Defining postpartum uterine disease and the mechanisms of infection and immunity in the female reproductive tract in cattle

In Vitro Effects of Short-Term and Long-Term Heat Exposures on the Immune Response and Prostaglandin Biosynthesis in Bovine Endometrial Cells

Worldwide heat stress (HS) conditions have a negative impact on dairy cow fertility. However, understanding of the effect of heat stress on endometrial functions is still unclear. The present study aimed to investigate the effects of differential heat exposure conditions on the immune response and prostaglandin biosynthesis of bovine endometrium challenged with bacterial lipopolysaccharide (LPS). Cultures of endometrial cells were grown to confluence at 37 °C (control) and 40.4 °C for 24 h after confluence (short-term heat exposure) and 40.4 °C for 8 days from the beginning of the culture (long-term heat exposure), prior to a challenge by 100 ng/mL LPS for 12 h. LPS altered ALOX12, IL8, IL1B, S100A8, PTGES and AKR1B1 expressions, as well as secretory IL8 and PGF2α. Short-term heat exposure decreased S100A8, IL8 and PGF2α compared with the control temperature, while long-term heat exposure decreased S100A8 and PGF2α. In contrast, HSPA5 expression was not altered by heat exposure or LPS. Indeed, the short-term heat treatment was insufficient for accomplishing the responses of the endometrium to LPS treatment for IL8, S100A8 and PTGES expressions when compared with other temperature conditions. Our findings showed that heat exposure could compromise endometrium immune response and prostaglandin biosynthesis in different ways based on elevated temperature duration, which could reduce subsequent fertility.

Skeletal muscle and adipose tissue reserves and mobilisation in transition Holstein cows: Part 2 association with postpartum health, reproductive performance and milk production

The aim of this study was, for the first time, to simultaneously assess the association of skeletal muscle and subcutaneous fat reserves and their mobilisation, measured by ultrasonography, with the incidence of specific postparturient health, reproduction, and milk production traits. For this purpose, ultrasound measurements of longissimus dorsi thickness (LDT) and backfat thickness (BFT) from 238 multiparous cows from 6 dairy farms were obtained at 6 time points during the transition period (from 21 days pre- to 28 days postpartum). In each case, LDT and BFT measurements at each time point and LDT and BFT mobilisation variables at each study period were assessed simultaneously. Cases of specific clinical postparturient diseases and subclinical ketosis were recorded. An additional disease trait was used, defined as the presence or absence of at least one clinical condition after calving (CD_1-28). The associated disease odds with LDT/BFT variables were assessed with binary logistic regression models. The associated hazard for 1st artificial insemination (AI) and for pregnancy by 150 days-in-milk (PREG_150DIM) was assessed with Cox proportional hazard models. Moreover, binary logistic models were used to assess the associated odds for pregnancy to 1^stAI (PREG_1^stAI). Finally, association with 30d, 100d and 305d milk yield was assessed with linear regression models. Increased muscle depth during transition was negatively associated with odds for metritis and CD_1-28, while associations with odds for subclinical ketosis were inconclusive. Moreover, increased LDT reserves were associated with greater hazard for 1st AI by 150 days-in-milk, but results were inconclusive regarding odds for PREG_1^stAI. Increased LDT mobilisation was associated with increased odds for metritis. Increased BFT reserves were positively associated with odds for metritis, CD_1-28 and subclinical ketosis and with decreased hazard for PREG_150DIM. Increased BFT mobilisation was associated with increased odds for subclinical ketosis and with decreased odds for PREG_1^stAI and decreased hazard for PREG_150DIM. Cows with moderate BFT reserves performed better. Finally, increased BFT mobilisation during -21d to -7d from parturition was associated with less milk by 30d and 100d. On the contrary, increased BFT mobilisation during -7d to 7d was associated with more milk by 305d. Metabolism of muscle and fat tissue during transition period was differently associated with different postparturient health, reproduction and milk production traits. In general, greater muscle mass and moderate fat reserves with limited muscle and fat mobilisation were associated with better performance.

