Periparturient diseases and their effect on reproductive performance in five dairy herds

The incidence of periparturient diseases and their effects on the calving to first service interval, the calving to conception interval and the mean number of services per conception were recorded in five Friesian-Holstein herds in the United Kingdom. The incidence rates of milk fever, milk fever followed by endometritis, retained fetal membranes, endometritis after retained fetal membranes, endometritis, or ovarian cysts, were 7.5, 1.4, 1.3, 3.3, 10.1 and 6.7 per cent, respectively, and the affected cows had significantly (P less than 0.05) extended calving to conception intervals (13, 66, 25, 51, 31 and 64 days, respectively) compared with herd-mates. Calving to first service intervals and services per conception were also adversely affected. In spite of treatment, milk fever, endometritis and ovarian cysts had a considerable impact on fertility. Improved methods of treatment and, or, prevention are clearly required.     

Incidence of subclinical endometritis and its effects on reproductive performance of crossbred dairy cows

In dairy cattle, uterine infections are not life threatening and often unavoidable; however, they reduce fertility and increase the production costs of properties. The aim of this study was to evaluate the incidence of subclinical endometritis from 32 to 70 days in milk (DIM) and its effects on the reproductive performance of crossbred dairy cows. Lactating cows (Holstein/Gir; n?=?172), with no history of retained placenta, without clinical signs of uterine infection were used. The body condition score (BCS) was evaluated on a scale from 1 to 5. Ultrasound examination was performed to evaluate uterine lining and ovarian activity, while vaginal mucus was analyzed by gloved hand. The diagnosis of subclinical endometritis was performed by endometrial cytobrush technique. The samples were collected, stained, and examined microscopically; positive cases for subclinical endometritis were considered with the presence of ≥5 % of neutrophils. Later, the cows were submitted to conventional artificial insemination or timed artificial insemination. The incidence of subclinical endometritis in the herd was 26 %, and this was not affected by the season of calving, presence of corpus luteum, DIM, and parity. Cows with a BCS ≤2.50 had a higher incidence of subclinical endometritis. The conception rate to first insemination and pregnancy rate at 150 days postpartum were not influenced by the presence of subclinical endometritis in crossbred dairy cows.     

Risk factors and the economic impact of ovarian cysts on reproductive performance of dairy cows in Korea

The objectives of this study were to determine the risk factors for development of postpartum ovarian cysts by evaluating several reproductive factors in individual cows, and to determine the economic impact of ovarian cysts on subsequent reproductive performance in dairy herds in Korea. The data, including cow parity, abnormal puerperium, endometritis, body condition score (BCS), and breeding status were collected from 634 cows in 9 dairy herds. We used logistic regression to evaluate the effects of these factors on ovarian cysts. A stepwise procedure, used to obtain the appropriate model with alpha=0.05, revealed that cow parity was the most important risk factor for ovarian cyst development within 8 weeks postpartum, while development of endometritis and BCS loss>or=1 from the dry period to 8 weeks postpartum were the most important risk factors for ovarian cyst development beyond 8 weeks postpartum. The occurrence of ovarian cysts beyond 8 weeks postpartum prolonged (P<0.01) the mean intervals from calving to first service (27 days) and conception (77 days), and increased (P<0.05) the culling rate (7.8%), while ovarian cyst development within 8 weeks postpartum did not affect (P>0.05) the mean intervals from calving to first service and conception or the culling rate. The economic loss resulting from the occurrence of ovarian cysts was estimated at approximately 823,996 won ($687) due to effects on the cost of nutrition, average growth of calves, labor and medical costs, and culling. These results suggest that cow parity is correlated with the development of ovarian cysts within 8 weeks postpartum, and endometritis and BCS loss>or=1 from the dry period to 8 weeks postpartum are correlated with the development of ovarian cysts after 8 weeks postpartum, which decreases reproductive performance and results in economic loss in dairy herds in Korea.     

