山羊子宫感染大肠杆菌后TLR4、β防御素2和细胞因子mRNA表达变化

12只产后25 d健康奶山羊随机分为2组,即试验组和对照组.试验组将大肠杆菌O46经子宫角插管注入山羊子宫腔内制作山羊子宫内膜炎病例模型,对照组向子宫腔内注入等量的生理盐水.分别于注菌前(0 h),注菌后3,6,12,24,72,120,168 h进行临床检查、细胞学检查和子宫内膜活检采样.子宫内膜组织分为2份,一份用于制作组织学切片,另一份用于提取RNA,用荧光定量PCR的方法检测TLR4、细胞因子和β-defensin 2 mRNA表达的变化.结果显示,试验组山羊在注菌后呈明显的炎症反应,体温升高,呼吸急促,白细胞增多,阴道流出脓性分泌物;％PMN极显著升高(P＜0.001);组织学显示大量的炎性细胞浸润于子宫内膜组织;TLR4、细胞因子和β-defensin 2 mRNA表达显著升高.对照组山羊未有明显的炎症反应症状.     

奶牛子宫内压描记试验及胎衣不下与产后子宫活动性关系的初探

本实验在国内首次建立了描记奶牛子宫内压的体内微型压力传感器法,为对子宫进行生理、病理及药理学研究提供了一个实用手段。 本实验利用压力传感器法描记了16头母牛产后4小时和24小时的子宫内压并同时测定了血浆17β-雌二醇和孕酮的水平,其中胎衣正常排出7头(NRFM),胎衣不下9头(RFM)。结果如下:产后4小时NRFM和RFM牛子宫活动单位(平均收缩压×10分钟收缩次数)分别为183.19±19.15和37.12±16.79(P<0.01);产后24小时子宫活动单位NRFM牛为32.75±4.5,RFM牛为31.65±6.33(P>0.05),此时静注30单位催产素后子宫活动单位分别增加17.4和5.5倍(P<0.01)。NRFM牛产后4和24小时血浆17β-雌二醇水平为99.96±42.69和27.16±10.92pg/ml,RFM牛为188.06±63.85和106.93±72.28pg/ml(P<0.01);产后4和24小时血浆孕酮水平NRFM牛为2.0802±0.4072和1.9815±0.4312ng/ml,RFM牛分别为1.9635±0.6208和1.8734±0.6017ng/ml(P>0.05)。     

产后奶牛子宫内膜的扫描电镜观察

应用扫描电镜观察了 5头奶牛产后不同时期子宫内膜的变化。结果发现 ,分娩后早期 ,奶牛子宫内膜部分破损 ,与破损部位相邻的细胞在产后 1周内相继脱落 ;未破损内膜上皮细胞表面的纤毛和微绒毛形状不整、数量减少。产后2周 ,基底细胞开始生长 ,至产后 4 5 d时生长完成 ;产后 4周 ,内膜破损区域缩小 ,上皮细胞表面纤毛和微绒毛形状规则、数量增加 ;产后 4 5 d,偶见上皮细胞缺失 ;至产后 6 0 d,子宫内膜上皮细胞完整、排列有序、被覆纤毛和微绒毛。上述结果表明 ,奶牛子宫内膜在分娩后 6 0 d内完成修复。     

奶牛产后胎衣不下的诊治

奶牛胎衣不下是奶牛重要的产科疾病之一,是奶牛的一种常见疾病,影响奶牛的正常受孕和产奶,也可以导致其他疾病,例如病牛容易继发子宫内膜炎和导致不孕症,使奶牛繁殖能力降低。牛分娩后胎衣排出的正常时间为3～8小时。一旦超过12小时以上胎衣仍不能完全排出,即为病理现象,称作胎衣不下或胎衣停滞。该病以年老而高产牛多发,一般第3胎次以上奶牛较容易发生,一般发病率为3％～12％,有的高达30％～50％。     

雌激素对产后奶牛免疫功能,子宫感染的影响研究

将３２头产后妈牛随枘发成对照组（ｎ＝１２）和用药组（ｎ＝２０）,用药组奶牛产后第９,１０天肌注２０ｍｇ雌激素。在两组奶牛产后３,５,７,９,１１,１３,１５天采集子宫分泌物,涂片,染色,镜检。结果发现用药后子宫粘液涂片中嗜中性白细胞、淋巴细胞及白细胞总数比同时期对照组显著增加（Ｐ〈０．０１）,比用药前组内的各时期显著增加（Ｐ〈０．０１）,并且用药组产后２１天子宫炎发生率为１０％,而对照组为３３％,     

