超声多普勒检测仪对奶牛早期怀孕诊断试验

应用ＳＣＤⅡ型兽用超声多普勒检测仪对５１ 头受配乳牛进行了早期怀孕诊断，并与直肠检查结果进行验证。结果：２０ ～３０ｄ 、３１ ～６１ｄ 、６１ ～７５ｄ 的符合率分别达８６７ ％ 、１００ ％ 、１００ ％ 。对１２ 头未孕牛检测的符合率为１００ ％ 。试验结果证明，应用超声多普勒仪检测宫血音进行奶牛早期妊娠诊断效果良好。     

诱导妊娠母猪白天分娩及其机理的研究

用氯前列烯醇对妊娠后期母猪作一次性肌注，从注射前至分娩开始，以１２小时为间隔采血，然后用放射免疫法分析血样，发现注射前血浆孕酮含量较高（１５．９５ｎｇ／ｍｌ），以后逐渐显著下降，分娩时降低到最低（５．３９ｎｇ／ｍｌ）。这说明外源性氯前列烯醇对母猪分娩前妊娠黄体有溶解作用，可导致母猪分娩提前发动。实验发现，在妊娠期１１０天、１１１天和１１２天处理母猪的白天分娩率分３１１为９０％（１８／２０）、８８．２４％（１５／１７）和７５％（１２／１６）；不同处理剂量（０．０５ｍｇ。０．１ｍｇ、０．２ｍｇ）的白天分娩率分别为８６．９６％（２０／２３）、８７．５％（１４／１６）和７８．５７％（１１／１４）；实验组的平均白天分娩率（８４．９１％，４５／５３）显著高于对照组（４５．６５％，２１／４６）；处理至分娩间隔时间平均为２４小时２４分钟。     

大足黑山羊妊娠不同阶段胎盘组织线粒体酶活性和超微结构变化

山羊的胎盘属于子叶型胎盘,胎盘子叶性状和结构与山羊繁殖性能具有较强的相关性。胎盘子叶组织线粒体发挥正常功能是保证胎儿生长发育,进而维持正常妊娠的关键。本试验采用大足黑山羊妊娠60,90,120d的胎盘和胎儿组织为研究对象,检测胎盘子叶及胎儿心、肝、脾、肺、肾组织的线粒体细胞色素C氧化酶(CCO)、琥珀酸脱氢酶(SDH)、Ca++-Mg++-ATP酶和Na+-K+-ATP酶的活性变化,并通过透射电镜技术观测胎盘子叶组织线粒体的形态结构。结果发现,胎盘子叶及胎儿心、肝、脾、肺、肾的线粒体CCO、SDH及ATP酶的活性都有随着妊娠时间的增加而显著提高的趋势,且在妊娠90~120d的上升趋势高于妊娠60~90d,表明妊娠中后期的胎儿生长发育所需要的能量较多;在同一妊娠阶段,胎盘子叶线粒体酶活性均高于胎儿各组织,且差异显著(P<0.05),说明胎盘子叶是妊娠过程中的重要部位,胎儿组织器官在发育过程中存在先后顺序,并且与该器官的功能作用有关;透射电镜观察发现,随着妊娠时间的增加胎盘线粒体数量增多,密度增大且主要聚集在子叶绒毛附近,这体现了胎盘子叶的营养交换作用。     

牛体外受精技术研究

卵巢卵母细胞培养于Ａ、Ｂ、Ｃ三种成熟液内的体外成熟率分别为９４．６１％、８９．４７％和７０．４３％，体外受精率分别为７１．８６％、７８．９５％和４０．８７％。受精卵培养于颗粒细胞单层、输卵管上皮细胞单层和中间受体的２￣４细胞发育率分别为４７．３１％、５４．９２％和６２．８１％，其桑椹胚发育率分别为１０．７５％、１２．３０％和１８．５９％。移植受体１１头，妊娠３头，移植妊娠率为２７．２７％，其中１头     