Efficiency of Two Protocols of Resynchronization of Estrus and Ovulation in High-Producing Dairy Cows at Peak Lactation

The reproductive efficiency of the cows was monitored after two resynchronization protocols: Ovsynch (OVS) and Double Ovsynch (DOS). The research initially included 70 HF cows who entered the first synchronization protocol – Presynch. Cows that did not conceive after the first synchronization were divided into two groups and introduced to two resynchronization protocols. In the first group of cows (n=35), the DOS protocol began with the application of GnRH on day 22 after the Presynch TAI (Timed Artificial Insemination), and seven days later pregnancy check-up was done and PGF2α was applied only to non-pregnant cows (n=23), which remained in the study. In the second group of cows, the OVS protocol started on day 32 after Presynch TAI only in non-pregnant animals (n=20). Progesterone (P4) concentration was determined at the time of application of GnRH1, PGF2α and GnRH2 in both groups of cows, and then 30 days after Resynch TAI, ultrasound pregnancy diagnosis was done. A higher percentage of pregnant cows were recorded in the OVS group compared to the DOS group (45% and 35%, respectively). The concentration of P4 in the serum of cows in the DOS group during the first measurement (GnRH1) was significantly higher than the value in cows that did not conceive (p<0.05), while in the third measurement (GnRH2) the average concentration of P4 in conceiving cows was significantly lower (p<0.001) compared to cows that did not coincive. The open days period was significantly longer in pregnant cows that were resynchronized using the DOS protocol compared to cows from the OVS protocol. In conclusion, the OVS protocol of estrus resynchronization in dairy cows proved to be more successful than the DOS protocol. However, considering the advantages the OVS, it is needed to determine which day of the sexual cycle is the best to start resynchronization.

Evaluation of antimicrobial resistance and risk factors for recovery of intrauterine Escherichia coli from cows with metritis on California commercial dairy farms

The goals of this study were to evaluate factors affecting recovery and antimicrobial resistance (AMR) in intrauterine E. coli in post-partum dairy cows with and without metritis from commercial California dairy farms. Using a cross-sectional study design, a total of 307 cows were sampled from 25 farms throughout California, from which a total of 162 intrauterine E. coli isolates were recovered. During farm visits, cows within 21 days post-partum were categorized in one of three clinical presentation groups before enrollment: metritis (MET, n = 86), defined as a cow with watery, red or brown colored, and fetid vaginal discharge; cows with purulent discharge (PUS, n = 106), defined as a non-fetid purulent or mucopurulent vaginal discharge; and control cows, (CTL, n = 115) defined as cows with either no vaginal discharge or a clear, non-purulent mucus vaginal discharge. Cows diagnosed as MET had significantly higher odds for recovery of E. coli compared to cows diagnosed as CTL (OR = 2.16, 95% CI: 1.17–3.96), with no significant difference observed between PUS and CTL, and PUS and MET. An increase in days in milk (DIM) at the time of sampling was significantly associated with a decrease in the odds ratio for E. coli recovery from intrauterine swabs (OR = 0.94, 95% CI: 0.89–0.98). All intrauterine E. coli were resistant to ampicillin (AMP), with an AMR prevalence of 30.2% and 33.9% observed for chlortetracycline and oxytetracycline, respectively. Only 8.6% of isolates were resistant to ceftiofur (CEFT), one of the most common drugs used to treat cows on farms sampled. No significant difference in the prevalence of AMR was observed among clinical groups at the individual cow level. At the farm level, a significantly higher odds for isolating intrauterine E. coli resistant to chlortetracycline (OR: 2.6; 95% CI: 3.7–58.0) or oxytetracycline (OR: 1.9; 95% CI: 1.4–33.8) was observed at farms that used an intrauterine infusion of oxytetracycline as a treatment for metritis when compared to those farms that did not use this practice. Findings from this study indicate the need for further research supporting a broader understanding of farm practices driving AMR in cows with metritis, as well as data to increase the accuracy of breakpoints for AMR classification of intrauterine E. coli from cattle.