奶牛产后胎衣不下的诊治

在本地区散养户饲养的奶牛,几十年来多数处于圈舍饲养管理,产后胎衣不下的母牛很常见。经多年来的治疗、实践证明,不及时治疗和剥离,或者治疗方法不恰当,胎衣长时间滞留难脱落的。产后第2~3个发情周期,虽然有发情表现,直肠深部触诊常伴有慢性子宫内膜炎(内膜肥厚),或者卵巢疾患,造成多个情期乃至1年授配难孕(屡配不孕)。泌乳量大量减少,直至淘汰出售。给农户造成一定的经济损     

预防奶牛产后子宫感染的研究

本研究选择临床上较为常用的律胎素（氨基丁三醇前列腺素F2α）、中药（黄芩苷、硫酸小檗碱、天花粉）、聚维酮碘、得米先等药物,应用于子宫,预防奶牛产后感染,并通过B超监测产后各组牛的子宫颈、孕角、空角变化。结果表明,律胎素联合应用中药、聚维酮碘或得米先对预防奶牛产后子宫感染、促进子宫恢复均具有较好的效果。     

蒙古马不同组织器官TLR1、TLR2、TLR4和TLR6 mRNA转录水平研究

根据GenBank中马Toll样受体基因序列设计特异性引物,建立检测马Toll样受体（TLRs）mRNA转录水平的SYBR GreenⅠ实时荧光定量PCR方法,检测TLR4、TLR2、TLR1和TLR6在蒙古马不同组织器官中的转录水平。4种TLRs在心脏、肝脏、脾脏、肺脏、肾脏、胃、十二指肠、空肠、盲肠和骨髓中均有转录。其中,TLR4mRNA除在空肠和肝脏外,在其他组织器官中的表达水平均高于TLR2、TLR1、TLR6。免疫器官中,TLR4、TLR1mRNA在骨髓中表达量高于脾脏,而TLR2、TLR6mRNA在脾脏中表达量高于骨髓。各肠段,TLR4、TLR2、TLR1、TLR6mRNA表达水平之间在空肠的差异不是很大,而在十二指肠和盲肠中差异很大。结果表明,TLRs mRNA在马各组织器官转录水平差异较大,可能与其对病原体的识别和抵抗能力有关。     

雏鸡不同组织TLR1、TLR2、TLR4、TLR5和TLR15 mRNA转录水平相对定量研究

参考GenBank登录的ChTLRs基因序列设计实时定量PCR特异性引物,建立检测鸡Toll样受体(ChTLR)mRNA相对转录水平的实时定量PCR方法,分析ChTLR1、ChTLR2、ChTLR4、ChTLR5和ChTLR15在雏鸡不同器官组织中的转录水平。结果显示5种ChTLRs在脾脏、法氏囊、胸腺和各段肠道组织中均有转录。其中,ChTLR1 mRNA在法氏囊、肾脏和盲肠组织中转录水平较高;ChTLR2 mRNA在脾脏、法氏囊和肝脏等组织中转录水平较高,在肾脏、肺脏和皮肤未检测到转录;ChTLR4 mRNA在所检测组织中转录水平差异较小,在脾脏、十二指肠和胸腺转录水平较高;ChTLR5 mRNA在肾脏、脾脏和空肠中的转录水平较高;ChTLR15 mRNA在法氏囊中转录水平最高,其次为脾脏和盲肠。本研究建立了检测ChTLRs mRNA在不同器官组织中表达水平的实时定量PCR方法,ChTLRs mRNA在雏鸡各器官组织中转录水平差异较大,可能与雏鸡各器官组织对病原的识别和抵抗能力有关。     

金定鸭不同组织和血液中TLR1、TLR2、TLR4、TLR5的表达差异分析

试验旨在研究不同Toll样受体（Toll-like receptor,TLR）在鸭不同组织中的表达情况,选取300日龄雄性金定鸭10只,解剖后采集其血液及脾脏、肝脏、睾丸、肺脏、下丘脑、垂体、皮肤、腿肌、心脏、肾脏、胸肌、盲肠、小肠、胸腺,采用Primer Premier 5.0软件设计特异性引物,并用实时荧光定量PCR法检测TLR1、TLR2、TLR4、TLR5在不同组织中的相对表达情况。结果显示,各基因扩增产物的熔解曲线均有一特异性的单峰,无其他杂峰,说明引物的特异性较强,可以准确定量。4种目的基因与内参基因的扩增效率在101.4%~105.0%之间,均接近100%,相关系数（R²）为0.98~1.000。TLR1、TLR2、TLR4、TLR5 4种TLRs在金定鸭不同组织和血液中均有表达,但每种TLR受体在各组织中表达水平略有差异,其中TLR1在下丘脑中表达量最低,在胸肌中最高;TLR2在小肠中的表达量最低,在肺脏中最高;TLR4、TLR5在睾丸中的表达量最低,在皮肤中最高。以上结果说明,鸭TLRs在多种组织中能够广泛表达,本试验结果可为TLRs在鸭源感染过程中的作用机理研究提供科学依据。     