血小板计数法在奶牛超早期妊娠诊断上的应用

对２０头未孕母牛血小板正常值的测定结果为４９６．５×１０９／Ｌ±６６．５×１０９／Ｌ；对３０头受配母牛进行血小板值变化和最佳血检时间的试验，结果表明，２２头妊娠母牛于配种第７天血小板值明显减少（Ｐ＜０．０１）；而８头未妊娠母牛则无明显变化（Ｐ＞０．０５）。根据妊娠母牛配种前后血小板值差＞１９２．３×１０９／Ｌ为妊娠标准，对３０头受配母牛进行了超早期妊娠诊断试验，经直检妊娠母牛符合率为８６．３６％，空怀母牛符合率为８７．５％，总符合率为８６．６６％（Ｐ＞０．０５）。     

超声断层扫描观察苏北犬胚胎和胎儿发育

用5MHz线阵探头对14只母犬从配种后18d开始，每2d用B超探查1次；配种后36～48d，每3d探查1次；48d以后，于52、57d各探查1次。结果表明，于配种后18～22d确诊7只犬妊娠，7只空怀。有3只犬分剐在配种后24、36、39d发生流产。观察胎囊、胎儿、胎心、胎动、胎儿脏器、胎儿骨骼出现时间和测量胎囊大小、冠臀长、胎儿身长、头长、双顶径、胸深和心区大小，证明胎囊大小、胎儿冠臀长、身长、头长、双顶径、胸深与胎龄呈显著正相关。在配种后18～30d，观察子宫暗区大小可预测胎龄。在配种32d以后，观测胸深、双顶径或头长。可精确预测胎龄。     

牛用生长激素对绵羊母体胎儿等的影响

牛用生长激素对绵羊母体胎儿等的影响牛用生长激素（ＢＳＴ）经美国食品药物管理局（ＦＤＡ）批准，在奶牛中得到广泛的应用。本文探讨ＢＳＴ对绵羊母体、胎儿发育等的影响。试验选用平均日龄２９７ｄ、体重５９ｋｇ初妊娠绵羊１０头，分成对照和试验两个组，每组５头。试...     

应用PMSG,PMSG＋HCG和氯前列烯醇提高母猪繁殖试验

应用ＰＭＳＧ、ＰＭＳＧ＋ＨＣＧ和氯前列烯醇处理临床上健康的繁殖适龄“长Ｘ大”杂种母猪９６头，１０ｄ内同期发情率分别为９８．１５％、９９．３３％和９０．２３％，均与对照组的４６．７０％间有极显著差异（Ｐ〈０．０５）；情期受胎率分虽为９８．０５％、１００％和１００％、与对照组间无显著差异（Ｐ〉０．０５）；胎平均产仔数分别为１３．１头、１５．３头和１５．８头，均与对照组间差异不显著，但试验组胎平均产仔数     

兽用B超在克隆猪研究中妊娠诊断的应用

本研究利用B超诊断仪对3头克隆胚代孕母猪进行了早期妊娠诊断，有2头受体母猪妊娠, 检测到3个胎儿。对妊娠代孕母猪进行了连续的跟踪B超观察，发现1~2个克隆猪胎儿发育异常。产仔结果表明早期妊娠检测确诊阳性准确率100％，2个胎儿发育畸形而死亡，与观察结果一致。     

应用“猪妊娠诊断试剂”早期妊娠诊断

用“猪妊娠诊断试剂”对配种后１８天的１８５头母猪进行早期妊娠诊断试验，以产仔做为判断妊娠的依据，检出妊娠和空怀的准确率分别为９６．７％和１００％，任选其中５６头另用超声波诊断法进行早期妊娠诊断，检出妊娠和空怀的准确率分别为１００％和１８．２％，说明激素法诊断空怀的准确性优于超声波法。上外，激素法未引起母猪流产，并能诱导发情，而且操作简便，因此具有推广应用前景。     

Transabdominal and transrectal ultrasonography of fetuses in Württemberg ewes: Correlation with gestational age

It is useful to determine the gestational age in sheep to provide essential information for effective flock management practices. The aims of this study were to evaluate the efficacy and practical aspects for using two ultrasound techniques, transabdominal and transrectal, in determining the gestational age in Württemberg ewes. Monitoring of embryo and fetus developmental stages during the ewes’ gestation was carried out with real time ultrasound using a transabdominal convex probe, frequency 3.5 MHz, and a transrectal linear probe, frequency 7.5 MHz. The size of the embryonic vesicle during the period from the 23rd to the 38th day of gestation can be used as a confirmational indicator of gestational age when the transrectal probe is used. The occipital nasal diameter correlated with the gestational age with both transabdominal (P < 0.05) and transrectal probes (P < 0.01) from the 46th to the 63rd day of gestation. The biparietal diameter of the fetal head measured by transabdominal probe during the period from the 46th to the 63rd day of gestation correlates with gestation age (P < 0.05). The diameter of the fetal eye orbit monitored by transrectal probe from the 46th to the 63rd day of gestation also correlated well with gestational age (P < 0.05).     

