29日龄开始较对照组明显增加(P<0.01).结果表明:低温叫显诱发了肉鸡肺小动脉平滑肌细胞c-Myc蛋白的表达,且参与了肉鸡肺血管重塑的发生发展.     

红三叶异黄酮对肉鸡血液几种内源性激素水平的影响

本试验旨在研究饲粮中添加红三叶异黄酮对肉鸡血液几种内源性激素水平的影响。选取1日龄雄性爱拔益加肉仔鸡240羽,随机分为4组(每组4个重复,每个重复15只),分别饲喂在基础饲粮中添加0(对照组)、10(试验Ⅰ组)、20(试验Ⅱ组)、30 mg/kg(试验Ⅲ组)红三叶异黄酮的试验饲粮。试验持续7周。结果表明:试验Ⅰ组和试验Ⅱ组的平均日增重显著或极显著高于对照组和试验Ⅲ组(P<0.05或P<0.01)。各试验组料重比均低于对照组,但差异不显著(P>0.05)。血清生长激素(GH)水平,试验Ⅱ组在21、35和49日龄均显著或极显著高于对照组(P<0.05或P<0.01),试验Ⅰ组在49日龄、试验Ⅲ组在21日龄显著或极显著高于对照组(P<0.05或P<0.01);血清类胰岛素生长因子Ⅰ(IGF-Ⅰ)水平,各试验组在21日龄均显著高于对照组(P<0.05),试验Ⅱ组在49日龄显著高于对照组和其他试验组(P<0.05);血清三碘甲腺原氨酸(T3)水平,试验Ⅰ组在35和49日龄、试验Ⅱ组在49日龄均显著或极显著高于对照组(P<0.05或P<0.01);血清四碘甲腺原氨酸(T4)水平,试验Ⅰ组和试验Ⅲ组在35日龄显著低于对照组(P<0.05);血清T3/T4,各试验组在21、35和49日龄均高于对照组,并且在35和49日龄试验Ⅰ组与对照组达到显著水平(P<0.05);血清睾酮(TESTO)水平,各组在21、35和49日龄均无显著差异(P>0.05)。由此得出,红三叶异黄酮可通过调节体内GH、IGF-Ⅰ、T3和T4水平来影响肉鸡的生长性能,饲粮中添加20 mg/kg时促生长效果较好。     

乳酸菌素对肉鸡血清生化指标和抗氧化功能的影响

本试验旨在探讨乳酸菌素对肉鸡血清生化指标和抗氧化功能的影响。300只1日龄肉鸡随机分为5组,每组4个重复,每个重复15只。Ⅰ组为空白对照组,饲喂基础饲粮;Ⅱ组为抗生素对照组;Ⅲ、Ⅳ、Ⅴ组分别饲喂在基础饲粮中添加50、100、200 mg/kg乳酸菌素的试验饲粮。试验期70 d,分别在肉鸡28日龄和70日龄时采样,计算料重比,并检测各组中血液生化指标和抗氧化功能各项指标。结果表明:1)与Ⅰ组比较,试验1～28 dⅡ～Ⅴ组肉鸡增重显著升高(P<0.05),料重比显著降低(P<0.05);1～70 dⅡ组和Ⅳ组肉鸡增重显著升高(P<0.05),Ⅱ～Ⅴ组料重比显著降低(P<0.05),Ⅳ组最低,显著低于其他各组(P<0.05),Ⅱ、Ⅲ、Ⅴ组之间差异不显著(P>0.05)。2)各组肉鸡血清尿素氮含量无显著差异(P>0.05)。Ⅱ～Ⅴ组28日龄肉鸡血清总胆固醇含量和70日龄肉鸡血清碱性磷酸酶活性均极显著或显著高于Ⅰ组(P<0.01或P<0.05);Ⅱ组和Ⅳ组28日龄肉鸡血清总蛋白含量均显著高于Ⅰ组(P<0.05);各组70日龄肉鸡血清总胆固醇和总蛋白含量均无显著差异(P>0.05)。Ⅱ、Ⅲ、Ⅳ、Ⅴ组之间上述各血清生化指标均差异不显著(P>0.05)。3)28日龄时,Ⅱ组和Ⅳ组肉鸡血清超氧化物歧化酶(SOD)活性均显著高于Ⅰ组和Ⅴ组(P<0.05),但与Ⅲ组差异不显著(P>0.05);Ⅱ～Ⅴ组肉鸡血清总抗氧化能力(T-AOC)均极显著高于Ⅰ组(P<0.01),但组间差异不显著(P>0.05)。70日龄时,Ⅱ～Ⅳ组肉鸡血清SOD活性和T-AOC均显著或极显著高于Ⅰ组(P<0.05或P<0.01),但组间差异不显著(P>0.05)。可见,饲粮中添加乳酸菌素可改善肉鸡生长性能,提高其抗氧化功能,以添加100 mg/kg乳酸菌素效果最佳。     

