Occurrence Of Endometritis Research Articles

Exosomal miR-433 regulates the secretion of inflammatory factors in endometrium epithelial cells of dairy cows with endometritis

Endometritis is a common postpartum reproductive system disease, which causes reproductive disorders and even infertility in dairy cows. High-throughput sequencing revealed that exosomal miR-433 is differentially expressed in the peripheral blood of dairy cows with endometritis. However, the specific roles of miR-433 in the occurrence and development of endometritis in dairy cows are still unclear. Therefore, a miR-433-labeled probe was used initially and found that miR-433 is mainly located in uterine cavity epithelial cells and stromal cells. The fluorescence expression of miR-433 in the uterine cavity epithelium and stromal tissues of dairy cows with endometritis is significantly weaker than that in the healthy tissues. The qRT-PCR results showed that the expressions of miR-433 in the uterine tissues of dairy cows with endometritis, LPS stimulated endometrial epithelial cells (EECs), and their derived exosomes were significantly lower than those in the uterine tissues of healthy dairy cows, EECs and their derived exosomes. Exosomal miR-433 derived from EECs transports into neighboring LPS-stimulated EECs by exosome vesicles fusion, regulating the secretion of inflammatory factors within the endometrial epithelium of dairy cows with endometritis, further influencing the development of endometritis. In conclusion, the intensity of miR-433 expression decreased in the epithelial and stromal cells of the uterine lumen and exosomes derived from endometrial epithelium in dairy cows during the occurrence of endometritis, which to some extent promotes the development and progression of endometritis in dairy cows.

The results of studying the contents of the uterus in endometritis of cows

The etiological factor in the occurrence of endometritis should be considered pathogenic and conditionally pathogenic microflora that penetrates into the uterus if the rules of asepsis and antiseptics are not followed. Bacterial contamination of the uterine cavity occurs more often in cows after calving or artificial insemination. The presence of clinical endometritis depends on the balance between microbes, the body’s resistance and a number of other factors. To study the uterine contents in endometritis in cows, the samples of N.A. Flegmatov, V.S. were used. Dyudenko and Katerinova, as well as the species composition of microorganisms and their sensitivity to antibiotics were determined by the disco diffusion method. The results of the research showed that the microflora of the contents of the uterus is mainly represented by bacteria of the E. coli group, opportunistic microflora and pathogenic fungi more sensitive to ciprofloxacin and levofloxacin.

Do Calving-Related Injuries of the Vestibulum Vaginae and the Vagina Affect the Reproductive Performance in Primiparous Dairy Cows?

The aim of this study was to investigate the influence of calving-related injuries of the vestibulum vaginae and the vagina on fertility measures in heifers. German Holstein heifers (n = 236) were checked for vestibulum vaginae and vaginal injuries. These were scored according to localization, depth and length. The healing process was assessed until day 42 post partum. Calving ease and the occurrence of metritis and endometritis were evaluated. In 160 heifers, the following fertility measures were calculated to assess the reproductive performance of heifers: mean interval from calving to first insemination, mean days open, mean interval from first insemination to conception, mean calving interval, mean pregnancy index, percentage of animals pregnant at 200 days p.p., and first service conception rate. On the one hand, dystocia was a risk factor for injuries of the soft birth canal, and, on the other hand, those injuries were a risk factor for metritis and endometritis. In this study, calving-related injuries of the vestibulum vaginae and the vagina had no statistically significant effect on the reproductive performance of heifers. One reason for this outcome was probably the overall good healing tendencies of those injuries in heifers.

Polymorphism Evaluation of TLR2 Gene Associated with Endometritis Infection in Buffalo Reared in Egypt

Background and Aim: Toll-like receptors (TLRs) are important for the recognition of pathogen-associated molecular patterns. Single nucleotide polymorphisms (SNPs) within TLRs have a potential impact on the alteration of susceptibility or resistance to inflammatory diseases. This work focused on a case-control study for the distribution of SNPs in TLR2 gene to test their role for endometritis occurrence in river buffalo.
 Materials and Methods: Egyptian buffaloes from the slaughterhouse were tested, where forty samples divided into apparently healthy uteri (20n) and clinically infected ones (20n) were used to detect the genetic association between TLR2 gene SNPs and endometritis disease.
 Results: Nineteen novel polymorphic sites were identified. Three SNPs were found to be statistically significant. AA genotype at 5`UTR and CC genotype at the coding region had significant association with susceptibility to endometritis, while GG genotype at 5`UTR had significant association with resistance to endometritis. Polyphen 2 analysis revealed three amino acids substitutions in TLR2 protein having potential functional significance. Haplotype reconstruction revealed the statistical significance of haplotype frequencies between cases and controls indicating its association with the occurrence of endometritis.
 Conclusions: It is to be concluded that the innate immune activation response may be interfered by the effect of polymorphisms and mutations of TLRs due to the reduction of the protein ability to recognize Pathogen associated Molecular pattern (PAMPs).

