Factors Affecting Dystocia in Cattle

The paper reviews the various factors affecting dystocia in cattle. It is based mainly on the recent studies found in the literature of the subject but refers occasionally to some older papers as well. The factors are grouped into four main categories: direct factors, phenotypic factors related to calf and cow, non-genetic and genetic factors. The first group includes malpresentations and uterine torsion. The second one includes: calf birth weight, multiple calvings, perinatal mortality, cow pelvic area, cow body weight and body condition at calving, gestation length. The non-genetic factors are: cow age and parity, year and season of calving, place of calving, maintenance practises, disorders, calf sex and nutrition. Other non-genetic factors are the level of hormones in the periparturient period, in vitro production of embryos and embryo cloning. Finally, the genotypes of cow, bull and calf, inbreeding, muscular hypertrophy, selection and quantitative trait loci form the fourth group of genetic factors.     

A study of 55 field cases of uterine torsion in dairy cattle

Two-hundred and seventy-three animals were enrolled in a case-case comparison of uterine torsions and other dystocias. The purpose of the study was to describe field cases of uterine torsion and their clinical management, compare them with other types of dystocia attended by field veterinarians, and evaluate the effect of season and housing on the incidence of torsions. Fifty-five cases of uterine torsions representing 20% of the dystocias were diagnosed. Most cases of uterine torsion were successfully corrected and followed by the vaginal delivery of a live calf. When compared with other types of dystocia, cows were at greater risk for uterine torsion than were heifers (OR = 5.2; P < 0.0001), while animals suffering from fetopelvic disproportion or carrying twins were at a lesser risk (OR = 0.05; P < 0.0001 and OR = 0.09; P = 0.007, respectively). Heifers had a lower risk when calving alone in a pen versus a tie-stall (OR = 0.2, P = 0.04). There was no significant effect of season on the risk of uterine torsion.     

母牛难产的风险病因--基于系列案例研究

[目的]难产是繁殖母牛的常见疾病,危害母牛和犊牛健康,进行难产牛原因分析有助于兽医或者牛场做好接产工作,提高生产力。 [方法]在万方数据服务平台、CNKI中国知网、Elsevier SD数据库和“SCI-科学引文索引”上,用关键词“难产”、“病例”、“牛”精确搜索我国相关的案例,统计筛除后的病例数,对牛难产原因进行统计和分析。 [结果]检索获得母牛难产的病例总数为753例,难产原因占比最大的是胎儿性难产有525例,占69.72%(95%CI 66.3-73.0);其次是产道异常（骨折造成骨盆畸形,子宫颈、阴道、阴门狭窄造成的产道异常）造成的难产89例,占11.82%(95%CI 9.6-14.3);阵缩及努责无力造成的难产41例,占5.44%(95%CI 3.9-7.3);子宫扭转造成的难产38例,占5.05%(95%CI 3.6-6.9);子宫颈开张不全造成的难产26例,占3.46%(95%CI 2.3-5.0);营养不良造成的难产18例,占2.39%(95%CI 1.4-3.8);双胎难产9例,占1.20%(95%CI 0.5-2.3);人为因素和其他因素造成的难产有7例,占0.93%（95%CI 0.4-1.9）。 [结论]引起母牛难产的最主要的因素是胎儿性难产、产道异常。兽医在实际临床中,应快速、准确确定母牛难产的病因,采取对应接产措施,减少经济损失。     

Uterine torsion of 720 degrees in a midgestation cow

A 720 degrees uterine torsion was diagnosed in a cow at 161 days of gestation. The uterine torsion was reduced by laparotomy and intra-abdominal manipulation. An emphysematous fetus was removed vaginally. The cow was treated medically for associated metritis and peritonitis. Uterine torsions in cattle most commonly occur at parturition and only rarely exceed 360 degrees.     

Cesarean section and ovariohysterectomy after severe uterine torsion in four cows