Establishment of the prediction table of parturition day with ultrasonography in small pet dogs

To establish a prediction table of parturition day the real-time B-mode ultrasonographic examinations were performed in the 8 pregnant Malteses and 10 Yorkshire terriers (total pups, 25 and 38 pups, respectively) from 18 days of gestation until the parturition. Ovulation was designated the first day of gestation (day 0). Extra fetal and fetal structures were measured from all conceptues. The parameters that exhibited the best correlation to parturition were used to compile a prediction table of parturition day. To testify the precision of the prediction table of parturition day, the 15 pregnant Malteses (48 pups) and 13 pregnant Yorkshire terriers (42 pups) with unknown mating time were examined using ultrasonography. Inner chorionic cavity diameter on days 18 to 37 and fetal head diameter on day 38 to parturition that showed the best correlation to gestational age were the most pertinent to the estimation of gestational age and the prediction of parturition day. The two parameters were used to compile a prediction table of parturition with averaged regression equations. In verificational examinations, with the exception of I Yorkshire terrier (3.6%) having 1 fetus, 18 of 28 bitches (64.3%) delivered exactly on the date predicted and 9 of 28 bitches (32.1%) delivered within I day of the date predicted. Therefore, the prediction table of parturition day seems to be a useful tool of the prediction of parturition day in practice.     

Association between gestational age and bovine fetal characteristics measured by transcutaneous ultrasound over the right flank of the dairy cow

Objective   To determine bovine fetal characteristics significantly associated with increasing gestational age as measured via transcutaneous ultrasonography over the right flank.
Methods   The length of gestation at date of pregnancy diagnosis via transcutaneous and transrectal ultrasonography was determined for 224 dairy cattle by estimation from subsequent calving dates. A separate dataset was created for each measurable fetal characteristic (i.e. thoracic diameter, abdominal diameter, umbilical diameter, placentome length and placentome height) and risk factors significantly associated with gestational age at pregnancy diagnosis within each dataset, including the fetal characteristic, were identified.
Results   Abdominal diameter was the most frequently observed fetal characteristic and thoracic diameter was the least. Gestational age at pregnancy diagnosis (d) was significantly associated with fetal thoracic diameter (P < 0.01), abdominal diameter (P < 0.01) and umbilical diameter (P = 0.02) when measured via transcutaneous ultrasound. Within each model, sire breed, dam breed, dam age and/or calf sex were also significantly associated with gestational age. Gestational age at pregnancy diagnosis was not significantly associated with either placentome height or length (P > 0.05).
Conclusion   Fetal thoracic diameter, abdominal diameter and umbilical diameter were found to be significantly associated with gestational age between approximate days 73 to 190 of gestation. Transcutaneous ultrasonography may prove a useful method of estimating gestational age in the absence of accurate breeding records.     

Diagnosis of pregnancy and prediction of fetal age in red deer by real-time ultrasonic scanning

Sixteen pregnant red deer hinds were scanned using real-time ultra sound at regular intervals during the first 150 days of pregnancy. In the early stages of pregnancy, an intra-rectal linear array transducer was used but later in pregnancy the hinds were scanned externally with a sector scanner. Pregnancy was determined from 30 days of gestation by intra-rectal scanning, and from 50 days by external scanning. With advancing age the size of the fetus increased, and linear regressions of size on age gave residual standard deviations of 0.508 days for head diameter and 0.506 days for trunk diameter. It is concluded that this technique can be used to determine pregnancy with a high degree of accuracy from 30 days of gestation and to predict calving date from fetal measurements within the range 1.5 cm to 7 cm for head diameter or 0.5 cm to 8 cm for trunk diameter, corresponding to a fetal age range of 35 to 150 days.     