Effects of Intrauterine Infusion of Micronised Purified Flavonoid Fraction (MPFF) in Metritis-Diagnosed Dairy Cows Naturally Infected by E. coli during the Early Postpartum.

Simple SummaryThe occurrence of early metritis (EM) in dairy cattle causes serious economic losses. The treatment effectiveness for EM is highly controversial. Antibiotics administered by intrauterine infusions have been extensively used to control the growth of aerobic and anaerobic bacteria. Flavonoid glycosides (FGs) are polyphenolic naturally derived compounds considered to have many health-related properties such as antibiotic, anti-inflammatory, phlebotonic, and several vascular-protecting activities. Although FGs have been used for several therapies in humans, there is an increasing interest in investigating PGs for other therapeutic purposes. The objective of the present study was to investigate an alternative treatment for EM based on FG intrauterine infusions during the early postpartum period in dairy cows. FG administration contributed to the onset of uterine and cervix involution, bacteriological and immunological control, and fertility improvement associated with highly dose-specific responses during the early postpartum period in EM-positive dairy cattle.The occurrence of metritis during the postpartum period causes serious economic losses in dairy cattle. The Micronised Purified Flavonoid Fraction (MPFF) is a polyphenolic flavonoid compound which is considered to have many health-related properties such as antibiotic, anti-inflammatory, phlebotonic, and several vascular-protecting activities. The aim was to evaluate the effects of a new strategic therapy for metritis based on MPFF intrauterine infusions during the early postpartum in dairy cows naturally infected by Escherichia coli. The clinical effects on reproductive anatomical structures and chronological involution dynamics were monitored until day 24 postpartum by ultrasonography. Moreover, uterine bacteriological and cytological (polymorphonuclear neutrophils; PMNs) profiles were analysed before and after MPFF infusion. The results showed that the success rate (% cure) at day 24 postpartum was improved significantly when using higher MPFF doses (p < 0.05). Moreover, MPFF treatment acutely diminished the size of the cervix and uterus and improved the involution process during the first 24 days (p < 0.05). The prevalence of pathogenic bacteria found in in vitro cultures was significantly variable (p < 0.01), as were the antibiotic sensitivity patterns. Pathogenic bacteria isolates decreased after MPFF applications in a dose–response fashion (p < 0.01), while isolates obtained from controls and low-dose-MPFF-treated animals were stable and similar (p > 0.05). The sensitivity patterns of pathogenic bacteria isolated in in vitro cultures from MPFF-treated animals were variable, although resistance to E. coli, Staphylococcus aureus, Bacillus spp., and coliforms was shown irrespective of the MPFF doses used. However, MPFF-treated cows showed a dose–response effect regarding PMN rates (p < 0.05). The calving-first service, calving–conception interval, and conception rate improved significantly from using higher MPFF doses (p < 0.05). In conclusion, this study shows that MPFF treatment differentially affects uterine involution, bacteriological profiles, cytological traits, and reproductive performance in metritis-positive dairy cows naturally infected by E. coli.

Enhanced Expression of miR-34a Enhances Escherichia coli Lipopolysaccharide-Mediated Endometritis by Targeting LGR4 to Activate the NF-κB Pathway.

