母羊难产的处理

母羊难产指分娩过程发生困难，不能将胎儿顺利地由阴道排出体外，难产多由阵缩无力、胎位不正、子宫颈狭窄及骨盆狭窄等原因造成。     

母猪难产的诊疗体会

母猪在分娩过程中,超出了一定的分娩时间,不能将胎儿顺利地排出体外,叫难产。发生难产的原因有母体和胎儿两方面的因素,包括产力性难产、产道性难产和胎儿性难产。     

羊的难产及助产方法

孕期满,胎儿发育成熟,母体将胎儿及其附属物从子宫排出的这一生理过程称为分娩。分娩过程是否顺利,取决于产力、产道和胎儿三方面因素,如果这三个因素发生异常,不能使胎儿顺利娩出,就会使分娩过程受阻或延长,这一现象称为难产。据发生难产的因素,可分为产力性难产、产道性难产(     

母猪难产的病因病机与预防诊治

难产又称异常分娩,轻则胎儿窒息死亡,重则母猪和仔猪全部死亡。如果难产过程中对生殖器官造成损伤,会影响母猪分娩后身体的恢复,易发生子宫炎、乳房炎和无乳症等疾病。母猪难产,不仅仅影响当前胎次生产性能,还可能持续影响之后的繁殖性能,甚至发生过难产的母猪失去种用价值,不得不被提前淘汰。     

对两头难产奶牛助产的体会

难产，是牛（特别是舍饲奶牛）常见的产科疾病。由于产力、产道和胎儿3方面因素中任意一种发生异常，使胎儿不能排出，就会使分娩过程受阻，造成难产。往往外界的扰乱及错误的干预，可使顺产变为难产；而本来发生的难产，如果进行及时的诊断和助产，则可以防止难产的发生。在难产过程中，如处理不及时或处理不当，可能造成母畜及胎儿死亡．既便母畜存活下来，也常诱发生殖器官疾病，导致以后不育。     

浅谈孕犬难产

在犬病临床上，孕犬自然分娩从产程开始(即第一次出现宫缩)，到10h以上仍未能分娩的情况为难产。难产的发病原因较为复杂，通过这些年对我室难产病例的分析，各类难产的发生可因孕犬品种，胎儿体况以及外界因素的影响而各不同。一般地说，短头品种犬比头长品种犬易发生难产：初产犬比经产     

母犬常见的繁殖疾病及其诊治

母犬常见的四类繁殖性疾病有:难产、假妊娠、卵泡囊肿和子宫炎。难产包括异常分娩或分娩困难;假孕多见于犬,猫很少发生;犬卵泡囊肿将导致其长时间分泌雌激素,表现为“慕雄狂”,但屡配不孕;子宫炎是产后子宫感染所致。1难产难产的原因涉及母体因素(阵缩微弱、产道狭窄)和(或)胎儿因素(胎儿过大和胎位异常)。某些品种的动物更常发生难产。最近一项调查结果表明,拳师犬难产的发生率高,主要是由于阵缩微弱,也有胎位不正性难产。有下列情形之一的可确定难产:(1)有难产或生殖道阻塞史;(2)直肠温度下降到37.7℃以下24h内仍未发生分娩;(3)强烈努责持续1-2h后仍未见犬产出;(4)主动分娩持续1-2h,仍未见犬产出;(5)在主动分娩过程中,母犬休息超过4-6h以上;(6)在分娩过程中,母犬有明显的疼痛。如嚎叫、舔或啃咬外阴部;(7)异常的阴道排泄物。如在产出胎儿前,阴门流出血液或墨绿色液体,表明胎盘已经剥离。     

母猪难产的诊治方法

分娩过程是否正常,取决于产力、产道和胎儿三个因素。这三个因素是相互适应、相互影响的,如果其中任一因素发生异常,使正常的分娩过程受阻,就会造成难产。对母猪难产的病因及种类进行了分析,提出了几种助产方法,即人工助产、药物助产,剖腹产术等;同时介绍了母猪难产的预防方法,即加强母猪饲养管理,加强运动,适时配种做好产前检查,分娩时用科学的方法助产等。     

母牛分娩的助产及难产处理技术

母牛在分娩过程中，胎儿不能顺利产出称为难产。难产不仅会引起犊牛损伤或死亡，而且易使母牛子宫和产道受损及感染，轻则影响母牛的生产性能、造成不孕，严重时可危及母牛生命。因此，在母牛分娩时应密切注意观察，判明难产原因，适时予以救助。     

拉布拉多犬难产病例3则

犬的分娩过程址否顺利，往往取决卜产力．产道和胎儿的胎位胎式是否正常。如果其中任何一个或一个以上的因素发生异常，即可影响分娩的正常进行，称之为“难产”。     

A comparative study on behavioral,physiological, and adrenal changes in buffaloes during the first stage of labor with normal and difficult parturition