Altered muscle development and expression of the insulin-like growth factor system in growth retarded fetal pigs

We have used a porcine model of spontaneous differential fetal growth to investigate the effects of fetal size on muscle development. We hypothesized that altered muscle development may occur in small fetuses as a consequence of modified expression of selected genes of the insulin-like growth factor system. We examined the development of the Longissimus muscle (m. Longissimus) in small fetuses and their average sized littermates. We collected small for gestational age fetuses and their average sized sibling on days 45, 65 and 100 of gestation (term is 113-116 days). Small fetuses had significantly lower body weight at all three stages of gestation (p<0.05) and significantly reduced secondary to primary muscle fibre ratio in m. Longissimus on day 100 (p<0.05) compared to their littermates. On day 65, the expression of insulin-like growth factor receptor 1 and insulin-like growth factor binding protein 3 were significantly higher (p<0.05) in m. Longissimus of the small fetuses compared with their average sized littermates. On day 100, the expression of insulin-like growth factor receptor 1 remained significantly higher (p=0.001), in addition to significantly higher levels of insulin-like growth factor receptor 2 and insulin-like growth factor binding protein 5 in the small fetuses (p<0.05). No difference in levels of myogenin was observed between the small and average sized littermates. In conclusion, we demonstrate that reduced fetal muscle development is associated with an increased expression of several genes of the insulin-like growth factor system in small fetuses in mid to late gestation.     

Occurrence of Blood Cells and Serum Proteins in Bovine Fetuses and Calves

Hematological values of peripheral blood were determined for bovine fetuses and calves of various ages. Erythrocyte values increased through gestation. Fetuses 100 days or older had total values within the ranges of those reported for normal adult cattle. Mature erythrocytes were not observed in embryos and only a few were observed in fetuses 40 days of age. Fetuses 250 days or older had only a few rubricytes (<10/100 WBC). Leukocytes were first identified in the peripheral blood of a 45-day old fetus. Absolute leukocyte values increased through gestation and reached maximum values shortly before parturition. Granulocytes were first observed at 130 days of gestation and reached maximum values near parturition.

Total serum protein and gamma-globulin concentrations of colostrum-deprived calves were similar to serum protein and gammaglobulin concentrations of fetuses older than 265 days and were lower than values for the colostrum-fed calves. The immunoelectrophoretic pattern of 59-day old fetuses, the earliest age at which serum samples were obtained, demonstrated albumin, an α1 globulin and a β globulin, possibly transferrin. Additional α and β globulins appeared in the older fetuses and by 175 days of gestation serum electophoretic patterns of the fetuses were similar to patterns normally found with adult bovine serum except for the absence of the gammaglobulins in fetal serum. Immunoglobulin M was detected in 39 of 95 fetal serum samples by radial diffusion and in 13 of 95 samples by immunoelectrophoresis. Immunoglobulin G was detected in ten of 95 fetal serum samples by radial diffusion and in six of 95 samples by immunoelectrophoresis.

     

Determination of gestational age in medium and small size bitches using ultrasonographic fetal measurements

A study was undertaken to estimate gestational age, in terms of days from parturition, in medium and small size dogs by ultrasonographic examination. Serial ultrasonographic examinations were performed in four medium size pregnant bitches throughout two consecutive pregnancies and three small size pregnant bitches throughout one pregnancy, in order to determine the range of variation in the size of selected fetal structures throughout gestation. Formulae were derived to estimate the expected delivery date for both groups of bitches by measuring anatomical fetal structures, so that this method could be applied to a large number of different breeds. The determination of gestational age could be achieved with reasonable precision by selecting fetal structures. Prediction of parturition date was accurate to within one day by ultrasonographic measurement of the diameter of the gestational sac in early pregnancy and the biparietal diameter in late pregnancy in both small size breeds and medium size breeds.     