Risk factors for delayed conception in Korean dairy herds

Delayed conception is defined as an interval of greater than 90 days postpartum before a cow becomes pregnant again. In this study, the risk factors for delayed conception in Korean dairy herds were determined by evaluating several reproductive factors in individual cows. The following data was recorded from 1,012 pregnancies in eight dairy herds (designated A-H) from July 2001 to June 2006: herd, cow parity, repeated animal (cows included 2, 3, or more times), calving season, calving condition (abnormal partus), postpartum disorders (retained placenta, metabolic disorders, metritis and ovarian cysts) and conception. Logistic regression was used to evaluate the effects of these factors on delayed conception. A stepwise procedure was used to obtain the appropriate model (α = 0.05), which revealed the herd, metritis and ovarian cysts to be significant risk factors for delayed conception. The odds ratio showed that the likelihood of delayed conception increased by 3.3 and 2.0 fold for each incidence of metritis and ovarian cysts, respectively. Delayed conception was significantly more likely in 2 herds, in herd A by 2.0 fold and in herd B by 2.4 fold, compared with herd H. These results suggest that the prevention of postpartum metritis and ovarian cysts, as well as improved herd management, will be needed to maintain a short interval between calving and conception in Korean dairy herds.     

Correlation between energy balance and fertility in Finnish dairy cows.

The effect of serum glucose, ASAT and urea on reproductive performance was studied in 45 Finnish dairy cows from 8 different herds. Blood samples were taken a month before calving as well as 2 weeks and 2 months after calving. Serum urea, ASAT and glucose were used as indicators of metabolic and energy balance. Glucose and ASAT concentrations were significantly correlated with fertility 2 weeks after calving, but not before calving or 2 months after calving. Antepartum, 60% of the cows had a low urea level; at 2 weeks and at 2 months postpartum 89% and 65%, respectively had low levels of urea. The cows were divided into groups as follows: low or high (greater than or equal to 2.9 mmol/l) glucose level and low or high (greater than or equal to 2.5 mmol/l) urea level. Low levels of glucose and/or urea in puerperium were associated with poor fertility. The intervals from calving to first insemination and conception were shorter in the group with high glucose and high urea than in the group with low values. The cows with the shortest intervals from calving to first insemination and conception showed adequate metabolic balance (high levels of urea and glucose). Clinical ketosis had an adverse affect on intervals from calving to first insemination and on conception. Intervals from calving to first insemination and to conception were significantly (p less than 0.01) longer in ketotic cows than in non-ketotic ones. Liver damage, reflected as elevated activity of ASAT, was associated with poor fertility. If shorter calving intervals are desired, adequate energy balance in puerperium is essential.     

Effect of prostaglandin treatment on the fertility of problem cows

Four autumn-calving dairy herds were selected to investigate the effect of an injection of prostaglandin in the period 14 to 28 days (mean 22 days) after calving on subsequent fertility. The cows were selected on the basis of having a condition likely to affect their fertility, including assisted calving, endometritis, retained fetal membranes, milk fever, cows with five or more lactations, cows having twins, or a combination of any of these conditions. They were assigned to treatment or control groups and paired as closely as possible on the basis of their condition and date of calving. Milk progesterone concentrations were measured on the day of treatment and then three and 10 days later. The trial ran for four months and involved 90 treated and 90 control cows. The combined data from all the animals in the trial failed to show any difference between the calving to conception interval, the first service conception rate or the numbers of services per conception of the treated and control groups. A Student's paired t test for groups of cows with a particular condition, both within individual herds and in all the herds, failed to show any significant effect of treatment (P greater than 0.05). Milk progesterone data showed that the presence of a corpus luteum did not influence the outcome of prostaglandin treatment. There was no evidence for excessive failure of luteolysis. It was concluded that there was no benefit in a routine injection of prostaglandin to dairy cows in the period 14 to 28 days after calving when re-breeding commenced more than 70 days after calving.     

