Prostaglandin Release at Dexamethasone Induced Parturitions in Cows

Three cows of the Swedish Red and White Breed (SRB) were used in the experiment. Cow no. 1 pregnant for 247 days, was given 20 mg dexamethasone twice with an interval of 48 hrs. Cows nos. 2 and 3, each pregnant for 254 days, received 20 mg of dexamethasone twice with an interval of 24 hrs. The cows delivered normal living calves 153, 138 and 137 hrs., respectively, after the second injection of dexamethasone. Blood samples were drawn from the jugular vein every third hour during the experimental period and the samples were analyzed for estrone, progesterone and 15-keto-13,14-dihydroprostaglandin F₂α. Following the dexamethasone injections there was a continuous increase in the blood plasma levels of estrone followed by a sharp decrease in conjunction with parturition. The blood plasma level of progesterone showed a slow but continuous decrease until about 24 hrs. before delivery when a marked drop occurred. The levels of the prostaglandin metabolite increased gradually until about 24 hrs. prior to delivery. This was followed by an abrupt rise, and high levels of the prostaglandin metabolite were recorded for up to four days following parturition. It is concluded that the estrone increase preceded that of the prostaglandin metabolite and that the final drop in the progesterone was synchronous with the final rise of the prostaglandin metabolite level.     

The Effect of Dexamethasone on Some Immunological Parameters in Cattle

Immunosuppression as a consequence of acute and chronic stress can increase the susceptibility of cattle to a range of infectious diseases. In order to develop a panel of immune function assays for investigating the effects of potential stressors on immune competence in cattle, the effect of treatment with short- and long-acting preparations of the synthetic glucocorticoid dexamethasone was examined. Short-acting dexamethasone (dexamethasone sodium phosphate 0.08 mg/kg) followed 37 h later by long-acting dexamethasone (dexamethasone-21 isonicotinate 0.25 mg/kg) was injected intramuscularly and blood was collected to assess immune functions at intervals over the subsequent 11 days from 6 treated and 6 control Hereford steers. Dexamethasone induced leukocytosis (neutrophilia, eosinopenia, lymphopenia, monocytosis), an increased neutrophil:lymphocyte ratio, an elevated percentage of CD4⁺ lymphocytes, a decreased total CD8⁺ lymphocyte count, decreased total and percentage WC1⁺ lymphocytes, an elevated percentage of IL-2 receptor alpha (IL-2R)⁺ lymphocytes, and an elevated percentage of B lymphocytes. In vitro chemotaxis of peripheral blood neutrophils to human C5a and ovine IL-8 was increased by dexamethasone treatment. Lymphocyte proliferation in the presence of phytohaemagglutinin, and serum concentrations of IgM, but not IgA or IgG1, were suppressed by dexamethasone treatment, whereas mitogen-induced production of interferon- (IFN-), neutrophil expression of CD18, neutrophil myeloperoxidase activity and natural killer (NK) cell activity were not influenced by dexamethasone treatment. The results indicate the potential for haematology and immune function assays to reflect elevated activity of the hypothalamic–pituitary–adrenocortical axis in cattle. Immunological parameters may thus provide a useful adjunct to cortisol and behavioural observations for assessing the impact of stress on the welfare of cattle.     

湘西黄牛发情周期与妊娠早期孕酮变化规律研究

采集湘西黄牛母牛的血液样品,通过酶联免疫吸附技术检测和比较其在发情周期和早期妊娠期的孕酮(P4)水平。结果表明,湘西黄牛的发情周期中,P4浓度变化非常明显,大致呈先上升再下降的趋势。发情前期、中期、后期和间情期P4浓度分别为8.85、0.72、1.40和9.13ng/mL,发情中期与后期P4浓度显著低于发情前期和间情期(P0.05);妊娠早期的母牛,从发情配种后,血液中P4浓度缓慢升高,其中妊娠后0~10d、11~20d、21~30d和31~36dP4浓度分别为3.36、8.91、12.69和16.12ng/mL,各阶段P4浓度差异显著(P0.05);发情后第21d、24d、27d和30d,妊娠母牛血液中的P4浓度显著高于未妊娠的母牛(P0.05)。试验表明,发情配种后20d,妊娠母牛与未妊娠母牛的血液中孕酮含量差异明显,可作为判断是否受孕的标记因子。     

一起肉牛球虫病的诊治

2020年5月,河南南阳某养殖场发生以血痢为主,常规治疗无效的情况。随即进行临床初步诊断并采集新鲜粪便样品进行实验室检测,结果显示为球虫感染引起的腹泻。经综合治疗,病情得到有效控制。     