Background Persistent endometritis caused by bacterial infections has lethal effects on the reproductive performance of dairy cattle, which compromises animal welfare and delays or prevents pregnancy. The microRNA (miRNA) miR-34 family plays a pivotal role in the inflammatory process; however, the precise mechanism of miR-34a in endometritis has not been thoroughly elucidated to date. Methods In this study, the endometrium of cows diagnosed with endometritis was harvested for bacterial culture and Gram staining to evaluate bacterial contamination of the uterus. Based on this, a bovine endometrial epithelial cell (BEND) inflammation model and a mouse model stimulated with lipopolysaccharide (LPS) in vitro and in vivo were constructed. Cell viability was assessed by CCK-8, trypan blue staining, and flow cytometry. H&E was applied to histopathological analysis. Immunohistochemical, immunofluorescence, qRT-PCR, and western blot assays were performed to measure the mRNA and protein expression of relevant genes. Online databases, plasmid construction, and dual-luciferase reporter gene assays were used to predict and validate the interaction between miR-34a and its target gene LGR4. Finally, mice were injected vaginally with a local antagomir to validate the role of miR-34a in murine uterine inflammation. Results In this study, we observed that Gram-negative bacteria, represented by Escherichia coli, are the predominant pathogenic agents responsible for the recurrent occurrence of endometritis in dairy cows. Further, miR-34a was found to repress the expression of LGR4 by targeting the 3′ untranslated region (3′UTR) of LGR4. miR-34a was upregulated in bovine uterine tissues and bovine endometrial epithelial cells stimulated with LPS. miR-34a induced the release of the proinflammatory cytokines IL-1β, IL-6, and TNF-α by activating the phosphorylation of NF-κB p65. Furthermore, IL-1β upregulated miR-34a transcription and downregulated LGR4 expression in an IL-1β-dependent manner. Conclusions Taken together, our study confirmed that miR-34a is regulated by IL-1β and suppresses the level of the LGR4 3′UTR, which in turn exacerbates the inflammatory response. Thus, the knockdown of miR-34a might be a new direction for the treatment of endometritis.

Association of uterine fluid metabolites with the occurrence of metritis in dairy cows

Metritis is highly prevalent (10-30%) in dairy cows leading to decreased reproductive performance and economic losses. Recent studies demonstrated that aerobic and anaerobic bacteria are present in the uterine lumen of all cows immediately after parturition. Although the etiology of uterine diseases is mainly attributed to bacterial infection, bacterial contamination alone is not sufficient for the development of metritis. Reduced immune function and impaired regulation of inflammation are other components in the pathogenesis of metritis. Therefore, the objective of this study is to investigate the association of the uterine fluid biomarkers at the day of calving and metritis incidence within the first 2 weeks postpartum. We hypothesize that a disturbed uterine fluid metabolic landscape at the day of calving contributes to the development of metritis in dairy cows.

Microflora in the Reproductive Tract of Cattle: A Review

There are microbial communities in and on the bodies of all multicellular organisms, and this microbiota can have a significant impact on the biology of the host. Most studies have focused on the microbiome of the skin, mouth, and gut, whereas relatively little is known about the reproductive microbiome. From the perspective of the bovine reproductive tract, uterine diseases such as metritis and endometritis are traditionally viewed to result only from interactions occurring between the host animal and pathogens originating from either the environment or ascension from the vagina. This outdated opinion has been refuted by recent advanced studies that propose that, in addition to bacteria colonization through the extrinsic and ascending pathways to the vagina, bacteria can also move from the gut to the uterus, which is also associated with reproductive tract disorders. This has led to the concept of the “endogenous route hypothesis”, which has vital inferences for comprehending the etiology of metritis and endometritis. Furthermore, it has opened up the possibility of developing new prophylactic and therapeutic agents as alternatives to antimicrobial agents. In addition, the unveiling of next-generation sequencing technology makes it more convenient to perform detailed sequencing and analysis of data on the cervical, vaginal, and uterine flora and to further study uncultured bacteria in these niches—most importantly, the cervical niche, which previously was thought to have lower bacterial complexity. Research conducted to date has proven that the composition of microflora in a community varies widely between environmental sites, host niches, and health status. Furthermore, it has also been suggested that the occurrence of endometritis in the dairy and beef cattle reproductive tract is neither casual nor indirect but multifactorial. Whether disturbance in the variety of the microflora in the reproductive tract (dysbiosis) has a role in determining the sensitivity to metritis and endometritis is not yet known. This article outlines the current progress in understanding the microflora with regards to the bovine reproductive tract. The compositions of microflora in various niches of the reproductive tract are briefly elucidated. In addition, the functional role of these microflora communities in the reproductive tract is discussed, with particular emphasis on the association of bacterial flora with reproductive disorders and failures. Finally, prophylaxis and therapeutic approaches based on the new comprehension of the effects of antimicrobials, probiotics, and bacteriophages on the composition of the reproductive tract microflora are also considered.