葛根素对饲喂氧化大豆油黄羽肉鸡免疫器官抗氧化功能的影响

选取1日龄健康雌性黄羽肉鸡360只,随机分成4个处理组,每个处理6个重复,每个重复15只鸡.4个处理组分别饲喂新鲜大豆油饲粮(Ⅰ组,对照组)、新鲜大豆油十葛根素(750 mg/kg)饲粮(Ⅱ组)、氧化大豆油饲粮(Ⅲ组)和氧化大豆油十葛根素(750mg/kg)饲粮(Ⅳ组).在28,56日龄时,每个重复随机选取1只鸡,断颈...     

谷氨酰胺对肉鸡小肠组织结构和吸收能力的影响

本试验旨在研究饲粮不同添加水平谷氨酰胺(Gln)对热应激肉鸡小肠组织结构和吸收能力的影响.选用1日龄科宝- 500肉鸡240只,随机分为6个处理,每个处理4个重复,每个重复10只.Ⅰ组为对照组,饲喂玉米-豆粕型基础饲粮,Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ组为试验组,分别饲喂在基础饲粮中添加0.4％、0.8％、1.2％、1.6％和2.0...     

谷氨酰胺、甘氨酰谷氨酰胺对肉鸡生长性能和肠道发育的影响

选择健康1日龄黄羽肉鸡(母)90只,随机分为3个组,每组3个重复,每重复10只。Ⅰ组为对照组,饲喂基础日粮;Ⅱ、Ⅲ组为试验组,分别饲喂在基础日粮中添加0.40%谷氨酰胺和0.20%甘氨酰谷氨酰胺的饲粮。试验期为28d。结果表明,在肉鸡日粮中添加0.40%谷氨酰胺或0.20%甘氨酰谷氨酰胺均有利于提高肉鸡早期平均日增重和饲料报酬,可促进肉鸡小肠的发育;其中,添加0.20%甘氨酰谷氨酰胺的效果优于添加0.40%谷氨酰胺。     

复合益生菌制剂对肉鸡生长性能、屠宰性能和免疫指标的影响

本试验旨在研究不同配比复合益生菌制剂对爱拨益加(AA)肉鸡生长性能、屠宰性能和免疫指标的影响。选用320只1日龄健康雄性AA肉仔鸡,随机分为4组,每组4个重复,每个重复20只鸡。对照组(Ⅰ组)饲喂基础饲粮,Ⅱ、Ⅲ和Ⅳ组饲粮分别在基础饲粮中添加1 000 mg/kg不同配比复合益生菌制剂。试验期42 d。结果表明:1)1~42日龄时,Ⅲ组肉鸡的平均日采食量和平均日增重最高,料重比最低,与Ⅰ组差异显著(P0.05)。2)Ⅲ和Ⅳ组的胸肌率显著高于Ⅰ组(P0.05)。3)21和42日龄时,Ⅲ组肉鸡的血清免疫球蛋白A含量显著高于Ⅰ组(P0.05)。由此可知,饲粮中添加复合益生菌制剂可不同程度提高肉鸡的生长性能,改善屠宰性能,提高血清免疫球蛋白含量,其中以添加1 000 mg/kg配比为1∶2∶1∶1(枯草芽孢杆菌∶酿酒酵母∶嗜酸乳杆菌∶乳双歧杆菌)的复合益生菌制剂效果最好。     