Cortisol inhibits lipopolysaccharide-induced inflammatory response in bovine endometrial stromal cells via NF-κB and MAPK signaling pathways

Bovine uterine infection is commonly caused by Escherichia coli (E. coli). Elevated concentrations of plasma cortisol have been reported in postpartum cows. However, the direct role of cortisol in the inflammatory response of bovine endometrial stromal cells (BESCs) remains unclear. Therefore, the aim of the study was to explore the regulatory effect of cortisol on lipopolysaccharide (LPS)-induced inflammatory response in BESCs. Both the primary and immortalized BESCs were used in this study. BESCs were treated with cortisol (5, 15, and 30 ng/mL) in the presence of LPS. The mRNA expression of inflammatory cytokines and chemokines was detected using RT-qPCR. Western blot and immunofluorescence were used to analyze the activation of the NF-κB and MAPK signaling pathways. The results revealed that cortisol downregulated the LPS-induced overexpression of interleukin(IL)-1β, IL-6, IL-8, TNF-α, COX-2, iNOS in BESCs. Moreover, cortisol inhibited LPS-induced phosphorylation levels of IκB, p65, ERK1/2, JNK and p38, and p65 nuclear translocation in BESCs. These results indicated that cortisol inhibited LPS-induced inflammatory response in BESCs, which may be mediated by suppressing the NF-κB and MAPK signaling pathways.

Oxytetracycline Persistence in Uterine Secretion after Intrauterine Administration in Cows with Metritis

Simple Summary

Puerperal metritis in cows involves the acute inflammation of the uterus, which is often treated with antibacterial drugs. Restrictions on the use of antibiotics in veterinary medicine require the very precise selection of an antibiotic based on its pharmacokinetics and on sensitivity tests of pathogenic bacteria. This study aimed to evaluate the changes in oxytetracycline levels in uterine secretion over time after intrauterine administration in cows with metritis in relation to the sensitivity of pathogenic bacterial isolates. The concentrations of oxytetracycline in the uterine secretions were higher than the minimum inhibitory concentrations against pathogenic bacteria, provoking the infection of the uterus. Higher concentrations were measured in milk rather than in plasma. The intrauterine infusion of oxytetracycline for three consecutive days led to the alleviation of the inflammation and the restoration of the estrus cycle in cows. The local intrauterine administration of oxytetracycline requires the monitoring of the withdrawal time of milk to ensure consumer safety.

Abstract

Puerperal metritis in cows is often treated with antibacterial drugs. The prudent use of antibiotics in farm animals requires state-of-the-art knowledge of their pharmacokinetics and data from sensitivity tests of pathogenic bacteria. Changes in oxytetracycline levels in the uterine secretion over time after intrauterine administration in cows with metritis were evaluated in relation to the sensitivity of pathogenic bacterial isolates. Oxytetracycline levels in plasma, milk and uterine secretion were determined via LC–MS/MS analysis. Pathogenic bacteria were isolated and their sensitivity to oxytetracycline was determined. The concentrations of oxytetracycline in the uterine secretion were 433.79 (39.17–1668.76) µg·mL⁻¹ six hours after the third application at a dose of 8 mg/kg and 84.33 (1.58–467.55) µg·mL⁻¹ 96 h after the last treatment. These levels were higher than the minimum inhibitory concentrations—namely, between 4 and 64 µg·mL⁻¹—against pathogenic isolates Trueperella pyogenes, Streptococcus intermedius, Escherichia coli and Bacillus pumilis. Higher concentrations over time were measured in milk rather than in plasma, indicating the need to monitor the withdrawal time for milk. The intrauterine infusion of oxytetracycline for three consecutive days resulted in the successful treatment of metritis in terms alleviating inflammation and restoring the estrus cycle in cows.

