Pathology and histopathology of gossypol toxicity in broiler chicks

Two experiments were conducted to determine the toxicity, pathology, and histopathology of purified gossypol in broiler chicks. Gossypol was added to broiler feed at 0, 100, 200, and 400 mg/kg of feed in Experiment 1 and at 0, 800, and 1600 mg/kg of feed in Experiment 2. Day-old broiler chicks were fed these diets from 1 to 21 days in Experiment 1 and from 1 to 23 days in Experiment 2. In Experiment 1, body weight and feed intake at 21 days were not significantly affected by dietary gossypol. However, chicks fed gossypol at 400 mg/kg of feed had poor feed conversion ratio compared with the other treatment. Feed conversion ratios were 1.493, 1.564, 1.471, and 1.60 for chicks fed gossypol at 0, 100, 200, and 400 mg/kg of feed, respectively (Experiment 1). Chicks fed 400 mg/kg gossypol also had mild perivascular lymphoid aggregate formations and bilary hyperplasia in the liver. In Experiment 2, gossypol at 1600 mg/kg resulted in 28.1% mortality. Gossypol at 800 and 1600 mg/kg feed resulted in significant decreases in body weight and feed intake of chicks. The average body weights of 23-day-old chicks in Experiment 2 were 676, 224, and 111 g for 0, 800, and 1600 mg/kg gossypol, respectively. Feed conversion ratios of chicks fed 800 and 1600 mg/kg gossypol were significantly higher than those of chicks fed control diets (1.383 vs. 1.564 vs. 1.745 for 0, 800, and 1600 mg/kg gossypol, respectively). Plasma iron and hematocrit values were significantly reduced by gossypol at 800 and 1600 mg/kg of feed. Enlarged gallbladder was the only gross pathology symptom associated with gossypol levels. Severe cases of perivascular lymphoid aggregate formation, biliary hyperplasia, and hepatic cholestasis were observed in chicks fed 800 and 1600 mg/kg of gossypol in feed. No gossypol-related changes were observed in kidney tissues of chicks. These results show that gossypol is toxic to broiler chicks at high levels. This study also shows that histopathologic changes in liver due to gossypol also occur at levels lower than the levels that affect body weight.     

Pathogenesis of trichostrongylosis

Trichostrongylosis is a major cause of impaired productivity in ruminants. The pathogenesis of such infections is principally associated with inappetence and increased losses of proteins into the gastrointestinal tract. Resultant changes in host metabolism account for the poor productivity in infected animals, although the precise mechanisms require further investigation. Studies are also required to investigate in greater detail the interactions between trichostrongylosis and the nutritional and immunological status of the host.     

鹅传染性法氏囊病的诊断与处理

传染性法氏囊病是由传染性法氏囊病毒引起的一种急性、高度接触性传染病。原来仅发生于鸡，鹅、鸭不能感染发病。但近年来，我国已陆续有鹅感染传染性法氏囊病的报道。病毒分离鉴定及用法氏囊卵黄抗体治疗，效果显著，也证明鹅可以感染本病。2009年3月，我市竹泓镇西刘村李某饲养雏鹅800只，送数只病死鹅到我站门诊，初步诊断为雏鹅法氏囊病。     

鹅喹乙醇中毒的病例报告

1 发病情况 2004年7月2日,辽宁省海城市大屯镇河东村,2个养殖户共养鹅508只.数日前有的鹅出现拉稀现象,个别鹅排绿色粪便,疑为大肠杆菌感染,畜主去当地兽药店买了喹乙醇,拌料饲喂,至第2天未见好转,并出现死亡,第4天喂药300 g,死亡数量增加.畜主带死亡鹅到辽宁省动物疫病预防控制中心检验,经问诊、病理剖检,诊断为喹乙醇中毒,立即停药,但死亡还在继续,到第7天时,鹅全部死亡.     