OBJECTIVE: To report a technique for intra-partum ovariohysterectomy (OVH) in cows after severe uterine compromise after uterine torsion. STUDY DESIGN: Clinical case report. ANIMALS: Four cows with uterine torsion. METHODS: After a ventrolateral cesarean section, uterine closure, and uterine detorsion, the laparotomy incision was elongated (20 cm) caudally so that the uterus can be completely exteriorized. The uterus was separated from broad ligaments by transection between 2 rows of overlapping interrupted sutures placed in the broad ligaments to a point approximately 2 cm caudal to the external os of the cervix. The vagina was occluded with 2 clamps directly caudal to the external os of the cervix and closed with 5 single cruciate sutures that penetrated all layers, and then the vagina was transected between the suture line and external os to remove the uterus. The abdominal incision was closed in layers. Results- All cows survived the surgery; however, 1 died the next day from Escherichia coli sepsis and 1 was euthanatized at 8 days because of unresponsive E. coli mastitis. One cow, 28 days after surgery developed a 15 cm perivaginal abscess, which resolved after drainage. This cow and the fourth cow survived and lactated. CONCLUSIONS: Intra partum OVH is technically possible after cesarean section in cows with uterine compromise or necrosis after uterine torsion. CLINICAL RELEVANCE: Ovariohysterectomy should be considered in cows with severe uterine torsion that have uterine tissue compromise to improve survival.     

Influence of uterine torsion in water buffaloes (Bubalus bubalis) with insights into the hematological and biochemical prognostic values regarding to manual correction

Bovine uterine torsion refers to the rotation of the gravid uterus around its longitudinal axis. It is the dominant cause of dystocia in buffaloes. A total of two hundred and seventeen dystocia’s Egyptian buffaloes were examined, and another twenty were apparently normal at the full term (healthy pregnant group). From the dystocia’s buffaloes, twenty-three percentage (n = 50) was uterine torsion after gynecology inspection at presentation (Ut group) and 5 days after the manual correction (Utc group). The buffaloes with uterine torsion exhibited loss of appetite, constipation, colic, and straining. The incidence of torsion was mostly at first parity that accounting for 50% of cases. Regarding to the pregnancy stage, torsion mostly occurred at full term, where it primarily occurred in buffaloes at 3 years of age. Right-sided torsion ensued in 90% of all cases. The survival rate of the pregnant buffaloes was 90% (45 buffaloes), and 10% (5 buffaloes) was directed to the culling. Regarding to the fetal survival outcome, 30% of fetuses was survived where the other 70% was died. The hematological results denoted leucocytosis in Ut and Utc groups that attributed to neutrophilia, monocytosis, and eosinophilia. Biochemical assessments were denoted an augments in the levels of serum AST, LDH, CPK, creatinine, blood urea nitrogen, progesterone, cortisol, MDA, NO, TAC, blood lactate (bLac), TNF-α, and IL-6. Where there were a non significant fluctuations in the ALT, GGT, calcium, and phosphorus levels in the torsion cases. The significant declines in 17-β-oestradiol, total proteins, albumin, magnesium, and GSH levels in the dams suffering from Ut were observed. The robust elevations in AST (156 ± 3.47) and bLac (16.12 ± 0.18) with severe hypomagnesaemia (2.69 ± 0.15) were evident in 10% of the torsion cases that directed to the culling. This can conclude that robust elevations in AST and bLac with severe hypomagnesaemia are factors denoting a poor prognosis for uterine torsion in the buffaloes.

     

The incidence of cervical dystocia and disorders of cervical involution in the post partum cow

The aim of this study was to obtain information on the frequency of cervical dystocia and involution disorders of the canalis cervicalis after difficult dystocia and to characterise factors possibly influencing these pathological conditions. Therefore 317 difficult births in the cow (extraction: 123; foetotomy: 82; caesarean section: 112) and the involution of the cervical canal were documented during the first ten days post partum. In total a cervical dystocia could be diagnosed 53 times (16.7% related to the total number of births). This kind of birth disorder is regularly followed by a caesarean section (p < 0.001). Animals who show a narrowness in the cervix were older than the cows without cervical dystocia (p < 0.05). The same correlation could be detected for the number of births. Animals with delivery problems associated with the cervix had already given birth to more calves than cows who were not affected by cervical disorders (p < 0.01). 58 cows developed a disorder of the cervical involution (18.3% related to the total number of deliveries). This puerperal disorder can be frequently observed after foetotomy (p < 0.001). A correlation between the incidence of disorders of cervical involution and the age or the parity of the animals could not be detected. In the same way, cows with a diagnosis of a cervical dystocia did not develop more frequently disorders of cervical involution than animals who showed a physiological dilation of the cervical canal intra partum.     