Brief Research Report: Expression of PD-1 and CTLA-4 in T Lymphocytes and Their Relationship With the Periparturient Period and the Endometrial Cytology of Dairy Cows During the Postpartum Period

The present study sought to evaluate the expression of PD-1 and CTLA-4 in blood T lymphocytes during the periparturient period and their relationship with uterine health in dairy cows, as determined by endometrial cytology and serum concentrations of β-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFAs), which are indicators of a negative energy balance. The second objective of this study was to investigate whether the expression of PD-1 and CTLA-4 in T lymphocytes is associated with the serum acute phase-protein haptoglobin concentration during the periparturient period. To address these objectives, 26 clinically healthy dairy cows were used. Peripheral blood was collected 14 days prepartum (T-14), at calving (T0), and 30 days postpartum (T30) to measure the expression of PD-1 and CTLA-4 in blood T lymphocytes by flow cytometry. In addition, we collected blood at T0, 10 days after parturition (T10), and T30 to obtain serum and determine the serum concentrations of NEFA, BHB, and Hp. Endometrial cytology was performed at T10, 20 days after parturition (T20), and T30. In the present study, we observed higher expression of CTLA-4 and PD-1 in T lymphocytes at parturition and in the prepartum period, which could indicate a relationship between these immune checkpoints and immunological tolerance during gestation in dairy cattle. In addition, a negative association between the expression of these immune checkpoints prepartum or at parturition and endometrial cytology at T20 and T30 was observed, indicating the negative implications of these immune response regulators in susceptibility to infections. This finding was further corroborated by the relationship between the serum concentration of haptoglobin and the expression of CTLA-4 and PD-1 by T lymphocytes. However, we did not observe a relationship between the indicators of negative energy balance, evaluated by the serum concentrations of BHB and NEFA, and the expression of the immune checkpoint markers studied. Thus, our findings represent an initial step that paves the way for the development of new therapeutic alternatives directed by the host with the objective of increasing the resistance of dairy cattle to infections in this critical period of life.

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

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.

The effect of pre-calving injection of trace mineral supplements on periparturient disease incidence in pasture based dairy cows

Trace minerals, have a role in immune function and a trace mineral supplement (TMS) can improve animal health in dairy herds. This prospective randomised clinical study assessed whether subcutaneous injection of 5.5 mL of TMS (40 mg zinc, 10 mg manganese, 5 mg selenium, 15 mg copper per mL), 14-28 days before planned start of calving (PSC) reduced clinical mastitis (CM), subclinical mastitis (SCM) and purulent vaginal discharge (PVD). From four farms, half of 1700 cows stratified on somatic cell count, age and breed were randomly allocated to treatment or no treatment. Occurrence of CM from - 7 to PSC + 100 days, SCM at PSC + 60 days and PVD at PSC + 24 days was analysed using survival analysis and Bayesian generalised mixed multivariable models. From -7 to PSC +30 days, TMS reduced the adjusted hazard ratio (HR) for CM at quarter and cow level (P < 0.001), with no evidence for an effect beyond 30 days. The adjusted OR (and 95% highest density interval, HDI) for the effect of TMS on CM from -7 to PSC +30 days was 0.40 (95% HDI, 0.26-0.63) at quarter level, 0.51 (95% HDI, 0.38-0.69) at cow level and for SCM, 0.72 (95% HDI, 0.54-0.95). The difference in CM incidence from TMS at the cow level was -2.0% (95% HDI, -3.4 to -1.1%) and -1.2% (95% HDI, -3.2 to - 0.6%) at quarter level. No clear effect was identified of TMS on cumulative incidence of PVD.

In-Depth Analysis of an Obligate Anaerobe Paraclostridium bifermentans Isolated from Uterus of Bubalus bubalis

Simple Summary

Non-specific uterine infections in bovine (uterine line inflammation) are a significant issue for the dairy industry. These infections are responsible for significant financial losses all over the world. Paraclostridium bifermentans is an obligate anaerobe, gram-positive rod-shaped bacteria belonging to the Clostridia class and the Peptostreptococcaceae family produces endospores. This bacterium has the ability to infiltrate bovine uterine endometrial epithelial cells and cause infection in the endometrium epithelial cells. Our study found that an examination of a buffalo uterus with yellowish purulent discharge reported the presence of pathogenic bacteria Paraclostridium bifermentans, where its genomic characterization, substrate utilization, and antibiotic susceptibility potentiality was studied. This discovery indicates the presence of virulence genes as well as pathogenic features. This is the first report of P. bifermentans from the bovine uterus environment.