The present study was primarily carried out to trace the behavioral, physiological, and adrenal changes during the first stage of labor in cases of dystocia, either in parturient buffalo heifers or cows, and their clinical significance. Of the 118 investigated buffalo herds, 40 cows (dystocia = 20 and eutocia = 20) and 40 heifers (dystocia = 20 and eutocia = 20) were used in this study. Cows approaching actual birth were transferred to a calving box with straw bedding. Behavior of the studied animals was recorded from the time that the animal was moved to the calving box until the emergence of the fetal limbs in the vulval lips. If no progress in parturition was observed within two hours after the rupture of fetal sacs (end of the first stage), these cases were considered as suffering dystocia. As the fetal limbs emerged from the birth canal, animals were examined clinically to determine their average pulse and respiratory rates as well as body temperature. Blood samples were collected to determine the cow/heifers cortisol level. Results of the present study indicated that dystocia was accompanied by disturbed physiological status and cortisol levels. Practical monitoring system of parturient animals, through observing behavioral, physiological, and adrenal aspects during calving, should be regarded to expect dystocia and provide help for the animal in the appropriate time.     

Endocrine changes in late bovine pregnancy with special emphasis on fetal well-being

During late bovine pregnancy, several hormones are involved to maintain and develop a successful result with a live calf. These hormones are e.g., progesterone, high levels during the whole pregnancy period, originating from the corpus luteum, maternal adrenals and placenta. Oestrone sulphate, oestrone in its conjugated form, shows elevated levels from about mid-pregnancy until the third stage of parturition (expelling of the fetal membranes). For the onset of normal parturition and the parturition process as such, a change from progesterone to oestrone synthesis is crucial. The increasing levels of oestrone are time-related to an increased synthesis of prostaglandin F(2alpha) (reflected as elevated levels of 15-ketodihydro-PGF(2alpha)) causing prepartal luteolysis and several hormones are then involved in the labour process such as prostaglandin F(2alpha), cortisol and oxytocin. Cortisol might also be an indicator of stressful events for the dam. Levels of pregnancy associated glycoproteins (PAGs), originating from the trophoblastic binucleate cells, are increasing during the last 10 days prior to parturition. All the mentioned hormones have certain functions during pregnancy, more or less understood. However, could deviations from the expected profiles during late bovine pregnancy indicate impaired fetal well-being or be of importance for reproductive performance during the postpartum period? Abortions, stillbirths or dystocia are situations where endocrine profiles might predict the status of the calf. There are two possible approaches to study the endocrine changes in late pregnancy-to follow spontaneous cases of normal or impaired pregnancies or to experimentally disturb the gestation or induce parturition. We have in one study followed pregnant animals to depict reproductive disturbances, both animals with expected normal parturitions and animals where the sire of the calf has given rise to a high incidence of stillborn calves. The number of stillborn calves or dystocia has been small and so far it has not been possible to obtain a clear picture of the usefulness of endocrine parameters to follow fetal well being, but some of the hormonal parameters show a deviating profile. In a small group of animals with induced parturition (PGF(2alpha)), two out of three had parturition problems and one of these animals had a stillborn calf. All three animals had retained fetal membranes. It was possible to demonstrate a deviating endocrine profile in the cow having the stillborn calf in the sense of higher levels of progesterone, cortisol and 15-ketodihydro-PGF(2alpha) at the time of parturition. In both animals with dystocia the levels of oestrone sulphate after parturition were more sustained. Increasing and high levels of PAGs were only demonstrated in the animal with a normal parturition. These studies are ongoing, aiming at finding changes in endocrine profiles related to impaired pregnancies.     

肉牛难产主要因素分析

难产(dystocia)是母畜分娩时胎儿娩出缓慢或难以娩出,需要助产帮助胎儿娩出的过程。难产既会导致母牛出现生殖道疾病而影响其后的发情和繁殖,也会危及犊牛和母牛的生命,严重损害养牛经济效益。引起肉牛难产的因素很多,有遗传因素和非遗传因素,包括母牛因素、胎儿因素、公牛因素、营养因素与环境因素等。犊牛出生重、母体骨盆结构和妊娠时长是3个最主要的因素。多种因素的交叉互作,使难产成为极其复杂的生理与病理现象。国际牛业发达国家非常重视母牛繁殖与生产环节,开展了大量卓有成效的研究与分析。在对几十年来有关肉牛繁殖与生产方面的报道较为细致分析基础上,文章重点对普通肉牛繁殖与生产过程中出现的主要难产问题进行综述,供国内同行借鉴。     

Effects of twinning on postpartum reproductive performance in cattle selected for twin births