重度联合免疫缺陷（SCID）小鼠排卵,胚胎发育能力及妊娠母体激素动态

为探讨先天性Ｔ－Ｂ淋巴细胞联合缺陷对生殖功能的影响,用正常ＢＡＬＢ／ｃ小鼠作对照,对重度联合免疫缺陷（ＳＣＩＤ）小鼠的排卵,胚胎（胎儿）发育能力及妊娠体外周血浆促黄体素（ＬＨ）和孕酮（Ｐ）水平的变化进行了研究。首先,观察了妊娠期、窝产仔数,发现ＳＣＩＤ小鼠大多在妊娠第２０天（检栓当天为第１天）凌晨分娩,平均窝产卫数为３．８６±１．６７）只,ＢＡＬＢ／Ｃ小鼠多在妊娠第２０天较晚或第２１天凌晨分娩,平     

妊娠相关糖蛋白(PAG)在奶牛早期妊娠诊断上的应用现状

妊娠相关糖蛋白(pregnancy associated glycoproteins,PAG)是反刍动物妊娠后外周血液出现的特异性蛋白,在妊娠过程中发挥着重要的作用。目前,在生产上通过检测PAG在血清中浓度能够进行奶牛的妊娠诊断。作者综述了PAG的发现、分离纯化及其在奶牛体内的代谢水平和近年奶牛早期妊娠诊断上的应用情况。     

黄牛实验性瘤胃切开术血液流变学主要指标变化规律研究

为了探讨黄牛瘤胃手术血液流变学主要指标的变化规律和指导术后治疗用药 ,对 1 0头健康成年黄牛瘤胃手术前后 2周的血液流变学 ,即全血比粘度 ( ηb) ,血浆比粘度 ( ηP)、红细胞压积 ( HCT)、全血还原比粘度 ( ηr)、血红蛋白含量 ( HB)、红细胞沉降速度 ( ESR)、红细胞聚集指数( AI)和纤维蛋白质含量 ( FG)等 8项指标进行了系统检测。结果表明 :1 0头黄牛在瘤胃手术后一周内其 ηb、ηP、ηr、ESR、HCT、AI和 FG值比术前极明显增高 ( P<0 .0 1或 P<0 .0 5 ) ,且 HB值也有明显升高 ( P<0 .0 5 )。黄牛因外科手术中紧张不安 ,机体的应激以及术中和术后血液的流失 ,可对血液流变性产生影响 ,此实验对外科手术前后的处理输液用药具有重要意义     

低剂量促性腺激素处理诱导黄牛一胎双犊的研究

本文研究了应用低剂量促性腺激素处理诱导黄牛一胎双犊。分析了影响成功率的因素。结果表明：采用PMSG与HCG、PMSG与PG及FSH与PG对母牛进行处理,其受胎率分别在80％～95％、84％～91．8％和85％～100%之间,与自然发情组的90％相比无显著差异;但在双犊率方面,自然情况下产双犊率仅为0．92％(0．85％～1．00％),而PMSG与HCG处理组的双犊率在11.3％(11．0％～11．8％),PMSG与PG处理组为13．0％(11．0％～15．8％),FSH与PG处理为19．6％(11．0％～27．0％),说明应用激素处理诱导双胎是有效的,而且不同处理方法之间的效果也不同。对应用FSH与PG处理组所产双犊的出生重、1月龄、3月龄、6月龄体重进行了测定,并与出生时间相近、饲养条件相同的自然单胎犊牛进行了比较。结果表明,双犊的平均出生重、1月龄体重、3月龄体重与单胎组差异显著,但6月龄体重差异不显著,加强双胎犊牛哺乳期饲养管理十分重要。     

miR-93对延边黄牛垂体细胞GH分泌的影响

为了分析血液外泌体miRNA对延边黄牛垂体细胞生长激素（GH）分泌的影响,试验选择在延边黄牛和韩延牛血液外泌体中存在显著差异表达的miR-93,分析其对延边黄牛垂体细胞GH分泌的影响机制。试验首先进行延边黄牛垂体细胞的原代培养,之后将miR-93的mimics（miR-93-mi组）、mimics对照品（NC对照组）、inhibitor（miR-93-in组）、inhibitor对照品（iNC组）转染给已建立的垂体原代细胞,48 h后收集细胞,提取总mRNA和总蛋白。试验利用targetscan和RNAhybrid分析软件对miR-93的靶基因进行预测,并利用双荧光素酶报告基因系统对miR-93的靶关系进行验证;利用实时荧光定量PCR和Western blotting技术分别检测靶基因mRNA转录和蛋白的表达情况,结果表明,miR-93靶向了生长激素释放激素受体（GHRHR）的3'UTR;与NC对照组比较,miR-93-mi组的延边黄牛垂体细胞中GH mRNA转录和蛋白表达均极显著低于NC对照组（P<0.01）;miR-93-mi组的GHRH mRNA转录和蛋白表达均极显著低于NC对照组（P<0.01）,而miR-93-in组的GHRHR蛋白表达显著高于iNC对照组（P<0.05）。说明miR-93可通过调节GHRHR的表达而调控延边黄牛垂体细胞GH的分泌,进而调控延边黄牛的生长发育。     