Effects of Diseases on Reproductive Performance in Dairy Cattle Ⅱ: Reproductive Diseases

With the rapid development of dairy breeding and the scale feeding level,the average individual milk yield of dairy herds in China has been greatly improved over the last few decades.However,the reproductive performance of dairy cows,especially in high-producing dairy cows,has declined continuously and affected severely dairy farm profitability.Reproductive performance of dairy cows was influenced by many factors including environment,herd management,genetics and various diseases.It has become more evident that genital tract diseases(also known as reproductive diseases) decreased reproductive performance of dairy cows during the last 10 years.The effect of reproductive diseases on reproduction of dairy cows has received more attention.This paper briefly described the incidence of reproductive diseases such as metritis,various types of endometritis and retained fetal membrane and ovarian diseases such as ovarian cyst,persistent corpus luteum in China and abroad.This paper highlighted the effects of reproductive diseases on reproductive performance such as days open,calving interval,pregnancy rate,estrus detection,days to first breeding and breeding index.Moreover,we analyzed in more detail the possible mechanisms by disrupting endocrine signaling,damaging intrauterine environment and causing ovarian dysregulation.Lastly,we looked forward to the future research direction of reproductive diseases of dairy cows that provided data reference and theoretical support for improving the management measures of scale feeding,reducing the incidence of reproductive diseases,improving the production and reproductive capacity of dairy herds in China.     

疾病对奶牛繁殖性能的影响及其研究进展Ⅱ:生殖器官疾病

在过去几十年，随着奶牛育种和规模化饲养水平的快速发展，中国奶牛群单产水平大幅提高，但是奶牛，特别是高产奶牛繁殖性能呈现不断下降趋势，严重影响了奶牛养殖的盈利能力。繁殖性能的降低受多种因素影响，包括环境、畜群管理、遗传和各种疾病等。近年来，生殖器官疾病（也称繁殖疾病）降低奶牛生殖能力的情况越来越明显，其对奶牛繁殖的影响受到了越来越多的关注。文章简述了国内外生殖道疾病如子宫炎、子宫内膜炎、胎衣不下和卵巢疾病如卵巢囊肿、持久黄体等繁殖疾病发生情况。通过文献检索和数据比较，重点介绍了繁殖疾病对奶牛繁殖性能如空怀天数、产犊间隔、妊娠率、发情检出率、产后首次配种天数、配种指数等繁殖指标的影响和研究成果。同时，重点分析了繁殖疾病通过干扰生殖内分泌，损伤子宫内环境，导致卵巢功能异常影响奶牛繁殖性能的可能机制，并对奶牛繁殖疾病研究方向提出了展望，以期为改进中国规模牧场管理措施、减少繁殖疾病发生、提高奶牛群生产和生殖能力提供数据参考和理论支持。     

Fertility of dairy cows in Northern Ireland

A comprehensive database was established on the milk production and reproductive performance of dairy cows in 19 selected herds in Northern Ireland, varying in size, management system and genetic merit. Data were obtained for 2471 cows, 1775 of which calved in a second year, and 693 were culled from the herd for specific reasons. The estimated mean rate of heat detection (assessed by the interheat interval during the main breeding season) in all the herds was 71 per cent, with a range from 53 to 92 per cent The average conception rate to first insemination was 37.1 per cent (range 21 to 66 per cent). The average calving interval for the retained cows was 407.2 days (range 359 to 448 days). Twenty-eight per cent of the cows that calved were culled, with infertility being the largest single reason (26.8 per cent of the cows culled). There were major differences in reproductive performance between the herds, but heat detection rate, conception rate and calving interval did not appear to be affeded by a herd's genetic merit. The herds with shorter calving intervals were characterised by better heat detection efficiency (83 v 61 per cent, P<0.01), a shorter interval from calving to first insemination (74 v 97 days; P<0.05), a higher conception rate to first insemination (45 v 34 per cent, P>0.10) and a lower removal rate (23 v 37 per cent, P<0.01). Furthermore, the cows in these herds had lower body condition scores (BCS) in the dry period (3.0 v 3.3; P<0.05) but lost less body condition in early lactation (0.3 v 0.6 BCS units, P<0.05). These results show that dairy herd fertility in Northern Ireland is generally low and similar to that previously reported for England and the USA, but that in some herds changes in herd management practices improved the cows' fertility.     