A hospital-based study of the relationship between retained placenta and mastitis in dairy cows

We investigated the relation between retained placenta and mastitis in Holstein dairy cows admitted to the New York State College of Veterinary Medicine. Cows with retained placenta were three times more likely to develop mastitis during hospitalization than animals without retained placenta. Since the hospital population was not representative of the general population, the possibility of a bias existed; a large bias was not likely because most distorting variables occurred equally in animals both with and without retained placenta. The literature suggests that the relationship between retained placenta and mastitis may be mediated through activity of the peripheral leukocytes. Further research is necessary to test this hypothesis.     

Short-term changes in serum luteinizing hormone, ovarian response and reproductive performance following gonadotrophin releasing hormone treatment in postpartum dairy cows with retained placenta.

Thirty-six postpartum Holstein cows consisting of eighteen cows that shed the placenta soon after calving (NRP) and eighteen cows that retained placenta greater than 24 h (RP) were used. There were four treatment groups. Group I consisted of 9 NRP cows which received intramuscular injection of sterile saline on day 15 postpartum. The second group consisted of 9 NRPN cows which received 100 micrograms of gonadotrophin releasing hormone on day 15 postpartum (NRPT). The third group consisted of 9 RP cows which received saline on day 15 postpartum (RPN) and the fourth group consisted of 9 RP cows which received 100 micrograms of gonadotrophin releasing hormone on day 15 postpartum (RPT). Blood samples were collected once daily during the first month and once every other day during the second month postpartum. In addition fourteen cows (RPT, n = 7; NRPT, n = 7), were used to study short-term changes in serum luteinizing hormone concentrations following gonadotrophin releasing hormone treatment on day 15 postpartum. Blood samples were obtained from these cows every 15 min during 1 h before and 6 h after gonadotrophin releasing hormone administration. Sera from all samples were assayed for progesterone and luteinizing hormone concentrations. Starting from four days after calving rectal palpations and ultrasound examinations of the ovaries were carried out once every four days until day 28 postpartum in order to monitor ovarian changes. All cows were inseminated on the first estrus after day 60 postpartum and examined for pregnancy between 35 and 42 days after insemination.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of gonadotrophin releasing hormone on reproductive performance of dairy cows with retained placenta.

The effects of gonadotrophin releasing hormone (GnRH) on the reproductive performance of dairy cows with retained placenta were studied. Three hundred and seventy-eight cows diagnosed as having retained placenta received intramuscular injections of either 2 mL sterile water or 200 micrograms of GnRH in 2 mL sterile water between day 8 and day 14 postpartum. Rectal palpation was performed at the time of treatment and ten to 20 days after treatment in order to determine the rate of uterine involution. Thereafter, monthly rectal examinations were carried out until insemination. Pregnancy diagnosis was made by rectal palpation at 40 days or more after breeding. Using the entire experimental population, there were no significant differences between GnRH-treated and control cows for the rate of uterine involution, the occurrence of reproductive problems, the interval from parturition to first observed estrus, the interval from parturition to first insemination, the interval from parturition to conception, the number of services per conception, the total number of services per cow regardless of conception and the incidence of culling for infertility. When the data for herds in which breeding began earlier in the postpartum period (herds having a mean less than or equal to 80 days from parturition to first service for retained placenta cows) were considered, the GnRH treatment resulted in a significantly shorter (p less than or equal to 0.01) calving to conception interval as compared to control cows. Also, there was a significant reduction (p less than or equal to 0.05) in the total number of services per cow regardless of conception and a significant reduction in the interval from parturition to first service.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immune responses during the peripartum period in dairy cows with postpartum endometritis