Abstract

Chronic non-specific contamination of the reproductive tract in animals is a major issue during early postpartum, natural coitus, or artificial insemination. Uterine infection is one of the major concerns reducing fertility, production loss, and early culling of the animals. Therefore, the aim of this study was to identify any novel bacterium if present in the uterine environment of Bubalus bubalis causing infections. A strictly anaerobic bacterial strain designated as Paraclostridium bifermentans GBRC was isolated and characterized. Bacterium was found to be Gram positive moderate rod with motility. The optimum growth was observed at 40 ± 2 °C. The pathogenic characteristics of the GBRC strain, such as hemolysis, gelatin hydrolysis, and the production of volatile sulfur compounds, were similar to those seen in the epithelial layer invading pathogenic strains. Assembled genome size was 3.6 MB, with 78 contigs, and a G + C content of 28.10%. Furthermore, the whole genome sequence analysis confirmed the presence of genes encoding virulence factors and provided genomic insights on adaptation of the strain in the uterine environment. Based on the phenotypic and genetic differences with phylogenetic relatives, strain GBRC is proposed to represent a first reported species of the genus Paraclostridium with potential pathogenic character, from the buffalo uterine environment. This study analysis of the GBRC strain serves as a key reference point for the investigation of potential pathogenic strains that may cause endometritis and metritis in bovine.

Responses of selected biomarkers, female reproductive hormones and tissue changes in non-pregnant does challenged with Mannheimia haemolytica serotype A2 and its outer membrane protein (OMP) immunogen

BACKGROUND

Mannheimia haemolytica causative agent of pneumonic mannheimiosis, a common respiratory disease of goat and sheep, which cause huge economic losses to farmers worldwide. Pneumonic mannheimiosis caused by M. haemolytica serotype A2 has been reported among small ruminants in Malaysia. The lipopolysaccharide (LPS) and outer membrane protein (OMP) are major virulence determinants for M. haemolytica serotype A2. Although pneumonic mannheimiosis is known to cause poor reproductive performance in small ruminants under field conditions, there is a dearth of published information on the specific effects of M. haemolytica serotype A2 infection on the female reproductive physiology. In this experiment, we explored the impact of M. haemolytica serotype A2 and its OMP immunogen on selected pro-inflammatory cytokines, acute phase proteins, female reproductive hormones, and cellular changes in visceral and female reproductive organs of non-pregnant does.

METHODOLOGY

Twelve healthy, non-pregnant, Boer crossbreds does were divided equally into three groups (n = 4); Group 1 served as the negative control and was challenged with 2 ml of sterile PBS intranasally. Group 2 served as the positive control and was challenged with 2 ml of 10⁹ colonies forming unit (CFU) of M. haemolytica serotype A2 suspension intranasally. Group 3 was challenged with 2 ml of OMP extracted from 10⁹ CFU of M. haemolytica A2 intramuscularly. The experimental does were monitored for clinical signs and responses periodically. Blood samples were collected at 0, 1, 2, 4, 6, 12 and 24 h and 3, 7, 21, 35 and 56 days post treatment for serological analyses. All does were euthanised using the halal slaughter method on day 60 post challenge/treatment. Tissues from the uterus, liver, lung and associated bronchial lymph nodes were collected and fixed in 10% formalin for 14 days for histopathological study.

RESULTS

Compared to the control group, the challenged/treated groups showed significant (p < 0.05) increase in the rectal temperature, respiratory rate, heart rate, and rumen motility. Serum analyses revealed that the concentrations of progesterone and estrogen hormones were significantly (p < 0.05) decreased in groups 2 & 3. In contrast, the concentrations of pro-inflammatory cytokines (IL-1β and IL-6) and acute phase proteins (Hp and SAA) were significantly increased (p < 0.05) in the challenged/treated groups compared to the control group. Histopathological lesion scoring revealed mild to moderate cellular changes characterised by congestion, haemorrhage, degeneration, leucocytic cellular infiltration, and cellular necrosis in the tissues of does from the OMP treatment and bacterial challenge groups compared to the control group.

CONCLUSION

The findings from this study suggests that M. haemolytica serotype A2 and its OMP immunogen induced mild to moderate inflammatory and degenerative changes which may potentially interfere with fertilization through hormonal imbalances and cause temporary loss of fertility in infected does.

