Comparison of the pathogensis of two isolates of <Emphasis Type="Italic">Besnoitia caprae</Emphasis> in inbred BALB/c mice

This study was performed to evaluate the infectivity of bradyzoites of two Besnoitia caprae isolates, BC-1 and BC-2, to inbred BALB/c mice. Each group of inbred BALB/c mice was inoculated intraperitoneally with 1 × 10³, 1 × 10⁴, 1 × 10⁵, 5 × 10⁵ and 1 × 10⁶ of one of the two isolates of B. caprae bradyzoites. The mice were monitored daily for a period of 40 days for survival. After death of each mice, several passages from its peritoneal washing and tissues were analyzed using ribosomal DNA-specific PCR assay. Marked differences in pathogenicity between the isolates were seen. All the inbred BALB/c mice infected with BC-2 survived but all the mice that were administered with 1 × 0⁵, 5 × 10⁵ and 1 × 10⁶ BC-1 bradyzoites were died within 4–9 days post-infection (DPI). Histopathological examination of the tissues of the dead mice revealed hyperemia and necrosis with presence of mononuclear and polymorphonuclear cell infiltration in myocardium, spleen and intestines together with interstitial pneumonia and peritonitis. All inbred BALB/c mice in the 1 × 10³ and 1 × 10⁴ groups of BC-1 inoculated mice survived and they were euthanized after 40 DPI. Chronic inflammation with infiltration of mononuclear cells was evident in myocardium, spleen, alveolar septa of the lungs of most of the examined tissues with hemorrhagic enteritis in the mice infected with 1x10⁶ bradyzoites. The mice infected with different doses of BC-2 were euthanized after 40 DPI and no lesion was seen in histopathological sections of their organs. All peritoneal washings and examined tissues were PCR positive in BC-1 group. This experiment is the first report to show inbred BALB/c mice as a relevant model for B. caprae and demonstrates that this strain of inbred BALB/c mice is a suitable animal model for biological studies and examination of pathogenesis for this species of Besnoitia. The present findings also provide evidence for significant differences between the two isolates of B. caprae.     

The effect of a single intramammary infusion of a biological response modifier in cows at drying off

Biological response modifiers (BRM) are compounds that interact with the immune system to regulate specific aspects of host response. The objective of this study was to describe clinical and morphological changes during involution of bovine mammary gland following a single-dose infusion of a BRM containing lipopolysaccharide and cellular fractions of Escherichia coli incorporated into liposomes. A massive leukocyte response and increased subepithelial stroma infiltration of mononuclear cells, eosinophils and mast cells was observed in BRM-treated quarters compared with untreated controls; however, morphologic parameters assessed at 11 days post infusion were indicative of only slightly accelerated involution compared with untreated controls. In addition, BRM infusion at the end of lactation did not interfere with mammary epithelial cell proliferation and caused only mild systemic effects.     

如何减少畜禽强制免疫副反应的发生

免疫副反应客观存在,一定程度成为阻碍免疫工作顺利进行的"绊脚石"。我们深入调研,通过狠抓疫苗管理,规范免疫操作,增强畜禽体质,提高人员素质等措施,为有效减少免疫副反应的发生发挥了积极作用。     

Effects of road transportation on metabolic and immunological responses in Holstein heifers

This study examined the effects of road transportation on metabolic and immunological responses in dairy heifers. Twenty Holstein heifers in early pregnancy were divided into non‐transported (NT; n = 7) and transported (T; n = 13) groups. Blood was collected before transportation (BT), immediately after transportation for 100 km (T1) and 200 km (T2), and 24 h after transportation (AT). The T heifers had higher (P < 0.05) blood cortisol and non‐esterified fatty acid concentrations after T1 and T2 than did NT heifers. By contrast, the T heifers had lower (P < 0.05) serum triglyceride concentrations after T1 and T2 than had the NT heifers. The serum cortisol and triglyceride concentrations returned (P > 0.05) to the BT concentrations at 24 h AT in the T heifers. The granulocyte‐to‐lymphocyte ratio and the percentage of monocytes were higher (P < 0.05) after T2 in the T heifers than in the NT heifers, suggesting that transportation stress increased the numbers of innate immune cells. T heifers had higher (P < 0.01) plasma haptoglobin concentrations than NT heifers 24 h AT. In conclusion, transportation increased cortisol secretion and was correlated with increased metabolic responses and up‐regulation of peripheral innate immune cells in dairy heifers.     