Risk factors for postpartum endometritis and the effect of endometritis on reproductive performance in dairy cows in Korea

The objectives of this study were to determine the risk factors for postpartum endometritis by evaluating several reproductive factors in individual cows, and to determine the effect of endometritis on the subsequent reproductive performance in dairy herds in Korea. The data, including health status, parity and body condition score (BCS) of cows, and calving date, were collected from 320 cows in eight dairy herds calving from January 2001 to October 2002. We used logistic regression to evaluate the effects of these factors on endometritis. A stepwise procedure, used to obtain the appropriate model with alpha=0.05, revealed that retained placenta, metabolic disorders and parity are the important risk factors for endometritis. The mean intervals from calving to first service and conception were prolonged (P<0.01) by 23 and 36 days, respectively, in the endometritis group compared to the non-endometritis group. The first service conception rate was lower (P<0.05) in the endometritis group (47.6%) than in the non-endometritis group (62.6%). The number of services per conception was higher (P<0.05) in the endometritis group (1.9) than in the non-endometritis group (1.6). We conclude that retained placenta, metabolic disorders and cow parity are strongly correlated with the development of postpartum endometritis, which decreases reproductive performance in dairy herds in Korea.     

Epidemiological Description of Cystic Ovarian Disease in Argentine Dairy Herds: Risk Factors and Effects on the Reproductive Performance of Lactating Cows

To describe the epidemiology of cystic ovarian disease (COD), to find possible risk factors associated with the incidence of cysts and to analyse the impact of COD on the reproductive performance of dairy cows, databases from 22 dairy herds from the main dairy region in Argentina were retrospectively evaluated throughout a 3‐year period (2009–2011). A total of 248 COD cases over 9156 parturitions were recorded, resulting in a cumulative incidence rate of 2.7%. Cystic ovarian disease incidence density was lower during the first 100 days post‐partum (DPP) than during later stages of lactation. Seasonality had a significant influence on the disease presentation with higher incidence rates during winter and spring. Cows with a previous diagnosis of clinical mastitis showed 2.72 times more chances of developing ovarian cysts. Cystic cows had longer calving to first service and calving to conception intervals and lower conception rate than controls.     

Body Condition Change Ante- and Postpartum, Health and Reproductive Performance in German Holstein Cows

The effects of body condition score (BCS) change and status ante‐ and postpartum (pp) on health and reproductive performance in 234 German Holstein cows from eight dairy farms were evaluated. BCS was determined from 6 weeks antepartum until 20 weeks pp in 2‐week intervals. Three and 5 weeks pp progesterone concentrations in blood serum were determined to detect the presence of luteal tissue as an indicator of cyclicity. The incidence of various diseases, percent cycling cows, reproductive measures and culling rate were assessed. Data were subjected to logistic regression to account for possible herd and lactation number effects. Cows with a low BCS status (<3.0) at calving and during early lactation (4–10 weeks pp) were at a higher risk of suffering from lameness (OR 2.9–9.4), not being cycling at 3 and/or 5 weeks pp (OR 2.24–3.99) and being culled (OR 2.56–2.79) than cows in better body condition (≥3.0) In addition, cows with a low BCS status at parturition were at a higher risk of developing endometritis (OR 2.95) and becoming pregnant later than 105 days pp (OR 5.92) than cows with a BCS ≥ 3.0. At 10 weeks pp, the risk of dystocia (OR 4.10) or retained placenta (OR 2.78) at the preceding calving and not being pregnant at 200 days pp (OR 2.42) was higher in cows with a BCS < 3.0 than with a BCS ≥ 3.0. Cows with no BCS loss antepartum were more likely to have an interval from calving to first artificial insemination of <80 days and <105 days open, to be cycling at 3 and 5 weeks pp and to be pregnant at 200 days pp than cows with a BCS loss of >0.25 (OR 2.44–6.67). Furthermore, cows with no BCS loss from calving to 4 weeks pp had a lower risk of suffering from displaced abomasum than cows with a slight or a severe BCS loss (OR 0.09–0.07 respectively). In conclusion, our results suggest that body condition loss during the antepartal period affected BCS status at parturition and to a certain extent during lactation which was linked to a higher incidence of reproductive disorders and lameness, a higher culling rate and lower reproductive performance.     