An in vitro comparison of antimicrobial efficacy and cytotoxicity between povidone-iodine and chlorhexidine for treating clinical endometritis in dairy cows

This study aimed to assess the in vitro antimicrobial effects of chlorhexidine (CHX) and povidone-iodine (PI) on clinical isolates of Escherichia coli (E. coli) and Trueperella pyogenes (T. pyogenes) from the vaginal discharge of dairy cows, as well as to compare the cytotoxicity effects of CHX and PI on bovine endometrial epithelial cells (BEnEpC). In Experiment 1, 12 E. coli and 10 T. pyogenes were isolated from the vaginal discharge of cows with a uterine infection. The MIC and MBC against CHX and PI were analyzed in vitro. In Experiment 2, the cytotoxicity effects of CHX and PI on BEnEpC were analyzed using a Viability/Cytotoxicity Kit, wound scratch healing assay, and the expression of pro-inflammatory cytokine genes (IL-6, IL-8, and TNF-α). In Experiment 1, the MIC and MBC values of CHX against E. coli were 0.0002% and 0.0002 to 0.00025%, respectively. The MIC and MBC values of PI were 1.25 to 2.5% and 1.25 to 5%, respectively. For T. pyogenes, the MIC and MBC values of CHX were 0.00002%. The MIC and MBC values of PI were 1.25%. In Experiment 2, the cell viability significantly decreased, and wound closures were significantly inhibited after treatment with ≥ 0.002% CHX and ≥ 0.025% PI. The expression of IL-6, IL-8, and TNF-α significantly increased after treatment with PI. Only IL-6 showed a significant increase after cells were treated with 0.00002% and 0.0002% CHX. The results suggested that both CHX and PI had high antibacterial effects. However, veterinarians and farmers should be aware of their cytotoxicity, which decrease viability of endometrial epithelial cells and inhibit wound healing in vitro.

Bacterial Communities of the Uterus and Rumen During Heifer Development With Protein Supplementation

Bacterial communities play major roles in rumen and uterine function toward optimal animal performance and may be affected by changes occurring during heifer development such as nutritional supplementation for optimal growth and the attainment of puberty. The effect of different levels of protein supplementation on ruminal and uterine bacterial communities following weaning was examined through first breeding of heifers. Angus heifers (n = 39) were blocked by initial body weight (BW) and randomly assigned to one of three 163-day (d) crude protein (CP) supplementation diets including control (10% CP, n = 14), 20% CP (n = 11), or 40% CP (n = 14) treatment groups. Growth and development were monitored by body weight, with blood progesterone concentration determined every 14 d to determine pubertal status. Uterine flush and rumen fluid were collected on d 56, 112, and 163 relative to the start of supplementation. Bacterial DNA was extracted from fluid samples, the V1–V3 hypervariable region of the 16S rRNA gene was amplified, and amplicons were sequenced then processed in R 4.1. Statistical analyses were performed in SAS 9.4 with a GLIMMIX procedure utilizing fixed effects of protein, month, pubertal status, and interactions, with random effects including BW, interaction of BW and protein, and heifer within the interaction, and repeated measures of day. In the uterus, pubertal status and day of supplementation affected the observed amplicon sequence variants (ASVs) and led to clustering of samples in a principal coordinate analysis (PCoA; P &lt; 0.05), but no effect of protein supplementation was observed. Ruminal samples clustered in PCoA (P = 0.001), and observed ASVs were impacted over time (P &lt; 0.0001), but no effect of protein supplementation was detected. In contrast, protein supplementation, pubertal status, and day of supplementation affected the abundance of multiple phyla and genera in the uterus and rumen (P &lt; 0.05). Temporal and pubertal status effects on the heifer’s uterine bacterial communities potentially indicate a maturing uterine microbiome. Protein supplementation did not impact microbial diversity measures but did affect the abundance of individual bacterial phyla and genera that may provide future opportunities to manipulate bacterial community composition and maximize productivity.