Effect of age at first calving and heat stress at parturition on reproductive efficiency and postpartum disorders in Holstein heifers

The objective of this study was to evaluate the impact of age at first calving (AFC) and climatic conditions at calving on peripartum disorders and reproductive performance in Holstein heifers in a hot environment. A total of 3000 reproductive records from a large highly technified dairy farm were used; the variables evaluated were temperature humidity index (THI; &lt;77, 77-83, &gt;83) at calving and AFC (&lt;2.0, 2.0-2.2 and &gt;2.2 years). Across age groups, the cases of dystocic parturition increased (p&lt;0.05) when the deliveries occurred with severe heat stress (4.3% vs. 3.3% for THI &gt;83 and &lt;83 units, respectively). Across THI, conception rate at the first postpartum artificial insemination (AI) was lower (p=0.02) for heifers calving for the first time &gt;2.2 years compared to heifers calving between 2.0 and 2.2 and &lt;2.0 years (9.8, 15.3 and 13.7%, respectively). Conception rate at first AI postcalving was higher (p&lt;0.01) in heifers calving with THI less than 83 units than in heifers calving with a THI &gt;83 units (16.8 vs. 5.4%). The conception rate considering all services was affected (p&lt;0.05) by AFC (42.7, 50.4 and 40.9% for AFC &lt;2.0, 2.0-2.2 and &gt;2.2 years, respectively). The interaction AFC × THI at calving was significant (p&lt;0.05). The occurrence of metritis was higher (p&lt;0.05) in heifers &lt;2.0 years of age at calving than those calving after 2 years of age. The presence of ovarian cysts was less common (p&lt;0.05) in heifers with greater AFC. In conclusion, increasing the AFC in Holstein heifers had no benefits in reproduction and health, compared with heifers calving at &lt;2.0 years. These data in a hot climate suggest that heifers should be selected to begin their first lactation before 2 years of age.

Impact of endometritis on post-partum ovarian cyclicity in dairy cows

Endometritis in dairy cows is a major global issue and has been associated with a decrease in reproductive performance. The aim of this study was to quantify the effect of endometritis (as defined by the presence of any abnormal vaginal discharge after 21 days post-partum) on post-partum ovarian cyclicity in dairy cows. Milk progesterone analysis was used to monitor reproductive cyclicity in 170 dairy cows across three different commercial herds. Associations between the occurrence of endometritis and the incidence risk of a variety of atypical cycle profiles during the calving to conception period were investigated to establish the importance of endometritis on post-partum ovarian activity.Endometritis increased the incidence odds of atypical ovarian profiles (P < 0.05) with prolonged luteal activity being the most affected (P < 0.05), but also showed prolonged time (3 days) to onset of luteal activity after parturition (P < 0.05). Using milk progesterone analysis, we found a relatively low incidence odds for reproductive cycle problems in healthy cows during the calving to conception period. However, the incidence odds of cycle problems, in particular prolonged luteal activity, were high in cows that had experienced endometritis, which would have significantly impaired reproductive function.

Bacterial contamination hypothesis: a new concept in endometriosis.

BackgroundEndometriosis is a multifactorial disease that mainly affects women of reproductive age. The exact pathogenesis of this disease is still debatable. The role of bacterial endotoxin (lipopolysaccharide, LPS) and Toll‐like receptor 4 (TLR4) in endometriosis were investigated and the possible source of endotoxin in the pelvic environment was examined.MethodsThe limulus amoebocyte lysate test was used to measure the endotoxin levels in the menstrual fluid and peritoneal fluid and their potential role in the growth of endometriosis was investigated. Menstrual blood and endometrial samples were cultured for the presence of microbes. The effect of gonadotrophin‐releasing hormone agonist (GnRHa) treatment on intrauterine microbial colonization (IUMC) and the occurrence of endometritis was investigated.Main findings (Results)Lipopolysaccharide regulates the pro‐inflammatory response in the pelvis and growth of endometriosis via the LPS/TLR4 cascade. The menstrual blood was highly contaminated with Escherichea coli and the endometrial samples were colonized with other microbes. A cross‐talk between inflammation and ovarian steroids or the stress reaction also was observed in the pelvis. Treatment with GnRHa further worsens intrauterine microbial colonization, with the consequent occurrence of endometritis in women with endometriosis.ConclusionFor the first time, a new concept called the “bacterial contamination hypothesis” is proposed in endometriosis. This study's findings of IUMC in women with endometriosis could hold new therapeutic potential in addition to the conventional estrogen‐suppressing agent.