Reproductive performances of dairy cows in smallholder production system in Selalle, Central Ethiopia

A study was conducted to assess the reproductive performance and factors that influence reproductive efficiency of cows in smallholder dairy farms in Selalle, Central Ethiopia. Three hundred dairy farms (average herd size = 8) were visited and data on reproductive, breeding and management histories were collected and analysed. The overall geometric means for calving to conception interval (n = 382) and duration after last calving (n = 422) were 187 and 201 days in pregnant and non-pregnant cows, respectively. The least-squares mean calving to conception interval was higher (p < 0.05) in mixed crop–livestock production (MCLP) than in small urban dairy production (SUDP) systems and was lower (p < 0.01) in non-suckling than in suckling cows. District significantly influenced (p < 0.01) the least-squares mean duration after last calving and, among the districts, non-pregnant cows in Wuchale-Jida had the highest values, whereas cows in Sululta and Mulo had the lowest values. The overall average number of services per conception (±SD) and the first service conception rate were 1.6 ± 1.0 (n = 382) and 56% (n = 456), respectively. The prevalences of abortion, dystocia (assisted parturition), retained fetal membrane, vulval discharge/endometritis and pre-weaning calf mortality were 1.4%, 1.3%, 5.4%, 2.8% and 17.4%, respectively. The present estimates of extended calving to conception interval and duration after last calving indicate poor reproductive performances of cows in Selalle smallholder dairy farms. The pre-weaning calf mortality rate is highly significant. Accordingly, a further detailed investigation is necessary to identify and quantify the specific reproductive disorders and associated interacting factors attributing to such poor performance and to determine the causes and predisposing factors behind such high calf mortality.     

Effects of feeding rumen-protected choline on incidence of diseases and reproduction of dairy cows

The objectives of this study were to determine the effects of feeding rumen-protected choline (RPC) to dairy cows on the incidence of disease in early lactation, and on their fertility as measured by return to ovarian cyclicity and pregnancies per insemination (P/AI). In the first experiment, 369 cows were fed 15 g/day of RPC between 25 days pre-calving and 80 days post calving. In the second experiment, 578 primigravid cows were fed 15 g/day of RPC for the last 21 days of gestation only. In both experiments, P/AI were evaluated for the first and second inseminations, and health disorders were monitored daily until 90 days after calving. Return to cyclicity was evaluated in experiment 1 only, on days 51 and 61 post calving. In the first experiment, feeding RPC reduced the incidence of clinical ketosis, mastitis, and morbidity, and the number of cases of mastitis per cow. Feeding RPC did not influence cyclicity and P/AI. In the second experiment, cows fed RPC tended to have greater morbidity than controls because of an increased incidence of metritis and fever, although the incidence of retained fetal membranes was lower. The P/AI for first and second inseminations were similar between treatments. Supplementing the diets of dairy cattle with RPC from before until after calving improved the health of early lactation cows. However, in primigravid cows feeding RPC before calving only had mixed effects on health. Feeding RPC had no beneficial effects on reproduction in either experiment.     

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)     

Ovarian Cyclicity and Reproductive Performance of Holstein Cows Carrying the Mutation of Complex Vertebral Malformation in Japan

This study was carried out on 71 lactating Holstein Friesian cows to investigate the resumption of ovarian cyclicity postpartum and the reproductive performance in cows carrying the mutation of complex vertebral malformation (CVM) compared with control ones. The cows were distributed in two dairy farms in Hiroshima Prefecture, Western Japan. Blood samples were collected from the cows to detect carrier cows with CVM mutation. Furthermore, plasma samples were collected weekly after calving from control cows (n = 10) and CVM carrier cows (n = 10), until 10 weeks postpartum to investigate the day of first ovulation and the resumption of ovarian cyclicity postpartum. The reproductive parameters were investigated and compared with control and CVM carrier cows. Thirty‐six cows were diagnosed to be CVM carriers by DNA examination and confirmed later by DNA sequencing. The pedigree analysis of the carrier cows revealed that they were daughters of six types of CVM carrier semen that still was used in dairy farms in Western Japan. In terms of reproductive indices, there were no significant differences between the control and the CVM carrier cows on the day of the first ovulation postpartum and the interval from calving to first insemination. However, CVM carrier cows significantly required more inseminations per conception and showed a significantly longer period to conception and subsequent calving than control ones. In conclusion, the reproductive performance of the CVM carrier cows was lowered through conception failure that might indicate the occurrence of intra‐uterine mortality in those cows.     