Hepatic steroid inactivating enzymes,hepatic portal blood flow and corpus luteum blood perfusion in cattle

Production from the corpus luteum (CL) and/or hepatic steroid inactivation impacts peripheral concentrations of P4, which can alter reproductive performance. Our primary objective was to examine hepatic steroid inactivating enzymes, portal blood flow, and luteal blood perfusion at 10 days post‐insemination in pregnant versus non‐pregnant beef and dairy cows. Twenty early lactation Holstein cows and 20 lactating commercial beef cows were utilized for this study. At day 10 post‐insemination, hepatic portal blood flow and CL blood perfusion were measured via Doppler ultrasonography. Liver biopsies were collected and frozen for later determination of cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A), uridine diphosphate‐glucuronosyltransferase (UGT) and aldo‐keto reductase 1C (AKR1C) activities. Pregnancy was determined at day 30 post‐insemination and treatment groups were retrospectively assigned as pregnant or non‐pregnant. Data were analyzed using the mixed procedure of SAS. Steroid metabolizing enzyme activity was not different (p > .10) between pregnant versus non‐pregnant beef or dairy cows. Hepatic portal blood flow tended (p < .10) to be increased in pregnant versus non‐pregnant dairy cows. Luteal blood perfusion was increased (p < .05) in pregnant versus non‐pregnant dairy cows. Pregnant dairy cows appear to have an increased rate of hepatic clearance of P4 in combination with increased synthesis from the CL. This could account for the lack of difference in peripheral P4 concentrations between pregnant and non‐pregnant dairy cows. This study highlights the relevance of further investigation into steroid secretion and inactivation and their impact on the maintenance of pregnancy in cattle.     

牛场的粪污无害化处理技术

近几年来,随着我国经济的快速发展,人民的生活水平得到了提高,对畜产品的需求量也逐渐增大,周至县的畜牧业得到了迅速发展。随之引发的畜禽粪污处理问题也日渐突出,做好畜禽粪污资源化利用,对于改善全县农村人居环境、畜牧业稳步发展、落实国家乡村振兴具有重要意义。     

牛产后败血症及脓毒血症防治

牛产后败血症以全身症状表现为主,体温高热稽留,死亡率较高;脓毒血症以组织器官化脓为主要特征表现。预防该病需做好母牛疾病防控及产后护理,科学助产;抗生素是治疗该病的最佳药物,治疗该病建议采用局部和全身相结合的方案进行用药,同时,为加速疾病康复还应配合保健用药。     

西门塔尔牛BVD预防和治疗试验

肉牛的呼吸道疾病(BVD)多因运输应激而引起的一种顽固性疾病,常因临床治疗效果不佳,饲养成本增加。为降低本病给牧场造成 损失,自2020 年03 月26 日起,针对华润集团开鲁隔离场 牧场购自伊胡塔交易市场的西门塔尔品种架子牛,使用德国勃林格公司育肥牛到场操作流程方案进行应激处理并跟踪各项数据,与单纯使用勃林格公司驱虫药害获灭做对比评估,通过药物成本、死淘情况、增重指标的对比来评估方案优劣及成本核算分析,结果显示：(1)同样品种的西门塔尔育肥牛,在采购进入育肥场前后,进行不同应激处理方案,相比较只做害获灭+FMD 疫苗处理的牛群,使用专克灵+害获灭+FMD 疫苗处理的牛群,平均每头牛的日增重差别可以达到0.3kg/d,根据目前市场行情条件下,育肥牛销售约32 元/kg 的价格,在入场30 日内,平均每头牛可以多获得239.6 元的更多增重育肥收入;(2)在入场后使用专克灵预防BRD,配合害获灭驱虫,相比较入场后只做驱虫处理,能获得更低的BRD 发病率(低28.7%),发病牛更短的治疗天数(少0.5 d),更佳的平均日增重(多300 g),能够带来更好的增重收益;(3)实验组与对照组差别为0.3kg即平均日增重差别300g 。该数据可以直观的说明,入场时,是否全群专克灵处理牛群,预防BRD,对于后续日增重的影响,差异极其明显。本试验为华润集团隔离场领导及牧场技术人员参考。     