Counts of bovine monocyte subsets prior to calving are predictive for postpartum occurrence of mastitis and metritis

The heightened susceptibility to infectious diseases in postpartum dairy cows is often attributed to immune dysfunction associated with the transition period. However, the cell populations involved in this immune dysfunction and the dynamics between those populations are not well defined. Monocytes play a crucial role in governing initial immune response in bacterial infections. Bovine monocytes are subdivided in classical (CD14+/CD16−), intermediate (CD14+/CD16+) and non-classical monocytes (CD14−/CD16+) with distinct phenotypic and functional differences. This study investigated the relationship of monocyte subsets counts in blood at 42 and 14 days prior to expected calving date to occurrence of metritis and mastitis within 2 weeks postpartum. In the enrolled prospective cohort of 27 German Holstein cows, housed at the Institute of Animal Nutrition of the Friedrich-Loeffler-Institute Braunschweig, Germany, n = 13 developed metritis and/or mastitis postpartum. A multivariable logistic regression was used to analyze the relationship between prepartum cell counts of monocyte subsets and neutrophils with postpartum disease. Our model revealed that higher counts of the two CD14+ monocyte subsets were predictive of disease. In contrast, higher numbers of the CD14− monocyte subset were negatively associated with disease. Interestingly, the neutrophil count, a common hallmark for inflammatory response, was not associated with the outcome variable at either time point. The results indicate that the number and composition of monocyte subsets before calving are related to the susceptibility to infectious disease within 2 weeks postpartum. Furthermore the oppositional effect of CD14+ and CD14− subsets strengthens the hypothesis that these subsets have different functional roles in the inflammatory response in dairy cows.

A longitudinal cohort study of acute puerperal metritis cases in Swedish dairy cows.

BackgroundAcute puerperal metritis affects cows during the early postpartum period and causes fever, fetid vaginal discharge and general depression. The disease is severe and treatment with antimicrobials is often required. This study followed 79 Swedish dairy cows with acute puerperal metritis with registered treatment and outcome in terms of recovery. Bacteria isolated from the uterus and their susceptibility to penicillin were studied. Clinical cases were assigned by participating practitioners who examined the cows, performed uterine swab sampling, decided treatment and provided information about cow health and calving conditions. Fertility and culling data were collected from the official Swedish milk and health recording scheme. Recovery from disease was defined in four levels; as a cow that survived 1 or 4 months, was inseminated and subsequently became pregnant. Intervals from dates of first and latest calving to insemination date were studied.ResultsThe most common bacterial findings were a mixed culture of Escherichia coli and bacteria such as Gram positive cocci, Fusobacterium necrophorum, Clostridium spp. or Trueperella pyogenes. The Gram positive cocci, Pasteurella spp. and F. necrophorum were generally susceptible to penicillin. The majority of cows (70%) were treated with penicillin in accordance with the Swedish policy on treatment of metritis while 19% were treated with tetracycline and 8% were not treated with antimicrobials. Recovery rates were similar between treatments. Besides “calving to last insemination” interval (CLI) that was 5 days shorter than the national mean, fertility was slightly reduced compared to national means. “Calving to first insemination” interval (CFI) was 4 days longer than national mean and number of inseminations/cow increased from 1.9 to 2.1. Escherichia coli culture positive cows did not become pregnant to the same extent as cows without E. coli in the uterus (P = 0.046). Twin births resulted in a longer CFI (P = 0.034). The culling rate was generally high (42% within 300 days after occurrence of metritis), though death associated with acute disease was low (6%).Conclusions Escherichia coli was the most common bacterial pathogen isolated from cases of acute puerperal metritis in the present study. This bacterium is inherently resistant to penicillin, but although most cows were treated with penicillin, death due to acute disease was low and recovery and final fertility results were acceptable. In times of emerging antimicrobial resistance and demand for prudent antimicrobial use, we suggest that penicillin is a “good enough” choice if antimicrobial treatment of acute puerperal metritis is needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s13028-016-0257-9) contains supplementary material, which is available to authorized users.

Extended lactation in high-yielding Holstein cows: Characterization of milk yield and risk factors for lactations >450 days