Discriminant analysis for predicting dystocia in beef cattle. I. Comparison with regression analysis

Data from 131 calvings of Chianina crossbred cows (2 to 5 yr old) bred to Chianina bulls were used to compare stepwise multiple regression analysis (RA) and stepwise, two-group discriminant analysis (DA) for predicting dystocia. Variables (21) studied in relation to dystocia included both prebreeding and precalving cow and calf effects. Calving was categorized as either unassisted or assisted without regard to the severity of dystocia. During this study, 30 (22.9%) assisted births occurred. All variables were standardized to a mean of zero and a variance of one before statistical analyses. Models were developed based on precalving variables and with both precalving and postcalving variables with both RA and DA. Average discriminant scores (centroids) were different (P less than .01) between assisted and unassisted cows. Significant precalving DA variables were cow age and precalving pelvic height. This model correctly predicted 26 of 30 (86.7%) of the occurrences of dystocia. Significant precalving RA variables were prebreeding pelvic width and precalving pelvic height. The amount of variation accounted for by these two factors was 31.5%. Calf birth weight, calf chest depth, calf height, precalving pelvic area, cow age and precalving cow weight were selected by DA for use in the combined precalving and postcalving prediction model. Calf birth weight was 58% more important than either pelvic size or cow age. Percentage correctly classified with this model was 87.4. Significant postcalving variables selected by RA in order of importance were prebreeding pelvic width, calf birth weight and calf shoulder width (R2 = .399).(ABSTRACT TRUNCATED AT 250 WORDS)     

Disorders of pregnancy

Ectopic pregnancy, uterine torsion, hypocalcemia, and hypoglycemia are discussed. A diagnostic and therapeutic approach to spontaneous abortion and embryonic death is given. Infectious causes of abortion are emphasized. Discussed are the normal variation in gestation length and its relationship to the diagnosis of dystocia as well as the diagnosis and treatment of dystocia.     

Using non-steroidal anti-inflammatory drugs around calving: maximizing comfort, productivity and fertility

Non-steroidal anti-inflammatory drugs (NSAIDs) have analgesic, anti-inflammatory, anti-endotoxic and anti-pyretic effects in cattle. As such, they could be expected to have significant effects in cows and calves in the post-calving period. This review evaluates the published data on the use of NSAIDs in the dam and its calf after dystocia, the impact of NSAIDs on uterine involution, the restoration of ovarian function and prevention and treatment of the metritis complex, and the benefits of using NSAIDs in the recumbent cow. Overall, the published data are very limited, despite frequent use of NSAIDs by veterinarians in the post-calving cow, and the small number of published studies focus on blanket treatment of calving cows rather than targeted treatment after dystocia. Blanket treatment had no economic benefit; indeed, some studies reported adverse effects, such as pyrexia and increased risk of metritis. There is even less information on the value of treating calves with NSAIDs after dystocia, despite significant tissue damage which may benefit from NSAID use. Appreciably more studies have evaluated the influence of NSAIDs on uterine and ovarian function, but clinical relevance is limited. In cows with a normal puerperium, prolonged treatment with NSAIDs may slow the restoration of normal function, but most reported studies are small and use NSAIDs more frequently and for longer periods than is common in general practice. The evidence of a clinical benefit in cows with puerperal disease is limited and equivocal, and the evidence base for the use of NSAIDs in the treatment of recumbent cows is also small, even though an expert panel concluded that NSAIDs were a key aspect of veterinary treatment of downer cows. The lack of evidence identified by this review supports the contention that NSAIDs are likely to be under-used and sub-optimally prescribed in the post calving period. Further research on the use of NSAIDs in the post-calving cow and calf is required.     

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.     

Physiological mechanisms controlling anestrus and infertility in postpartum beef cattle

Postpartum infertility is caused by four factors: general infertility, lack of uterine involution, short estrous cycles and anestrus. The general infertility component is common to any estrous cycle and reduces potential fertility by 20 to 30%. Incomplete uterine involution prevents fertilization during the first 20 d after calving but is not related to anestrus. Short estrous cycles prevent fertility during the first 40 d after calving by causing the cow to return to estrus before pregnancy recognition occurs. Anestrus is the major component of postpartum infertility and is affected by several minor factors: season, breed, parity, dystocia, presence of a bull, uterine palpation and carryover effects from the previous pregnancy as well as two major factors: suckling and nutrition. These major factors have direct effects on anestrus but also interact with one or more other factors to control postpartum anestrus. Physiological mechanisms associated with anestrus involve blockage of the GnRH "pulse generator" in the hypothalamus, but other pathways also must be involved because bypassing the pulse generator is not an effective treatment for all cows. The primary cause of anestrus probably is different for different stages of anestrus. The mediating mechanisms for anestrus are not involved with prolactin, oxytocin, the adrenal or direct neural input from the mammary gland but are at least partially involved with blood glucose and the endogenous opioid peptide system. Management options to decrease the impact of anestrus and infertility include: 1) restrict breeding season to less than or equal to 45 d; 2) manage nutrition so body condition score is 5 to 7 before calving; 3) minimize effects of dystocia and stimulate estrous activity with a sterile bull and estrous synchronization; and 4) judicious use of complete, partial or short-term weaning.     