合生素对肉鸭生产性能及胴体品质的影响

选用1日龄健康樱桃谷肉鸭新生雏144只,按体质量随机分为3组,每组设3个重复,每重复16只。对照组饲喂基础日粮,抗生素组添加5mg／kg黄霉素基础日粮,试验组1和组2在基础日粮中分别添加0．05％和0．10％合生素。结果表明,日粮中添加合生素对肉鸭日增质量、胸肌率和腿肌率有显著影响;对肉鸭的饲料转化率有极显著影响;对肉鸭的成活率、屠宰率和皮脂率无显著影响。与抗生素组相比,具有相似的作用。试验组1的日增质量比对照组提高8．56％,比试验组2提高5．54％,比抗生素组提高4．34％;试验组1的料肉比与对照组降低11．52％,比试验组2降低3．29％,比抗生素组降低3．24％。     

重要营养素--血红素铁

血红素铁是卟啉类化合物,是哺乳动物血液中的天然色素和生物铁,广泛应用于医药、食品和化工业。文章就血红素铁的理化特性、生理功能及应用进行了简述,并对其常用提取方法进行了比较概述。     

建设生态奶源基地,促进奶业持续发展

生态奶业是指为适应社会进步和满足人们对牛奶营养卫生及环保需求，应用生态工艺实现奶业高产、优质，在奶业经济增长过程中达到环境保护，实现可持续发展的一种现代化生产模式。具体说来，就是加强对秸秆、粪尿等有机废弃物的利用，采用生物技术提高生物质能的转化率，利用生物防治和营养调控技术提高奶牛健康水平，减少有害物质的排放，生产出绿色牛奶和无污染能源。它代表了我国奶业的发展方向．也是中国奶业具备国际竞争力的重要体现。     

粗料日粮下添加苹果酸对内蒙古白绒山羊瘤胃TVFA浓度的影响

选用4头带有瘤胃瘘管的内蒙古白绒山羊作为瘤胃液供体羊,以两种不同精粗比的粗料型日粮为培养底物,研究不同苹果酸添加量(0、3、6、9、12mmol/l)对内蒙古白绒山羊瘤胃挥发性脂肪酸动态变化的影响。结果表明:不同精粗比日粮下乙酸、丙酸、丁酸及TVFA浓度均以3:7日粮组较高,乙丙比以2:8日粮组较高,差异均不显著(P>0.05)。添加苹果酸后,3:7日粮组乙酸、丙酸浓度在培养4、8、18和24h后显著升高(P<0.05);丁酸浓度3mmol/l组高于对照组,9mmol/l组低于对照组,差异均不显著(P>0.05);而2:8日粮组乙酸、丙酸浓度在培养8、18h后显著升高(P<0.05);丁酸浓度在培养8、12和24h后升高,但差异不显著(P>0.05);乙丙比在两种日粮下均极显著降低(P<0.01);TVFA浓度在两种日粮下均升高,培养4、8、18h差异是显著的(P<0.05)。     

防控人兽共患病,关注食品安全与人类健康

<正>中国畜牧兽医学会家畜传染病分会第十二次人兽共患病学术研讨会暨第六届第十四次教学委员会论坛在长春举行盛夏长春,天高云淡,伦敦奥运,拼金夺银。2012年8月7日,由中国畜牧兽医学会家畜传染病学分会主办,解放军军事医学科学院军事兽医研究所、南京农业大学、吉林省畜牧业管理局承办,吉林农业     

如何检疫上市白条鸡

在上市白条 鸡中，经常碰到 掺杂的病死鸡、 注水鸡，如何检 验，现介绍如下： １看皮肤看 翅膀内侧，健康 鸡宰后毛孔闭 合，脱毛干净，皮 肤完整，平滑细 腻，色泽鲜艳，粉 红色或白色，有 光泽，有弹性，翅 内侧血管不显露；如脱毛不净，皮肤破损，呈紫红色而无光泽，毛囊出血，翅内血管显露清晰，则是死鸡或急宰放血不良的病死鸡。２看放血刀口正常宰杀鸡喉部放血不整齐，血液侵染较深；如无放血刀口或有刀口其切面平直，又无血液浸染，是死鸡或死后又拉一刀。３看头部健康鸡宰后鸡头洁净，鸡冠和肉髯呈玫瑰色，眼有光泽微闭合，若鸡头…