Two data files consisting of 3278 (one herd) and 4393 lactations (three herds) were used to characterize milk production of high-yielding Holstein cows milked three times per day and experiencing extended lactations (up to 1399 days) in a hot environment. Additional objectives were to identify risk factors for the occurrence of extended lactations, to assess the association between lactation length and milk yield and to determine the conception rates of cows with extended lactations and with multiple services. Thirty percent of lactations were between 450 and 1399 days. Lactation yield of cows with lactations >900 days was over 30,000kg. Average daily milk yield from 305 to >450 days in milk was 29.9 and 31.9kg for primiparous and multiparous cows, respectively. The epidemiological analysis of risk factors for extended lactations using a multiple variable logistic regression indicated that ketosis (OR=1.4), peak milk yield (<50 vs >50kgd−1, OR=1.4), temperature-humidity index at 60 days postpartum (<82 vs >82 units, OR=1.4), retained placenta (odds ratio (OR)=1.5), 305-d milk yield (<11,000 vs >11,000kg, OR=1.6) and the occurrence of metritis (OR=1.8), significantly increased the risk for lactations >450 days. Primiparous cows had less than half the risk of extended lactations (OR=0.3) compared to multiparous cows. Conception rate in cows with extended lactations decreased as number of services increased (conception rate=50.5% for 4 services and 13% for ≥14 services). The data showed that well-managed Holstein cows milked three times daily were capable of lactating for over 1200 days with remarkably high persistency and with high milk yield at drying-off. Reproductive and metabolic disorders associated with calving were important risk factors for extended lactations.

Molecular detection of intrauterine microbial colonization in women with endometriosis

ObjectiveIncreased intrauterine microbial colonization by bacteria culture method and occurrence of endometritis have been reported in women with endometriosis. Here we investigated microbial colonization in intrauterine environment and cystic fluid of women with and without endometriosis by molecular approach. Study designThis is a case-controlled biological study with a total of 32 women each with and without endometriosis. Among them, 16 each in these two groups of women received treatment with gonadotropin-releasing hormone agonist (GnRHa). Pattern of microbial colonization in endometrial swabs and endometrioma/non-endometrioma cystic fluid was examined using broad-range polymerase-chain reaction (PCR) amplification of bacteria targeting 16S rRNA gene (rDNA). After quantification of index PCR product, 16S rDNA metagenome sequence analysis was done by Illumina Miseq system. ResultsA wide proportion (0.01–97.8%) of multiple bacteria was detected in both endometrial swabs and cystic fluid collected from women with and without endometriosis. 16S metagenome assay indicated that proportion of Lactobacillacae was significantly decreased (p<0.01) and of Streptococcaceae, Staphylococaceae, Enterobacteriaceae was significantly increased (p<0.05 for each) in GnRHa-treated women with endometriosis than in GnRHa-untreated women. While bacteria culture method failed to detect a single colony, 16S metagenome assay could detect significantly higher percentage of Streptococcaceae (p<0.01) and Staphylococaceae (p<0.05) in the cystic fluid derived from women with ovarian endometrioma comparing to that in cystic fluid collected from non-endometrioma cysts. ConclusionThese findings indicate the occurrence of sub-clinical infection in intrauterine environment and in the cystic fluid of ovarian endometrioma. Additional side effect of GnRHa treatment in promoting silent intrauterine and/or ovarian infection should be considered.

Consequences and economics of metritis in Iranian Holstein dairy farms

The objectives of this study were (1) to describe the risk factors, incidence, and productive and reproductive consequences of metritis in dairy cows, and (2) to estimate the financial losses associated with metritis using data gathered from 4 Holstein dairy farms in Isfahan, Iran. Calving records from March 2008 to December 2013, comprising 43,488 calvings, were included in the data set. The effects of metritis on productive and reproductive performance were analyzed using a mixed linear model for primiparous and multiparous cows separately and in an overall data set (all cows combined), whereas risk factors on metritis incidence were examined using a multivariable logistical regression model for the overall data set. The incidence of metritis per cow per year was 13.2% on average and ranged from 9.0 to 15.8%. Results of logistic regression analysis demonstrated that calving year, parity number, calving season, twinning, dystocia, and retained placenta were significantly associated with the occurrence of metritis, whereas previous metritis incidence did not show an association. Greatest odds of metritis occurred in first-parity cows that calved in winter and had retained placenta, twinning, and dystocia in recent years. A case of metritis significantly reduced the 305-d milk yield in primiparous and multiparous cows and overall, but had no significant effects on 305-d fat and protein percentages in either primiparous or multiparous cows. Overall, a case of metritis reduced 305-d milk yield by 129.8±41.5kg/cow per lactation. The negative reproductive effects due to metritis were smaller and nonsignificant for primiparous cows compared with multiparous cows. Overall, a case of metritis increased days open and number of insemination per conception by 16.4±1.2 and 0.1±0.0 per cow per lactation, respectively. Among the individual farms, metritis costs ranged from $146.4 to $175.7 with a mean of $162.3/case. The model to calculate metritis costs proposed here could be used to estimate economic losses for metritis in other developing countries, where farm productive and economic data are generally scarce.