皖北地区肉牛繁殖疾病调查与分析

[目的]旨在研究皖北地区肉牛能繁母牛繁殖疾病的发生情况。[方法]通过走访,并结合调查问卷,对皖北地区的22个母牛繁育场的3088头母牛的繁殖疾病发病情况及病因进行调查。[结果]结果显示：皖北地区母牛繁殖疾病以胎衣不下的发病率最高(5.99 %)、其次是子宫内膜炎(5.44 %)、难产(3.92 %)、流产(2.75 %)、子宫积脓(1.45 %)、阴道脱出(1.33 %)、卵巢囊肿分别(1.39 %)、持久黄体(1.52 %)。[结论]繁育场的饲养管理技术影响母牛繁殖疾病的发病率,针对这些因素提出了对应的改进意见,以期为安徽省的能繁母牛的扩拦增量工作提供决策参考。     

Patterns of stillbirth and dystocia in Ontario cow-calf herds.

The association between a number of individual animal and herd level factors and calving problems in beef cows and heifers were examined. Data were from the 1987 calving season for a subset of 123 herds which maintained individual-animal records, from a sample of 180 randomly selected Ontario cow-calf herds. The median herd dystocia rate was 5.8% and 24.4% of herds had no dystocias. The median herd stillbirth rate was 2.8%, and 33.3% of herds had no stillbirths. Dystocias and stillbirths were much more common in heifers than in cows. Separate statistical models of dystocia and stillbirth for cows and heifers were created. Dystocia in cows was associated with calf sex, previous calving assistance and large breed type and birth weight. Variations in 1987 cow herd dystocia rates were associated with calving season, location and density, and the herd dystocia rate in 1986. Dystocia in heifers was associated with large breed type and calf birth weight. Herd-level management practices associated with increased heifer dystocia rates included breeding heifers to calve earlier than cows and rearing heifers together with the cow herd. Stillbirths for both cows and heifers were associated with calving assistance, particularly hard assistance. Herd-level management and other factors were unassociated with stillbirths.     

Common Peripartum Problems in the Mare

Reproductive problems in the perinatal period can adversely affect a mare's future fertility or, worse, may be life threatening to her or her foal. A number of abnormalities can occur, including uterine torsion, uterine artery or uterine hemorrhage, retained fetal membranes, metritis, rectovaginal injuries, and necrotic vaginitis. Because hemorrhage, retained placenta, metritis, and necrotic vaginitis can happen after a normal delivery or after dystocia, all mares should be monitored closely in the first days after parturition for signs of lethargy, depression, colic, sore feet, or anorexia. Methods for diagnosing, managing, and treating these conditions and the possible complications are discussed.     

Dystocia in the bitch: A retrospective study of 182 cases

In a retrospective study of 182 cases of canine dystocia, no relationship was found between either breed or age and occurrence of dystocia. However, medium-sized breeds (between 12.7 and 20.5 kg bodyweight) were slightly over represented. Of the bitches that had whelped previously, 42 per cent had experienced dystocia. The dystocia was of maternal origin in 75.3 per cent of the cases, mainly due to uterine inertia, while 24.7 per cent were of fetal origin, mainly resulting from malpresentations/malorientations. The most common reason for dystocia was primary, complete uterine inertia (48.9 per cent) and 40 per cent of the bitches with this problem had small litters of one or two pups. The most common treatment was calcium and, or, oxytocin injection followed by a caesarean section. Digital manipulation including forceps delivery and, or, medical treatment was successful in only 27.6 per cent of the cases. Of the bitches studied, 65.7 per cent had a caesarean section. Pup deaths occurred in 52.2 per cent of the litters. Among bitches that had been treated within one to four-and-a-half hours after the beginning of second stage labour, 5.8 per cent of the pups died, whereas the corresponding value for bitches that had been treated between five and 24 hours after the beginning of second stage labour was 13.7 per cent. The total frequency of pup deaths was 22.3 per cent. These findings show that early diagnosis and prompt treatment are crucial in reducing the pup death rate in cases of dystocia.     

