Elsevier

Theriogenology

Volume 83, Issue 8, May 2015, Pages 1249-1253
Theriogenology

Research article
The prevalence of subclinical endometritis and intrauterine infections in repeat breeder cows

https://doi.org/10.1016/j.theriogenology.2015.01.013Get rights and content

Abstract

The objectives of this study were to assess the prevalence of subclinical endometritis and the presence of common uterine pathogens in repeat breeder cows. A total of 121 cows with three or more consecutive artificial inseminations without conception and no clinical signs of disease were defined as repeat breeder cows and were enrolled in this trial. Intrauterine samples were collected with the cytobrush technique to determine the prevalence of subclinical endometritis and bacteriologic infections. Blood samples were analyzed for concentrations of progesterone and estradiol in plasma to assess ovarian activity. Furthermore, breed, parity, history of calving and postpartum uterine infection, clinical findings of transrectal palpation, and backfat thickness were analyzed as potential factors for the prevalence of subclinical endometritis in repeat breeder cows. The prevalence of subclinical endometritis in repeat breeder cows was 12.7%; but common uterine pathogens, Escherichia coli and Trueperella pyogenes, were found in only one and three cows, respectively. Ovarian activity was determined in 95.0% of all cows. Recorded variables had no effect on the prevalence of subclinical endometritis in repeat breeder cows. In conclusion, subclinical endometritis and uterine infections linked to common pathogens were playing a minor role as a cause for repeat breeder cows in this study. Alternative reasons for failure to conceive in these cows are discussed.

Introduction

Good fertility of dairy cows is the key to economically successful dairy farming. It is generally accepted that uterine disorders in the postpartum period have a negative impact on reproductive performance. In the past decades, the knowledge of the pathophysiology of clinical disorders, e.g., metritis, endometritis, and subclinical endometritis (SE) has increased significantly [1], [2], [3]. Short- and long-term effects of these diseases on fertility have been described [4], [5]. After the postpartum period, repeat breeding is considered one of the most important reproductive disorders in cattle [6]. Repeat breeder cows (RBCs) are defined as cows with regular cycles of 17 to 25 days and with three or more artificial inseminations (AIs) without conception [7], [8]. Recently reported mean prevalence of repeat breeding ranges from 10% to 14% in dairy cows [6], [9]. Although several causes of repeat breeding have been described, e.g., inadequate estrus detection [10], prolonged estrus, delayed LH peak, and late postovulatory rise in plasma progesterone [11], [12], [13], infections [14], and genetic factors [11], the particular reason often remains speculative. With a new diagnostic technique in endometrial cytology, more information can be obtained about these cows. The cytobrush technique has been established as a diagnostic method to detect SE in cows with no signs of clinical endometritis [15], [16]. The proportion of polymorphonuclear neutrophils (PMN) in the total number of endometrial cells is indicative for SE. Different thresholds of PMN for defining SE have been used, ranging from ≥5% [17] to greater than 18% [15]. Some studies have reported the negative impact of SE diagnosed in the postpartum period on fertility [4], whereas others did not confirm these results [17].

In RBCs, one study reported a prevalence of 52.7% SE, and it has been hypothesized that SE is one of the main reasons for cows to become a repeat breeder [18]. Information about intrauterine pathogens in RBCs is rare. It has been assumed that bacteriologic findings are coincidental and not responsible for the failure of cows to conceive [19].

Beside an affected endometrium as a possible reason for failure to conceive, RBCs may also be associated with impaired function of the ovaries [11], [12], [13]. The different aspects of anestrus cows have been described by [20]. Although RBCs are defined as cyclic cows [8], ovarian activity of these cows at the time of insemination is often unknown.

Therefore, the objectives of this study were to describe the prevalence of SE and the presence of common uterine pathogens in the RBC to assess whether RBCs are affected by SE, uterine pathogens or both. Such information would be valuable for discussing prevention and treatment strategies for RBC.

Section snippets

Animals, examinations, and recorded data

This study was approved by the institutional ethics committee and the national authority according to §8 of Law for Animal Experiments, Tierversuchsgesetz-TVG (BMWF-68.205/0137-II/3b/2011).

During the study period from October 2011 to February 2012, RBCs from 40 commercial dairy farms in Austria were enrolled. Herd size ranged from 20 to 218 cows and average 305-day milk production was 5875 to 11,900 kg. Cows were housed in free stalls (n = 38) and tie stalls (n = 2). Rations on all farms were

Descriptive statistics

A total of 121 cows met the inclusion criteria for RBC and were enrolled in this study. Study population consisted of 77.7% dual-purpose Austrian Simmental cows, 9.8% Holstein Friesian, 8.0% Brown Swiss, and 4.5% others. Mean milk production of RBCs that finished a 305-day lactation (n = 60) was 8259 kg (range, 4456–13,495 kg). The distribution of parity was 6.1% heifers, 14.1% primiparous, and 79.8% multiparous cows. Average days from parturition to the first AI were 76 (range, 23–397), and

Discussion

The objectives of this study were to describe the prevalence of SE and intrauterine infection in RBCs. Although several studies reported a prevalence of SE at the end of the postpartum period ranging from 14% to 52% [4], [17], [31], only little information exists about SE later in lactation or in the RBC. Salasel et al. [18] reported a proportion of 53% SE in the RBC. Although study design and the number of cows were similar, these findings did not match the results from our present study. The

Acknowledgments

The authors of the study like to acknowledge the support of the practitioners, the regional Dairy Herd Improvement Service (Landeskontrollverband), and the cooperation with the farm manager. In addition, they would like to acknowledge the financial support of the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva (MINCYT) and the Austrian Bundesministerium für Wissenschaft und Forschung (BMWF) 2010 to 2012.