A mixed methods inquiry into the validity of data

BackgroundResearch in herd health management solely using a quantitative approach may present major challenges to the interpretation of the results, because the humans involved may have responded to their observations based on previous experiences and own beliefs. This challenge can be met through increased awareness and dialogue between researchers and farmers or other stakeholders about the background for data collection related to management and changes in management. By integrating quantitative and qualitative research methods in a mixed methods research approach, the researchers will improve their understanding of this potential bias of the observed data and farms, which will enable them to obtain more useful results of quantitative analyses.Case descriptionAn example is used to illustrate the potentials of combining quantitative and qualitative approaches to herd health related data analyses. The example is based on two studies on bovine metritis. The first study was a quantitative observational study of risk factors for metritis in Danish dairy cows based on data from the Danish Cattle Database. The other study was a semi-structured interview study involving 20 practicing veterinarians with the aim to gain insight into veterinarians' decision making when collecting and processing data related to metritis.Discussion and EvaluationThe relations between risk factors and metritis in the first project supported the findings in several other quantitative observational studies; however, the herd incidence risk was highly skewed. There may be simple practical reasons for this, e.g. underreporting and differences in the veterinarians' decision making. Additionally, the interviews in the second project identified several problems with correctness and validity of data regarding the occurrence of metritis because of differences regarding case definitions and thresholds for treatments between veterinarians.ConclusionStudies where associations between specific herd health management routines and disease outcome variables are drawn based purely on quantitative observational studies may benefit greatly by adding a qualitative perspective to the quantitative approach as illustrated and discussed in this article. The combined approach requires, besides skills and interdisciplinary collaboration, also openness, reflection and scepticism from the involved scientists, but the benefits may be extended to various contexts both in advisory service and science.

Reproductive performance in the subsequent lactation of dairy cows previously treated for failure to be detected in oestrus

AIM: To describe the effect of treatment of cows not detected in oestrus (NDO) with progesterone (P4) and oestradiol benzoate (ODB) in one lactation, on the reproductive and productive performance in the subsequent lactation. METHODS: Cows (n=770 from nine herds) which were NDO 10 days before the planned start of the seasonal breeding programme (PSM) were blocked by herd, age (2 or >2 years old) and ovarian status (i.e. with or without a palpable corpus luteum; CL), and treated either with an intravaginal progesteronereleasing device and ODB and resynchrony, or were left as untreated controls. In the following lactation, data were collected on the occurrence of endometritis, NDO, breeding dates, pregnancy test results and milk production. The effect of treatment and ovarian status in the previous lactation on the incidence of disease, and the proportions submitted for service, conceived and pregnant in the subsequent lactation were analysed. Calving dates and intervals from start of breeding to first insemination and conception were analysed using Kaplan Meier survival analysis. Additional multivariate analyses were undertaken to include known confounders such as age, breed, herd, calving date and milk production, as well as the cyclic status (i.e. previously cycling, NDO, or ‘late-calving’) in the previous lactation, to examine the potential ‘carryover’ effects of previous status on the reproductive performance in the subsequent lactation. RESULTS: Treatment of NDO cows resulted in an earlier calving date (Julian calving date 214, 95% CI=207–221, vs 224, 95% CI=220–228; p=0.005), more female calves reared (31.4% vs 23.3%; p=0.01), and reduced risk of being NDO (33.9% vs 46.1%; p=0.002) in the subsequent lactation compared with controls. There were no differences in the incidence of peripartum disease, or the proportion of cows submitted, conceived or pregnant between the Treatment and Control groups in the subsequent lactation (p>0.2). Previously CL-positive (+ve) NDO cows were less likely to produce a female calf that was reared (19.0% vs 29.9%; p=0.005), more likely to be treated as NDO (26.4% vs 18.6%; p=0.02), less likely to conceive by the end of the subsequent lactation's breeding programme (82.2% vs 87.8%; p=0.09), and took longer to conceive (41 vs 33 days from the PSM to conception) than cows that were NDO-CL-negative (-ve) in the previous lactation. There was no interaction between ovarian status and treatment for any of the outcome variables (p>0.05). Cows that were NDO or late-calving in the previous lactation were more likely to be NDO (p<0.005), treated as NDO (p<0.005), and have longer PSM Animal Health Centre, PO Box 21, Morrinsville, New Zealand. Author for correspondence. Email: smcdoug@ahc.co.nz to conception intervals (p<0.005) in the subsequent lactation than cycling herdmates, despite inclusion of factors known to confound reproductive performance in analyses. CONCLUSIONS: Treatment of NDO cows resulted in more female calves reared, earlier calving and a reduced risk of being NDO in the subsequent lactation. Status (i.e. NDO-CL+ve or NDO-CL-ve) affected some reproductive measures in the subsequent lactation, and the effect of treatment in the subsequent lactation differed between the two groups for some measures. Reproductive performance in the subsequent lactation was not improved despite the earlier calving date and longer calving to PSM intervals. Additionally, the previous season's status was still important in the subsequent season's reproductive performance, despite adjusting for known confounders of fertility. CLINICAL RELEVANCE: The economic benefits from treatment of NDO cows are likely limited to effects of an earlier calving date and potential for longer lactation and increased milk yield, increased number of calves derived from artificial insemination and from a reduced number of NDO cows in the subsequent lactation. Effects of improved reproductive performance in the subsequent lactation were not demonstrated and hence should not be included in any economic analysis of therapy of NDO cows.