Use of postpartum vaginoscopic (visual vaginal) examination of dairy cows for the diagnosis of endometritis and the association of endrometritis with reduced reproductive performance

OBJECTIVE: To assess the association between the findings from vaginoscopic examination of postpartum dairy cows with peripartum reproductive disease and their subsequent reproductive performance, and to determine the factors that might be associated with a positive vaginoscopic examination (VV). METHODS: Cows (n=1325) from 17 seasonal calving dairy herds were enrolled if they had been calved at least 7 days and had at least one of the following conditions that placed them at risk of endometritis: retained fetal membranes (RFM), dystocia, a dead calf, hypocalcaemia, twin birth, calving induction or an observed vulval discharge (VD). Examination was undertaken 28-37 days before mating start date (MSD) within each herd. All cows were body condition scored (BCS) and were VV scored on a scale of 0 (clear) to 3 (purulent). The uterus and ovaries were assessed by rectal palpation. RESULTS: Cows with a positive VV score (1-3) were less likely to conceive to first service and had a lower pregnancy proportion than cows that had a negative VV score (score 0). Mean MSD to conception interval was longer in VV-positive cows. A positive VV score was associated with a low BCS, primiparity, intrapelvic uterus, poor uterine tone, large uterus, RFM, VD, dystocia, dead calf and twins. CONCLUSION: In the present study a positive VV score was associated with reduced reproductive performance and was more common in primiparous and low BCS cows. Of the at-risk cows, those with RFM, VD, dystocia, dead calf or twins were more likely to have a positive VV score.     

Uterine torsion followed by jejunal incarceration in a partially everted urinary bladder of a cow

A case of bladder eversion with intestinal entrapment in a cow is described. The condition occurred in conjunction with a 180 degrees right side uterine torsion. The cow responded well to corrective surgery.     

Discriminant analysis for predicting dystocia in beef cattle. II. Derivation and validation of a prebreeding prediction model

Discriminant analysis was utilized to derive and validate a model for predicting dystocia using only data available at the beginning of the breeding season. Data were collected from 211 Chianina crossbred cows (2 to 6 yr old) bred to Chianina bulls. A proportionally stratified sampling procedure divided females into an analysis sample (n = 134) on which the model was derived and a hold-out sample (n = 77) on which the prediction model was validated (tested). Variables available during the derivation stage were cow age, cow weight, pelvic height, pelvic width, pelvic area and calf sire. Dystocia was categorized as either unassisted or assisted. Occurrence of dystocia was 17.2 and 18.2% in the analysis and hold-out samples, respectively. All data were standardized to a mean of zero and a variance of one before statistical analysis. The centroid of cows experiencing dystocia differed (P less than .01) from that of cows calving unassisted in the analysis sample. Significant variables were pelvic area and cow age (standardized coefficients = .56 and .51, respectively). This model correctly classified 85.1% of the cows in the analysis sample. This was 13.5% greater than the proportional chance criterion. For model validation, prediction accuracy was 84.4% in the hold-out group, which was 14.2% greater than the proportional chance criterion. However, only 57.1% of the cows that experienced dystocia were correctly classified. Examination of the data revealed that those cows misclassified were 3 yr of age or older.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of uterine torsion on mare and foal survival: a retrospective study, 1985--2005

REASONS FOR PERFORMING STUDY: Anecdotal speculation suggests that prognosis for survival of mares and foals following correction of uterine torsion has improved over the past 30 years. OBJECTIVES: To determine statistically the outcome of uterine torsion according to duration of clinical signs, stage of gestation, parity, physical examination findings, method of correction, prognosis for survival and reproductive health of the mare, and prospects for the foal within the neonatal period. METHODS: This retrospective study combined cases from 4 equine referral hospitals. RESULTS: The stage of gestation at which uterine torsion occurred was a risk factor for survival of mare and foal. Overall mare survival was 53/63 (84%); when uterine torsion occurred at < 320 days gestation, 36/37 (97%) of mares survived compared to 17/26 (65%) survival rate when uterine torsion occurred at > or = 320 days gestation. Overall foal survival was 54% (29/54). When uterine torsion occurred at < 320 days gestation, 21/29 (72%) foals survived compared to 8/25 (32%) when uterine torsion occurred at > or = 320 days gestation. Thirty mares were discharged from the hospital carrying a viable fetus following uterine torsion correction and 25/30 (83%) of these mares delivered live foals that survived beyond the neonatal period. CONCLUSIONS: Prognosis for survival for mares and foals following uterine torsion is good and improves if torsion occurs < 320 days compared to > or = 320 days gestation. CLINICAL RELEVANCE: Gestational timing of uterine torsion should be considered when advising clients about the prognosis for survival of the mare and foal. The prognosis for a mare delivering a live foal is good if the mare is discharged from the hospital following uterine torsion correction with a viable fetus.