Determining the immune responses to the development of endometritis during the peripartum period may assist in the development of more efficient reproductive management regimens for dairy herds. In this study, we compared the peripartum immune responses of dairy cows that develop endometritis by 4 weeks postpartum (n = 11) to cows that did not develop this disease (n = 19). Blood samples were collected 1 week before calving, just after or during calving, and then at weeks 1, 2, 3, and 4 postpartum. Cows that developed endometriris had significantly higher total leukocyte, neutrophil, lymphocyte, and monocyte counts than the control cows (P < 0.05) at all time points. The leukocytes from cows that developed endometritis were significantly less phagocytic than those from control cows at all sampling time points (P < 0.01). The serum TNFalpha concentrations of the control cows decreased linearly from the prepartum time point (P = 0.0029), but the endometritis cows showed a different profile (P > 0.05). As a result, the serum TNFalpha concentrations were greater in the endometritis group (P < 0.01) than in the control group during the third and fourth weeks postpartum. The greater total leukocyte numbers and neutrophil, lymphocyte and monocyte counts, and the maintenance of elevated serum TNFalpha levels in the cows with endometritis may be due to infection in the postpartum period. Furthermore, the decreased phagocytic capacity of leukocytes during the peripartum period, including at the prepartum time point, makes cows more susceptible to postpartum endometritis.     

The relationship between mastitis and retained placenta in a commercial population of holstein dairy cows

The relationship between retained placenta and mastitis was studied in a population of dairy cows on commercial farms. Only mastitis cases which occurred shortly after calving were studied. The cows with retained placenta were at a higher risk of developing non-severe mastitis (relative risk = 1.5) and at a much higher risk of developing severe mastitis (relative risk = 5.4). There was a differential effect of long-term (> 6 days) versus short-term (< 5 days) retained placenta.It is suggested that the relationship between retained placenta and mastitis is moderated by the prepartum peripheral leukocyte activity.     

Economic and reproductive consequences of retained placenta in dairy cattle

The financial losses due to retained placenta in Dutch dairy cattle were estimated by using two different methods of calculation. A data-set containing the birth records of 160,188 Meuse-Rhine-Yssel cows provided data on the reproductive performance of cows with and without retained placenta. The fertility of cows after retention of the placenta appeared to be affected. An economic calculation made by adding the losses due to increased calving interval, increased culling rate, loss of milk production and the costs of veterinary treatment and drugs revealed that the total loss due to retained placenta was 471 pounds per year for a 100-cow farm with an average incidence of the condition (6.6 per cent). For a 'problem' farm with a 30 per cent rate, the loss was 2139 pounds per year. A computer farm simulation model, based on a stochastic determination of events, was used to make calculations for circumstances closely resembling those on farms. A 6.6 per cent rate of retained placenta caused a small but significant decrease in net return on labour and management; however, a 30 per cent rate caused highly significant changes. The economic effects of retained placenta were similar in magnitude in herds of high or low productivity and high or low fertility. Sensitivity analysis showed that the greatest financial losses were caused by loss of milk production, followed by the number of animals suffering from complications. The financial losses in herds with an average rate of retained placenta were thus of limited economic importance and therapeutic measures alone should be adequate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rationale for treatment of retained placenta in cows with neomycin and metronidazole.

A combination of neomycin and metronidazole was compared with oxytetracycline for its activity against the intrauterine flora of 10 cows with retained placenta. In vitro the metronidazole/neomycin combination reduced the numbers of aerobic and obligately anaerobic bacteria much more effectively than did oxytetracycline.     

Occurrence of retained placenta is preceded by an inflammatory state and alterations of energy metabolism in transition dairy cows

Background: Failure to expel fetal membranes within 24 h of calving is a pathological condition defined as retained placenta(RP). The objective of this investigation was to evaluate whether there are alterations in several selected serum variables related to innate immunity and carbohydrate and lipid metabolism that precede occurrence of RP in transition Holstein dairy cows.Methods: One hundred multiparous Holstein dairy cows were involved in the study. Blood samples were collected from the coccygeal vein during the-8 to +4 wks around parturition, once per week before the morning feeding.Six healthy control cows(CON) and 6 cows with RP were selected and serum samples at-8,-4, time of diagnosis of disease, and +4 wks relative to parturition were used for analyses. All samples were analyzed for lactate, nonesterified fatty acids(NEFA), β-hydroxybutyrate(BHBA), interleukin-1(IL-1), interleukin-6(IL-6), tumor necrosis factor(TNF), haptoglobin(Hp), and serum amyloid A(SAA).Results: Cows with RP had greater concentrations of serum lactate, IL-1, IL-6, TNF, and SAA in comparison with CON cows. Intriguingly, elevated concentrations of all five variables were observed at-8 and-4 wks before the occurrence of RP compared to healthy cows. Cows with RP also had lower DMI and milk production vs CON animals; however milk composition was not affected by RP.Conclusions: Cows with RP showed an activated innate immunity 8 wks prior to diagnosis of disease. Overall results suggest that serum IL-1, IL- 6, and TNF, and lactate can be used as screening biomarkers to indicate cows that might have health issues during the transition period.