一例鸡痘的病理学观察

一日雅安某鸡场送检10只病鸡,笔者采集病鸡的心、肝、脾、肺、肾、皮肤等器官作病理切片,进行HE染色,镜检。结果在病鸡皮肤棘皮层细胞质内观察到大量的嗜酸性包涵体。此外还对病鸡作了禽流感和鸡瘟的血清学鉴别诊断,均呈阴性反应。结合临床及病理资料,初步诊断该病例为鸡痘感染。     

Outbreaks of early-season trichostrongylosis in calves in Denmark

This paper describes clinically manifest infections occurring as early as June and early July in first-season grazing calves in Denmark during the period 1972-1987. Two severe outbreaks in 1976, included in our experiments, were studied in detail. Herbage infectivity was particularly high in grass tufts surrounding cow pats that were present in high numbers around the time of turnout. It is hypothesized that the preceding extremely dry summer followed by a hard winter had indirectly retarded degradation of dung pats and thereby favoured the overwintering of the larval populations in the dung reservoirs. In a third experiment, conducted in the same year, the epidemiological pattern was more normal; presumably due to artificial irrigation of the pasture during the drought. Early-season cases that were recorded in 1980 and 1987 could possibly be related to cold winters and/or very early turnout. The findings are discussed in the light of ecological factors responsible for the breakdown of cow pats. The clinical implications are seen in relation to current control methods.     

一例鹅爆发鸭疫里默氏杆菌病的诊断与治疗

鸭疫里默氏杆菌病又称鸭传染性浆膜炎,原名鸭疫巴氏杆菌病,主要是侵害小鸭的一种传染病,以气囊炎、心包炎、肝周炎为主要病变。该病于1904年首次被报道。我国自1982年在北京首次爆发该病以来,全国许多地区也相继报道了本病,以鸭感染为主。但随着鹅的规模化生产,鹅的饲养总数量和单位容量都出现了较大提高,大部分养殖户仍然沿袭粗放饲养方式,营养、管理、防疫等方面工作没有跟得上,致使鹅群时常经受疾病的困扰,该病也成为小鹅目前常见和严重的传染病之一。现将我们镇上一养鹅户鹅群爆发鸭疫里默氏杆菌病的诊断和治疗情况汇报如下。     

我国鹅的遗传资源与鹅业生产

我国是世界养鹅历史最早的国家之一，也是世界上饲养数量最多的国家之一，饲养量与出栏量约占世界90％左右。据历史考证，在3000多年前，我国就开始驯化养鹅，从古到今，由于我国人民一直就有养鹅、爱鹅、吃鹅的习惯，再加上我国幅员辽阔，各地自然生态条件复杂多样，不同时期的经济文化背景不同，对鹅的选择和利用目的不同，就逐步形成了20余种具有不同外貌特征、     

一例肉鹅营养性缺乏病的诊疗

我市一养鹅专业户,饲养肉鹅1500只,购进后按照程序进行免疫,预防过小鹅瘟,鹅副粘病毒、禽流感等疾病,采用塑料大棚网上饲养的方式进行饲养,用自配料,其中麦麸占15%,米糠占85%进行饲喂.     

鹅源禽Ⅰ型副黏病毒的分离与鉴定

鹅副黏病毒是鹅的一种烈性传染病,该病使10日龄以内的雏鹅发病率和病死率均达到100%,平均发病率和病死率分别为27.7%和18.2%.     

鹅细小病毒VP3基因和鹅副黏病毒F基因在重组禽痘病毒中联合表达

将重组转移载体质粒pSY681-VP3-F-LacZ与脂质体转染禽痘病毒感染的CEF细胞,通过五轮蓝斑筛选,获得纯化的重组病毒rFPV-VP3-F.经PCR检测,表明GPV-VP3基因和GPMV-F基因已重组到特异性禽痘病毒基因组中;Dot-ELISA和间接免疫荧光试验,证明VP3蛋白和F蛋白在重组病毒感染的CEF细胞中获得有效表达并且两种蛋白都保持其反应原性.     

板蓝根多糖抗小鹅瘟病毒的作用

在鹅胚内用板蓝根多糖(IRPS)作直接杀毒和阻断感染试验,对鹅胚尿囊液中小鹅瘟病毒(GPV)含量、鹅胚存活时间、存活率、病变和免疫组化进行测定。结果显示,40μg/胚IRPS阻断感染组,GPV接种后72h ELISA检测为阳性的尿囊液最高稀释倍数23;鹅胚平均存活时间192h;存活率6/6;胚体肉眼观察未见病变;切片镜检可见肝、肾轻度淤血和细胞变性,心、脑轻度淤血和水肿;免疫组化显示肝、肾内GPV表达抗原为弱阳性,心、脑内为阴性。而攻毒对照组尿囊液GPV阳性的最高稀释倍数28;鹅胚存活时间138h;存活率0/6;胚体严重萎缩、出血、水肿,各组织细胞碎裂、坏死,组织内GPV表达抗原全为强阳性。两者比较,各指标具有极显著差异。这表明在鹅胚内IR-PS具有极强的阻断GPV感染、增殖和保护胚体组织器官免受其损伤的作用。     