The effects of twinning, dystocia, retained placenta, and body weight on postpartum reproduction were evaluated for 3,370 single and 1,014 twin births. Females were bred by AI for 40 d followed by 20 or 30 d of natural service with equal numbers bred and calved in spring and fall. Percentage of dams cyclic by the end of the AI period was lower (P<.05) for dams birthing and nursing a single calf (92.4%) than for dams birthing twins and nursing zero (98.7%) or two (94.7%) calves. Whereas the interval from parturition to first estrus was shorter (P<.01) for dams birthing and nursing a single (56.9 d) than for dams birthing twins and nursing one (68.5 d) or two (69.6 d) calves, length of the interval was further reduced by dystocia in nonlactating dams of either twins or singles (type of birth x dystocia, P<.05). Ensuing pregnancy rates were also affected by type of birth and dystocia. Without dystocia, dams birthing and nursing a single calf had a higher pregnancy rate (79.2%) than dams birthing twins and nursing one (61.7%) or two (66.3%) calves, whereas the lower ensuing pregnancy rates associated with dystocia in dams of singles (71.9%) resulted in similar rates among dams of singles and twins with dystocia (type of birth x dystocia; P<.01). Having a retained placenta resulted in a lower incidence of (93.5 vs. 96.4%, with vs. without; P<.05) and a longer interval to (64.7 vs. 59.2 d; P<.01) estrus while reducing subsequent pregnancy rates (X = 9.6%) in 3 of the 7 yr evaluated (retained placenta x year, P<.01). Because all parous females were bred during the same calendrical period, the shorter gestation length for twin calves (275.6 vs. 281.3 d) resulted in a longer interval from parturition to conception for twin births, whereas means for conception date differed by only 2 d between dams of twins and singles. Furthermore, a reduction (P<.01) in the interval to conception occurred with dystocia in dams of singles (89.3 vs. 85.0 d, without vs. with dystocia) and of twins nursed by zero (116.9 vs. 83.5 d), one (100.2 vs. 92.8 d), or two (96.1 vs. 97.2 d) calves. Another detriment to fertility was the higher incidence of fetal mortality or abortions associated with twin vs. single pregnancies (12.4 vs. 3.5%; P<.01). However, despite the lower conception rates for dams of twins, the increased prolificacy provides an opportunity to increase total beef production with a twinning technology.     

Observations on dystocia in a romney flock

The mating and lambing records for 1964–1972 of a Romney stud that had been experiencing a serious dystocia problem were investigated. Until 1970 between 20 and 31% of ewes required assistance at lambing but this level then fell to 18% in 1971, 11% in 1972, 3.3% in 1973 and 4.0% in 1974. The decline in dystocia evident in the latter years of the investigation is considered to have been brought about largely by the culling of ewes that were repeatedly assisted at parturition and by the selection of rams that sired lambs of lower birth weight.

Dystocia in this flock was highly correlated with the mean birth weight of single lambs ( r =0.84, p<0.01). Fifty nine percent of assisted single lambs were males; ram lambs were heavier at birth than ewe lambs. Apart from the year 1966, primiparous ewes required no more assistance than older ewes and, except for that year, ewes bearing singles required the same levelof assistance as those bearing twins.

An effect of the sire on the incidence of dystocia was demonstrated for four of the eight lambings studied and was related to the birth weight of the lambs. Thirty four percent of ewes that had been assisted to lamb once had to be assisted again the following year as compared with a 16% assistance rate necessary for those ewes that had not been helped at the previous lambing, thus establishing a high level of repeatability for the condition (p<0.001).     

Twinning in cattle: III. Effects of twinning on dystocia, reproductive traits, calf survival, calf growth and cow productivity

An evaluation of natural twinning in beef cattle revealed that cows birthing twins had shorter (P less than .01) gestation lengths, more (P less than .01) retained placentas, more (P less than .01) dystocia, more (P less than .01) days to estrus, lower (P less than .01) conception rates and more (P less than .01) days to pregnancy than cows birthing singles. Days to estrus, conception rate and days to pregnancy were not affected by number of calves reared (1 vs 2) in cows birthing twins. Survival at birth was greater (P less than .01) for single- than for twin-born calves, but twins and singles did not differ (P greater than .05) in postnatal survival. When dystocia was experienced, calf survival at birth was 95% vs 73% for singles vs twins compared with 99% vs 92% when no dystocia was experienced. Calves born twins were lighter (P less than .01) at birth, 100 d and 200 d, but twins and singles did not differ in postweaning gains. Total calf weights at 100 d per cow calving were 12% greater (P less than .01) in cows birthing twins vs singles when twin calves reared by foster dams were excluded. The potential increase in cow productivity for total calf weight at 100 d is 40% if calf survival rates of twins with dystocia relative to survival rates of twins without dystocia were comparable to survival rates of singles with and without dystocia, and if cows birthing twins were fed and managed to obtain conception rates equal to those of cows birthing singles. Identification of cows gestating twins to provide for their higher prepartum nutritive requirements and calving assistance at parturition is necessary to make twinning in cattle an economically viable technology.     