不同来源木聚糖酶及其组合对肉鸡肠道黏膜形态与二糖酶活性及其基因表达的影响

本试验旨在探讨不同来源木聚糖酶及其组合对黄羽肉鸡肠道黏膜形态、二糖酶活性及其基因表达的影响。试验选取1 560只1日龄黄羽肉公鸡,随机分为4组(每组6个重复,每个重复65只):对照组(Ⅰ组)饲喂低能量低蛋白质的基础饲粮,试验组(Ⅱ、Ⅲ和Ⅳ组)分别饲喂在基础饲粮中添加4 000 U/kg的黑曲霉来源单一木聚糖酶1#、康氏木霉来源单一木聚糖酶2#和组合型木聚糖酶(木聚糖酶1#∶木聚糖酶2#=1∶1)的饲粮,试验期63 d。每个重复分别于21、42和63日龄时取2只肉鸡采集肠道组织,用于肠道黏膜形态、二糖酶活性及二糖酶基因mRNA表达丰度的测定。结果表明:1)Ⅳ组21日龄时空肠隐窝深度显著低于Ⅰ组(P0.05);Ⅳ组42日龄时十二指肠绒毛高度/隐窝深度(V/C)值极显著大于Ⅰ组(P0.01),显著大于Ⅱ和Ⅲ组(P0.05),且Ⅳ组42日龄时空肠V/C值极显著大于Ⅰ、Ⅱ和Ⅲ组(P0.01)。2)21日龄时,十二指肠和空肠中麦芽糖酶活性以及空肠中蔗糖酶活性表现为Ⅳ组极显著高于Ⅰ、Ⅱ和Ⅲ组(P0.01);42日龄时,空肠中蔗糖酶活性表现为Ⅳ组极显著高于Ⅰ和Ⅱ组(P0.01),显著高于Ⅲ组(P0.05)。3)42日龄时,Ⅳ组空肠中麦芽糖酶-葡萄糖淀粉酶(MGA)mRNA表达丰度极显著高于Ⅰ和Ⅱ组(P0.01)。由此得出,肉鸡在前(1~21日龄)、中期(22~42日龄)阶段,木聚糖酶的添加能够改善肉鸡肠道黏膜形态,促进二糖酶的分泌及其基因表达,且组合型木聚糖酶的作用效果优于单一木聚糖酶,表现出高效催化的组合效应。     

腐植酸钠对AA肉鸡血清生化指标的影响

为了探讨腐植酸钠对AA肉鸡血清生化指标的影响,笔者将240只1日龄AA肉鸡(公母各半)随机分为4组,每组2个重复,每个重复30只。Ⅰ组为空白对照,饲喂基础日粮;Ⅱ、Ⅲ、Ⅳ组为试验处理组,饲喂基础日粮并分别添加1.0 g/kg、1.5 g/kg和2.5 g/kg的腐植酸钠。28、42日龄每个重复随机抽取6只鸡(公母各半),测定血清总蛋白、白蛋白、葡萄糖、无机磷含量,以及钾离子、镁离子、钙离子的浓度。结果表明,血清白蛋白含量28日龄时Ⅱ组极显著(P0.01)低于Ⅰ组(对照组);葡萄糖含量28日龄时Ⅲ组显著低于Ⅰ组(P0.05);无机磷含量42日龄时Ⅱ组显著低于Ⅰ组(P0.05);K+浓度28日龄时Ⅳ组显著高于Ⅰ组(P0.05),42日龄时Ⅱ组显著低于Ⅰ组(P0.05);血清Mg2+浓度28日龄时Ⅲ组、Ⅳ组极显著低于Ⅰ组(P0.01)。其余各指标各试验组与对照组间的差异均未达到显著水平(P0.05)。     

低温诱发肉鸡腹水综合征过程中肺动脉平滑肌细胞增殖的变化

本试验旨在研究低温诱发肉鸡腹水综合征(AS)过程中平滑肌细胞增殖在肺血管重塑过程中的动态变化,初步探讨肺血管重塑的机制。160只15日龄雄性AA商品代肉鸡随机分为对照组(22℃±1.5℃)和低温组(11℃±2℃)。试验持续至50日龄,期间每周每组随机取6只,取肺组织做石蜡切片,Weigert-间苯二酚复红染色,观察并测定血管重塑情况;采用免疫组织化学方法检测肺动脉增殖细胞核抗原(PCNA)蛋白表达,并对其半定量化,分析平滑肌细胞增殖情况。50日龄时统计整个饲养过程中AS发生率。结果显示:(1)低温组肉鸡AS发生率(18.75%)极显著高于对照组(1.25%)(P<0.01);(2)低温组肉鸡直径20-50μm和50-150μm肺动脉结构从36日龄开始较对照组发生了明显的重塑(P<0.01或P<0.05);(3)低温组肉鸡直径20-50μm和50-150μm的肺动脉平滑肌细胞增殖指数分别从22日龄和36日龄开始极显著高于对照组(P<0.01)。结果表明:低温诱发肉鸡AS过程中肺动脉结构发生了明显的重塑,肺动脉平滑肌细胞发生了明显的增殖,并且平滑肌细胞增殖促进了肺血管重塑,在肉鸡AS发生发展过程中起着重要的作用。     