小鹅瘟与鹅几种常见病的鉴别诊断

小鹅瘟(Goose parvovirus,GP)又称得舍氏(Derzsy)病、小鹅病毒性肠炎、鹅细小病毒感染等,是由小鹅瘟病毒引起的一种急性或亚急性的败血性传染病.本病多发生于2～30 日龄内的雏鹅,特别是以10日龄时发病率和死亡率最高,其发病率和病死率随雏鹅日龄增大而降低.病鹅表现为食欲减退甚至废绝、精神不振、嗜睡,两腿麻痹或痉挛;肛门向外突出,周围被毛潮湿并沾有污染物,排出灰白色或者淡黄色稀粪便,常混有气泡.     

原位PCR检测雏鹅体内鹅细小病毒方法的建立及其应用

通过建立能对石蜡切片中鹅细小病毒(GPV)核酸进行定位的原位PCR方法,为GPV在鹅体内的定位、致病机理研究等提供有效的试验手段.根据GPV的VP3基因序列设计PCR引物和寡核苷酸探针,以GPV感染鹅肝脏和空肠组织石蜡标本制作切片,经蛋白酶K消化、原位PCR扩增和碱性磷酸酶标记的寡核苷酸探针原位杂交,建立了检测石蜡标本中GPV的间接原位PCR方法并应用于自然感染GPV高免血清紧急免疫后鹅肝脏和空肠组织临床病料检测.结果显示间接原位PCR对人工感染GPV死亡鹅肝脏和空肠的石蜡标本检测结果为阳性,而鹅病毒性肝炎、鹅多杀性巴氏杆菌病、鹅沙门菌病和鹅大肠杆菌病死亡鹅肝脏的石蜡标本检测结果为阴性;间接原位PCR对自然感染GPV高免血清紧急免疫后第6天的鹅肝脏和空肠组织检测20个样本中,空肠组织有8个呈阳性,肝脏组织有4个阳性结果均为阳性,阳性细胞有空肠上皮细胞、肝窦上皮细胞等.     

Effects of separate and mixed grazing on trichostrongylosis in first- and second-season grazing calves

This study on natural trichostrongylosis in calves on permanent pasture was designed to evaluate whether susceptible first-season calves would benefit from mixed grazing with second-season calves that were more resistant. The experimental plan allowed a comparison of the effect of mixed grazing with that of separate grazing for each age category. The results showed that the first-season calves already grazing with the older animals at the beginning of the grazing season had lower parasite burdens and less clinical symptoms than first-season calves grazing alone. This effect, experienced in 1987 and characterized by a rather high overwintered parasite population on herbage, could not at this early stage be explained by a parasite "diluting" effect exerted by the older animals, but might perhaps be explained by different grazing behaviour of the two age categories. Later in the summer, the first-season calves continued to benefit from the mixed grazing, most likely because the pasture was less contaminated per unit area due to the very low egg deposition of the older animals. The effect of mixed grazing was most clearly reflected in the differences between worm burdens in tracer calves grazing the respective plots at the end of the season. Apparently, the second-season calves did not suffer parasitologically from grazing together with the younger animals. The paper discusses possible long-term implications with combinations of different age categories of cattle.     

A preliminary investigation into the control of trichostrongylosis in calves in Kenya.

A series of 3 grazing experiments was carried out to collect data relevant for designing techniques to prevent trichostrongylosis in dairy calves in Kenya. In the first experiment 1 week in/5 weeks out rotation was compared with set stocking. The results indicated that rotation is not an effective control measure. In the second experiment the effects of daily removal of faeces from the field were investigated. This practice also had a limited effect in controlling nematode infection in calves. The third experiment concentrated on the influence of nutrition level. It was shown that feeding level does affect the growth rate but its effect on the course of the egg output was not clear-cut. The results also indicated that the dry season greatly reduces herbage infestation.