Peripartal hormonal changes in Alpine goats: a comparison between physiological and pathological parturition

In this study, 31 pregnant Alpine does were used to investigate the peripartal plasma profiles of progesterone, estradiol-17β, 15-ketodihydro-PGF(2α) and cortisol, assessing differences between goats with physiological and pathological parturition. The goats were observed around the time of parturition; all peripartum abnormalities were recorded, and veterinary assistance was provided if necessary. Blood samples were collected every 12 h from 7 days before to 7 days after delivery, and plasma used for hormonal analysis by radioimmunoassay. Two animals died during the study, and their data were excluded from the study. Of the remaining 29 animals, 23 goats had a spontaneous and physiological delivery, while six goats showed pathological parturition, including dystocia and retained placenta. The 65 alive kids were viable at birth and at 7 days of age. The results concerning the hormonal concentrations in the normal parturition confirm and define more precisely the patterns already described in the goat, while the comparison between physiological and pathological parturition has never been previously reported in this species. Highest peripartum levels of cortisol were found in the pathological group at delivery (30.6 vs 15.9 ng/ml) (p<0.01) and 12 h later (26.2 vs 11.1 ng/ml) (p<0.05); the greater cortisol concentrations found in goats with dystocia and retained placenta could suggest a higher level of stress. No significant differences between the two groups were found with respect to the circulating values of the other hormones, but the individual variability and the small number of goats enrolled in the pathological delivery group could have masked possible differences.     

Investigations about kind and frequency of mechanical dystocia in ewes with special regard to the vaginal prolapse ante partum

The incidence of dystocia from ewes in nine lambing periods (1992-2000) was recorded at an obstetrical clinic. First we analysed parturition difficulties in normal pregnant sheep (group 1, n = 229). In the second group parturitions of ewes with vaginal prolapse ante partum were investigated (n = 129). In group 1 maternal causes of dystocia occurred more often than fetal ones (50% maternal, 45% fetal). In maternal parturition difficulties ringwomb was the dominating reason (64%), while abnormal presentations, position and/or posture of the lambs occurred most frequently in fetal dystocia (67%). But there was no statistical influence of age and number of parturitions in both groups. The average of the first notice of prolapsed vaginal tissue was 11 days before lambing. There was a predominance in the affection of sheep at first and second pregnancy (52%). Only 26% of the group 2 sheep had a spontaneous delivery. In 58% of the cases a dystocia was diagnosed. A preterm caesarean section had carried out in 12%, five ewes died before parturition because of septicemia (4%). Sheep suffering from vaginal prolapse ante partum showed maternal caused dystocia significant more frequently than members of group 1 (p < 0.001), with ringwomb as dominating reason (70%). The number of born lambs was significant higher in group 2 than in group 1 (p = 0.019).     

Body condition and dislocated abomasum: comparative investigations into back fat thickness and additional criteria in cattle

The body condition, the kind of parturition, the milk yield and diseases during early lactation were investigated in 228 cows including heifers. Overconditioning (back fat thickness > 30 mm) before parturition resulted in cows falling ill with mastitis and abomasal displacement (DA). These cows mobilised the most fat in comparison with healthy cows and cows suffering from different diseases after parturition. Especially heifers (83%) which gave birth to heavier male calves fell ill with DA, therefore needed assistance during labour because of dystocia. Besides DA additional disturbances occurred in those heifers, e.g. 50% mastitis, and 30% retentio secundinarum in this investigation. The daily milk yield amounted to 13.1 kg in cows with DA and to 23 kg in healthy cows. The presented results support the classification of DA into the fat mobilisation syndrome. Consequently overconditioning and stress during parturition need to be avoided to prevent DA.     

STUDIES ON DYSTOCIA AND BIRTH WEIGHT IN ANGUS HEIFERS CALVING AT TWO YEARS OF AGE

A trial is described in which groups of Angus heifers mated as yearlings were maintained on two widely differing nutritional levels during the last third of gestation in order to study effects on birth weight of calves and dystocia. The different nutritional levels produced a 5 lb difference in birth weight of calves (P < 0.01). As the calving season advanced the mean calf birth weight increased by 1.4 lb every ten days (P < 0.01). Heifers that suffered dystocia had calves 7 lb heavier and pelves 15.6 sq cm smaller than heifers calving normally (P < 0.01). Following observations on the birth process it was concluded that uncomplicated birth is complicated within two hours following the appearance of the amniotic sac.