Effects of pre-natal glucocorticoids on testicular development in sheep

We tested the hypothesis that acute pre-natal exposure to high levels of synthetic glucocorticoid (betamethasone) would alter fetal testicular development through actions on gonadal glucocorticoid receptors (GRs). Pregnant Merino ewes bearing singleton male fetuses (n = 24) were allocated randomly among four equal groups to be injected intramuscularly with saline or betamethasone (0.5 mg/kg) either on day 109 of gestation or on both day 109 and day 116 of gestation. Fetal testes were collected at post-mortem, 5 days after each treatment. The volume of interstitial tissue and the volume, length and diameter of the sex cords were measured, and Sertoli cells and gonocytes were counted. For cord volume and interstitial tissue volume, control testes demonstrated maturational changes as fetal age advanced from 109 to 116 days of gestation. For that period, the single injection of betamethasone significantly reduced Leydig cell proliferation (P < 0.05), but had no effect on Sertoli cell numbers. Immunohistochemistry was used to localize GR and proliferating cell nuclear antigen in testicular cells. GR immunoexpression in Leydig cells was higher in fetuses exposed to betamethasone at 109 days of gestation than in control fetuses. Sertoli cells showed low levels of GR. It was concluded that, during mid-gestation, a brief period of glucocorticoid treatment could affect testicular development in male sheep fetuses. The mechanism probably involves direct effects on Leydig cells, as these cells express extra-GR in response to the treatment. Sertoli cells seem to produce less GR than Leydig cells, perhaps explaining their lack of response to betamethasone. These outcomes may have important implications for future fertility in male offspring.     

Early pregnancy diagnosis by means of ultrasonography as a method of improving reproductive efficiency in goats

Eighteen cyclic Shiba goats were used in this study. Estrus was synchronized with a single injection of 125 microg of a synthetic analogue of prostaglandin F(2)alpha (PGF(2)alpha) after detection of at least one corpus luteum by B-mode ultrasonography. Blood samples were collected from each animal on days 0, 7 and 21 post-mating for progesterone assay. Animals in estrus were either allowed to be mated by fertile bucks twice during estrus (group I; n=12) or not at all (group II; n=6). Ultrasonographic examinations were performed transrectally or transabdominally using a real-time B-mode scanner equipped with a 7.5 or 5 MHz transducer. All animals exhibited estrus 56.0 +/- 2.7 h after injection of PGF2alpha. The results show that the accuracy of the progesterone assay in diagnosing pregnancy on day 21 after mating was 80% for pregnancy and 100% for non-pregnancy, retrospectively. Ultrasonographic examinations showed that gestational sac and embryos heartbeats were detected on days 20.2 +/- 0.6 and 24.3 +/- 0.7 of gestation, respectively. Placentomes were detected on day 35.4 +/- 1.0 of gestation as small nodules (0.7 +/- 0.2 cm in size). At two months pregnancy, skeletal structures like skull, thorax and long bones were clear. Biparietal diameter of the skull and length of long bones could be used as an estimate of gestational age. The accuracy of detection of fetal number using real-time B-mode ultrasonography was 91.7% on day 60 of gestation. In conclusion, progesterone assay at day 21 post-mating (cut-off value, 1 ng/ml) can be used for pregnancy diagnosis in goats. However, B-mode transrectal ultrasonography was more efficient due to detection of embryo and confirmation of its viability by heartbeats. In addition, fetal number and gestational age could be determined only by ultrasonography.     

Ultrasonography of the reproductive tract and early pregnancy in red deer

Thirty-five farmed red deer hinds two years of age or older were observed during mating in April and May and the dates of oestrus and, or, matings were recorded. From immediately before the breeding season and at approximately weekly intervals from the start of mating until all deer were 42 days pregnant, rectal ultrasonographic scans were taken using a 5 MHz linear transducer while deer were held standing in a restraining device. Scans were recorded on video. The vagina and cervix were visible with the lumen appearing as a continuous or intermittent white line, respectively. The non-pregnant uterus was observed in most cases and was immediately anterior to the bladder. Structures resembling ovaries were seen only occasionally. By seven days gestation a 5 mm vesicle could be observed in a few deer, and by day 14, oedema of uterine horns was apparent in some cases. A comma-shaped fetal mass 6 mm long, fetal membranes and placentomes could be observed on day 24. The heart beat was observed on day 28 when the fetus was 10 mm long. Limb buds were observed on day 31 and by day 37 the head with nose and eyes was distinguishable. Fetal movements were first observed on day 42. The accuracy of pregnancy detection before day 20 was 35 per cent, between 21 and 30 days gestation 71 per cent and from 31 to 42 days 98 per cent.