Relationship of pulmonary arterial pressure to pulmonary haemorrhage in exercising horses

Exercise-induced pulmonary haemorrhage (EIPH) is characterised by blood in the airways after strenuous exercise and results from stress failure of the pulmonary capillaries. The purpose of this experiment was to establish a threshold value of transmural pulmonary arterial pressure at which haemorrhage occurs in the exercising horse. Five geldings, age 4-14 years, were run in random order once every 2 weeks at 1 of 4 speeds (9, 11, 13, 15 m/s); one day with no run was used as a control. Heart rate, pulmonary arterial pressure and oesophageal pressure were recorded for the duration of the run. Transmural pulmonary arterial pressure was estimated by electronic subtraction of the oesophageal pressure from the intravascular pulmonary arterial pressure. Within 1 h of the run, bronchoalveolar lavage was performed and the red and white blood cells in the fluid were quantified. Red cell counts in the lavage fluid from horses running at 9, 11 and 13 m/s were not significantly different from the control value, but after runs at 15 m/s, red cell counts were significantly (P<0.05) higher. White cell counts were not different from control values at any speed. Analysis of red cell count vs. transmural pulmonary arterial pressure indicated that haemorrhage occurs at approximately 95 mmHg. Red cell lysis in the lavage fluid was also apparent at transmural pulmonary arterial pressures above 90 mmHg. We conclude that, in the exercising horse, a pulmonary arterial pressure threshold exists above which haemorrhage occurs, and that pressure is often exceeded during high speed sprint exercise.     

Diagnosis of pulmonary hypertension

Pulmonary hypertension may complicate a variety of congenital or acquired cardiac and pulmonary conditions. This vascular disorder results from conditions that lead to a chronic increase in left atrial pressure, increased pulmonary blood flow, or increased pulmonary vascular resistance. Definitive diagnosis requires cardiac catheterization and detection of systolic and mean pulmonary artery pressures exceeding 30 and 20 mm Hg, respectively. Clinical signs and historical complaints reflect underlying cardiac or pulmonary conditions, although syncope may be a predominant finding. Radiographic changes are nonspecific; however, right ventricular enlargement and enlarged pulmonary arteries should increase suspicion for the disorder. Estimates of pulmonary arterial pressure may be obtained through Doppler echocardiography. This requires detection of a high-velocity regurgitant jet across the tricuspid or pulmonic valve. Further investigation is required to determine how pulmonary hypertension impacts therapy and prognosis for dogs and cats with cardiac and pulmonary diseases.     

Diagnosis of pulmonary thromboembolism in a cat using echocardiography and pulmonary scintigraphy

A 10-year-old male cat was presented with sudden onset of respiratory difficulties. Clinical examinatlon revealed an acute dyspnoea with cyanosis associated with a left systolic heart murmur. Standard thoracic radiographs excluded pulmonary oedema and showed very few pulmonary changes given the intensity of the respiratory compromlse. Echocardiographic examination revealed hypertrophic cardiomyopathy and a thrombus In the right pulmonary artery. Pulmonary sclntlgraphy confirmed a pulmonary thromboembolism with hypovascularisatlon of the left cranial lobe and of the ventral segment of the right lobe. Conservative treatment was instituted using an antibiotic (doxycycllne), anticoagulants (heparin, coumadine) and a calcium lnhlbitor (diltiazem). The cat was given absolute rest. The general condition of the animal improved.     

Exercise-induced pulmonary hemorrhage

This article addresses many aspects of exercise-induced pulmonary hemorrhage (EIPH). Reports of the prevalence, effect on performance, and the clinical signs and means of diagnosis of EIPH are included. Radiologic and scintigraphic findings in horses with EIPH are reported. Pathogenesis and treatment are discussed.