References (41)

  • R. Kasimanickam et al.

    Endometrial cytology and ultrasonography for the detection of subclinical endometritis in postpartum dairy cows

    Theriogenology

    (2004)
  • R.O. Gilbert et al.

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

    Theriogenology

    (1998)
  • J. Plöntzke et al.

    Subclinical endometritis and its impact on reproductive performance in grazing dairy cattle in Argentina

    Anim Reprod Sci

    (2010)
  • B. Salasel et al.

    Prevalence, risk factors for and impact of subclinical endometritis in repeat breeder dairy cows

    Theriogenology

    (2010)
  • G. Opsomer et al.

    Risk factors for post partum ovarian dysfunction in high producing dairy cows in Belgium: a field study

    Theriogenology

    (2000)
  • U.J. Schröder et al.

    Invited review: methods to determine body fat reserves in the dairy cow with special regard to ultrasonographic measurement of backfat thickness

    J Dairy Sci

    (2006)
  • S. Westermann et al.

    A clinical approach to determine false positive findings of clinical endometritis by vaginoscopy by the use of uterine bacteriology and cytology in dairy cows

    Theriogenology

    (2010)
  • I. Prunner et al.

    Risk factors for uterine diseases on small- and medium-sized dairy farms determined by clinical, bacteriological, and cytological examination

    Theriogenology

    (2014)
  • L.V. Madoz et al.

    The relationship between endometrial cytology during estrous cycle and cutoff points for the diagnosis of subclinical endometritis in grazing dairy cows

    J Dairy Sci

    (2013)
  • Y. Melcher et al.

    Degree of variation and reproducibility of different methods for the diagnosis of subclinical endometritis

    Theriogenology

    (2014)
  • Cited by (50)

    • A reliable method using the cytobrush for diagnosis of subclinical endometritis in dairy cattle during the late lactational period

      2021, Animal Reproduction Science
      Citation Excerpt :

      Subclinical endometritis is a common cause of infertility and subfertility in dairy cows, and occurs during the period of recovery from clinical endometritis, trauma or other non–microbial diseases (Sheldon et al., 2009a, 2009b), and can lead to fibrosis, leukocytosis, atrophy, and depletion of endometrial glands (Sheldon et al., 2006). In contrast to clinical endometritis, common uterine pathogens such as Escherichia coli, Trueperella pyogenes, Fusobacterium necrophorum are rarely detected or are not present when there is SCE (Sens and Heuwieser, 2013; Pothmann et al., 2015; Wang et al., 2018). The lack of bacteria in the uterus of dairy cows with SCE (Madoz et al., 2014) may explain a lack of a correlation between values for cytologic and bacteriologic variables associated with SCE (Baranski et al., 2012).

    • Production of IL-1β, IL-6 and CXCL8 by endometrium of crossbred heifers stimulated with various pathogen-associated molecular patterns

      2021, Animal Reproduction Science
      Citation Excerpt :

      Endometrial transcription of PRR and production of cytokines have been extensively studied in cattle, including how transcription can be affected by stage post-partum (Gabler et al., 2010; Martins et al., 2011), type of post-partum uterine contamination (Borges et al., 2012; Turner et al., 2014), hormonal changes during the estrous cycle (Herath et al., 2006b; Fischer et al., 2010; Saut et al., 2014), and genetic variation between animals (Pinedo et al., 2013). Importantly, infertility in cattle may be associated with changes in endometrial production of cytokines, resulting in insufficient or exacerbated uterine inflammatory responses (Herath et al., 2009; Pothmann et al., 2015). Previous studies have been conducted to characterize the mRNA transcription for PRR in the uterus of Holstein cows during the post-partum periods, when there was not infection or pathological uterine conditions (Herath et al., 2009; Fischer et al., 2010; Martins et al., 2011, 2016), and there was evaluation of the production of pro-inflammatory cytokines by endometrial explants of Holstein heifers at different stages of the estrous cycle in response to various inflammatory stimuli (Borges et al., 2012).

    • Influence of endometritis on milk yield of zero-grazed dairy cows on smallholder farms in Rwanda

      2020, Veterinary and Animal Science
      Citation Excerpt :

      Endometritis is a uterine disease of dairy cows occurring from 21 days in milk (DIM) (Pascottini, Hostens, Sys, Vercauteren & Opsomer, 2017). The disease may be clinical endometritis (CLE) often characterized by vaginal purulent or mucopurulent contents (Eslami, Bolourchi, Seifi, Asadi & Akbari, 2015) or subclinical endometritis (SCLE) characterized by the presence of ≥5% of polymorphonuclear cells in endometrial cytology sample (Pothmann et al., 2015). Endometritis is commonly associated with decreased milk yield (MY) and discarded milk, impaired reproductive performance, increased culling rates, additional costs for drugs, and veterinary services.

    View all citing articles on Scopus
    View full text