The Effect of Seasonal Thermal Stress on Lipid Mobilisation,Antioxidant Status and Reproductive Performance in Dairy Cows

Heat stress is a major factor contributing to low fertility of dairy cows with a great economic impact in dairy industry. Heat‐stressed dairy cows usually have reduced nutrient intake, resulting in a higher degree of negative energy balance (NEB). The aim of this study was to investigate the seasonal thermal effect on lipid metabolism, antioxidant activity and reproductive performance in dairy cows. Thirty‐two healthy dairy heifers were included in the study. According to the ambient temperature, animals were divided into two groups: winter (N = 14) and summer season (N = 18). Metabolic parameters, paraoxonase‐1 (PON1) activity and total antioxidant status (TAS) were monitored at the time of insemination (basal values) and from 1 week before until 8 weeks after calving. Number of services per conception and calving‐to‐conception (CC) interval were calculated from the farm recording data. Serum triglyceride, non‐esterified fatty acids (NEFA) and beta‐hydroxybutyrate (BHB) concentrations were significantly increased after calving in summer compared to winter, indicating higher degree of NEB in cows during summer. PON1 activity was significantly decreased after calving in both summer and winter group. TAS concentration was significantly lower in summer than that in winter. A significantly higher number of services were needed for conception in summer compared to winter, and CC interval was significantly longer in summer than that in winter as well. Additionally, reproductive performance significantly correlated with the severity of NEB, suggesting that lipid mobilization and lower antioxidant status contributed to poor reproduction ability in dairy cows during hot months.     

Effects of application in spring of urea fertiliser on aspects of reproductive performance of pasture-fed dairy cows

AIMS: To assess if raising concentrations of crude protein (CP) in pasture in spring by the frequent application of urea fertiliser would affect ovarian follicular dynamics, luteal function, onset of oestrus and reproductive performance of dairy cows under farming conditions in New Zealand. METHODS: Spring-calved dairy cows were grazed for 101 days in paddocks that were either not fertilised (Control; n=20) during the course of the study, or were fertilised with 40-50 kg nitrogen (N)/ha every 4-6 weeks (High-N; n=20). Similar generous pasture allowances were offered to both groups. Concentrations of CP in pasture, urea in serum and progesterone in milk were measured. Ovarian follicular and luteal dynamics were determined using ultrasonography. Oestrous behaviour and the number, time and outcome of inseminations were also recorded. RESULTS: Mean concentrations of CP in pasture and urea in serum was higher in the High-N than the Control group (25.2 vs 21.6 and 8.3 vs 5.4 mmol/L for CP and urea, respectively; p<0.001). Intervals between calving and first oestrus, first insemination and conception, the time of first emergence of a dominant follicle, milk progesterone concentration, and the diameter of the corpus luteum (CL) in the first luteal phase did not differ significantly between groups. The interval from calving to first ovulation tended (p=0.10) to be lower and the diameter of the dominant follicle of the oestrous cycle at which cows conceived was greater (p=0.02) in Control than High-N cows. CONCLUSIONS: The use of large amounts of urea fertiliser during spring and the consequent increases in concentrations of CP in pasture and urea in serum did not negatively affect any of the parameters of reproductive performance of pasture-fed dairy cows that were assessed in this study.     

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.     

Investigation on the Distribution and Analysis on Formation Cause of Cystic Ovarian Disease in Dairy Cows

In order to explore the incidence,pathogenic factors and the formation mechanism of cystic ovarian disease (COD) in Beijing scale dairy farm,we used the rectal examination and ultrasound diagnosis,combined with the dairy parity,calving season and serum biochemical indices and hormone levels to investigate the distribution,influencing factors and formation cause of cow ovarian cysts.The results showed that the incidence of cystic ovarian disease (COD) was 10.73% in the testing dairy herds and the incidence of COD was associated with the parities.The incidence rate of ovarian cyst in the cows calving in the summer (51.06%) was higher than those calving in the spring (8.51%) and winter (17.02%).Insulin,IGF-1 and E₂ were closely related with the formation of the cow ovarian cyst.The average concentrations of serum insulin and IGF-1 in cows with ovarian cysts were significantly lower than those of normal cows(P < 0.05),but the average concentration of serum E₂ was significantly higher than that of normal cows(P < 0.05).This study provided reliable basis for the prevention and treatment of cow ovarian cyst.