Risk factors for retained placenta and the effect of retained placenta on the occurrence of postpartum diseases and subsequent reproductive performance in dairy cows

The objectives of this study were to determine the risk factors for retained placenta by evaluating several reproductive factors in individual cows, and to determine the effects of retained placenta on the occurrence of postpartum diseases and subsequent reproductive performance in dairy herds. The health status, cow parity, calving, and breeding dates were recorded from 805 calvings in nine dairy herds from October 2000 to March 2004. We used logistic regression to evaluate the effects of these factors on the incidence of retained placenta. A stepwise procedure, used to obtain the appropriate model with alpha = 0.05, revealed that abnormal partus and gestation length were important risk factors for retained placenta. The occurrence of endometritis and metabolic disorders was greater (p<0.01) in the group with retained placentas than in the control group. The mean intervals from calving to first service and conception were prolonged (p<0.05) by 7 and 18 days, respectively, in the group with retained placentas compared to the control group. These results suggest that abnormal partus and gestation length are strongly correlated with the development of retained placenta, which increases the occurrence of postpartum diseases and subsequently decreases reproductive performance in dairy herds.

Effect of the amount of body condition loss from the dry to near calving periods on the subsequent body condition change, occurrence of postpartum diseases, metabolic parameters and reproductive performance in Holstein dairy cows

We investigated the effect of body condition loss from the dry to near calving periods on the subsequent body condition change, the occurrence of postpartum diseases, the serum metabolic parameters total cholesterol, triglyceride, glucose, and urea nitrogen and the number of days to first breeding after calving in Holstein dairy cows. Body condition scoring (using a 5-point scale with quarter-point divisions) was performed on 67 pregnant Holstein dairy cows. Cows were scored once for body condition during the dry period (prepartum day 35±16), near calving (postpartum day 5±4), and subsequently at months 1 (±day 4), 2 (±day 5), 3 (±day 5), and 4 (±day 4) of lactation. At the same time, blood samples were collected to evaluate serum total cholesterol, triglyceride, glucose and urea nitrogen concentrations. Cows were categorized based on body condition loss from the dry to near calving periods into two groups: the moderate condition loss group (0–0.75 points, n=41), or the marked condition loss group (1.0–1.5 points, n=26). Regular reproductive health examination was conducted by the same investigator once a week. The marked condition loss group lost more body condition ( P<0.01) than the moderate condition loss group consistently until month 1 of lactation. The recovery of body condition in the marked condition loss group was more delayed ( P<0.01) than in the moderate condition loss group from months 1 to 4 of lactation. The occurrence of metritis and metabolic diseases (including abomasal displacement, milk fever, ketosis) was greater ( P<0.01) in the marked condition loss group (62 and 23%) than in the moderate condition loss group (27 and 2%), respectively. The total cholesterol concentration was lower ( P<0.05) in the marked condition loss group (167±5.3 mg/dl) than in the moderate condition loss group (183±5.8 mg/dl) at month 1 of lactation, however, the cholesterol levels at the other periods were not different ( P>0.05) between the two groups. The triglyceride, glucose, and urea nitrogen concentrations were not different ( P>0.05) from the dry period to month 4 of lactation between the two groups. The number of days to first breeding after calving was longer ( P<0.05) in the marked condition loss group (103±7.8 day) than in the moderate condition loss group (87±5.3 day). We conclude that marked body condition loss from the dry to near calving periods results in the increased occurrence of postpartum metabolic and reproductive diseases, decreased serum total cholesterol concentrations at month 1 of lactation and a longer interval to first breeding after calving in Holstein dairy cows, probably due to the more severe energy deficit reflected by unfavorable body condition score change during early lactation.