兽医临床上常见黄牛异常发情的防治措施

随着农业机械化不断地推广,二牛抬杠式的原始农业耕作方式逐渐退出了农业生产。取而代之的农业机械化耕作,以前用来耕地的黄牛用途逐渐变成了产犊为主,农田里不见了黄牛耕作的身影,山坡不见了放牛人。取而代之的是舍饲圈养,肉牛以集约化育肥为主的养殖方式。通过对兽医临床遇到的病例统计发现,母牛的异常发情病例逐渐增多,高达30%~40%。作者根据实际兽医临床工作发现一个规律,一到冬季产犊季,母牛难产增多;母牛产犊后农户就会天天用玉米糊糊饲喂,瘤胃积食也会增多,冬季青贮饲草料价格高,资源匮乏,担心母牛产犊后掉膘,乳汁分泌不足,在这个过程中,很多母牛就会出现虚胖,犊牛腹泻,母牛伤食泻瘤胃酸中毒,最主要的是产犊后的母牛长期大量精料饲喂导致母牛体质偏胖,在中兽医诊断上就属于一种寒湿瘀滞的体质,卵泡不发育或者是发育不良。再加上畜主长期不正确的使用各种兽药,造成滥用药,致使动物机体损伤养殖业是一个需要倾注大量心血的行业,天道酬勤,养殖场户的辛勤付出才能换来牛羊的牧草丰富,茁壮生长,动物防疫工作者的辛勤付出才能换来动物群体的健康稳定,畜牧兽医工作者与农户一起服务于动物从配种到出栏。     

黄牛吸入性异物肺炎的诊治

黄牛吸入性异物肺炎,是因吸入尘埃、饲草和刺激性气体或灌药误入气管所致的以剧烈咳嗽为特征的肺部疾病。论文通过对一起群发本病的重危病例临床诊治,认为抓住最佳治疗时机与实施合理的治疗方案,对于避免急性死亡、控制病情恶化和实现康复颇有意义。     

The Effect of Energy Balance on Ovarian Activity in a Herd of Norwegian Cattle

The study involved 34 primiparous cows fed ad libitum grass silage and fixed amounts of concentrate per cow and stage of lactation. It revealed that number of days from calving to maximum progesterone concentration in first luteal phase was negatively related to (p<0.05) energy balance summarized over weeks 3-12 post-partum. One standard deviation improvement of the summarized energy balance relative to the mean reduced the length of the anovulatory period by 12 days. Similarly, an improved energy balance enhanced progesterone secretion during the oestrus cycle and early pregnancy, as measured by 3 variables; 1) maximum progesterone concentration in first luteal phase, 2) cumulative progesterone secretion bounded by the maximum concentrations in first and in third luteal phase and 3) cumulative progesterone secretion in the first month of pregnancy. All results were supported by the estimated regression coefficients of the 4 ovarian activity variables on summarized non-estrified fatty acids and ac-etoacetate variables.     

规模化奶牛场粪便的无害化处理措施

随着养牛业规模化、集中化发展,牛粪资源化利用日益凸显。从奶牛养殖污染防治角度出发,阐述规模化牛场粪便污染现状,介绍了堆肥技术、发酵技术、沼气生态模式在牛场粪便污染处理中的应用,旨在为提高牛场粪便处理效率,为促进奶牛养殖业的健康、快速发展提供参考。     

肉牛子宫脱出产科病的综合治疗

为了对肉牛子宫脱出产科病进行综合治疗,提高治疗的效果。本文分析了引起肉牛子宫脱出的因素、发病的临床症状。针对临床症状进行了手术治疗、西药治疗、中药辅助治疗以及加强饲养管理,治愈效果明显提高。采用手术法、中西结合综合治疗肉牛子宫脱出。     

肉牛食用桃树叶中毒的诊治体会

桃树是我国广泛分布的树种,当牛在放牧或圈养时食用了较多的桃树枝叶,可引起中毒,以春季新鲜牧草缺乏时发病较多,且不分品种和年龄均可发病,多于采食后数小时至数天内发病。笔者从医几年来,偶遇两例牛误食桃树枝叶中毒病例,现将诊治体会分享如下。     

牛羊养殖中细菌性疾病防治

牛羊养殖技术不断增强,养殖中加强对于各类疾病的处理预防和控制也至关重要,需要不断完善相关管理措施,提升各系统类型疾病的预防效果,提升牛羊养殖业的整体收益,细菌性疾病是牛羊养殖中较为常见的一种病症类型,在实际养殖中需要明确了解细菌性传染病的发病原因,且在实际牛羊养殖中,需要通过对牛羊的生理表现及临床症状的关注,了解其病变情况,分析其是否存在细菌感染情况及时开展相应的控制措施。