Identification and Validation of Autophagy-Related Genes in Primary Ovarian Insufficiency by Gene Expression Profile and Bioinformatic Analysis

Background

To investigate the relationship between primary ovarian insufficiency and autophagy, we detected and got the expression profile of human granulosa cell line SVOG, which was with or without LPS induced. The expression profile was analyzed with the focus on the autophagy genes, among which hub genes were identified.

Results

Totally, 6 genes were selected as candidate hub genes which might correlate with the process of primary ovarian insufficiency. The expression of hub genes was then validated by quantitative real-time PCR and two of them had significant expression change. Bioinformatics analysis was performed to observe the features of hub genes, including hub gene-RBP/TF/miRNA/drug network construction, functional analysis, and protein-protein interaction network. Pearson's correlation analysis was also performed to identify the correlation between hub genes and autophagy genes, among which there were four autophagy genes significantly correlated with hub genes, including ATG4B, ATG3, ATG13, and ULK1.

Conclusion

The results indicated that autophagy might play an essential role in the process and underlying molecular mechanism of primary ovarian insufficiency, which was revealed for the first time and may help to provide a molecular foundation for the development of diagnostic and therapeutic approaches for primary ovarian insufficiency.

Understanding microbial networks of farm animals through genomics, metagenomics and other meta-omic approaches for livestock wellness and sustainability – A Review

The association of microorganisms with livestock as endosymbionts, opportunists, and pathogens has been a matter of debate for a long time. Several livestock-associated bacterial and other microbial species have been identified and characterized through traditional culture-dependent genomic approaches. However, it is imperative to understand the comprehensive microbial network of domestic animals for their wellness, disease management, and disease transmission control. Since it is strenuous to provide a niche replica to any microorganisms while culturing them, thus a substantial number of microbial communities remain obscure. Metagenomics has laid out a powerful lens for gaining insight into the hidden microbial diversity by allowing the direct sequencing of the DNA isolated from any livestock sample like the gastrointestinal tract, udder, or genital system. Through metatranscriptomics and metabolomics, understanding gene expression profiles of the microorganisms and their molecular phenotype has become unchallenging. With large data sets emerging out of the genomic, metagenomic, and other meta-omics methods, several computational tools have also been developed for curation, assembly, gene prediction, and taxonomic profiling of the microorganisms. This review provides a detailed account of the beneficial and pathogenic organisms that dwell within or on farm animals. Besides, it highlights the role of meta-omics and computational tools in a comprehensive analysis of livestock-associated microorganisms.

Investigation of the Role of Pituitary Adenylate Cyclase-Activating Peptide (PACAP) and Its Type 1 (PAC1) Receptor in Uterine Contractility during Endometritis in Pigs

Uterine inflammation is a common pathology in animals, leading to disturbances in reproductive processes and reduced production profitability. Pituitary adenylate cyclase-activating peptide (PACAP) effects at the uterine level during inflammation are not known. In the current study, we analyzed the relative PACAP type 1 receptor (PAC1R) mRNA transcript and protein abundances in the myometrium (MYO), as well s PACAP and PAC1R involvement in the contractile function of inflamed pig uterus. To that end, E. coli suspension (E. coli group) or saline (SAL group) was injected into the uterine horns or laparotomy was performed (CON group). Eight days after the bacteria injections, severe acute endometritis and a reduced relative abundance of PAC1R protein in the MYO were observed. Compared to the period before PACAP in vitro administration, PACAP (10^-7 M) in the CON and SAL groups decreased in amplitude in the MYO and endometrium (ENDO)/MYO, whereas in the E. coli group, increased amplitude in the MYO and reduced amplitude in the ENDO/MYO were observed. In the E. coli group, PACAP enhanced the amplitude in the MYO (10^-7 M) and decreased the amplitude in the ENDO/MYO (10^-8 M) compared with other groups. PACAP (10^-7 M) increased the frequency of both kinds of strips in the CON and SAL groups compared with the pretreatment period. PACAP (both doses) did not significantly change the frequency in the E. coli group, whereas in response to PACAP (10^-7 M), the frequency was reduced compared to other groups. In the MYO, PAC1R antagonist decreased the amplitude reduction (CON and SAL groups) and reversed a rise in PACAP (10^-7 M)-evoked amplitude (E. coli group). PAC1R blocking reversed (MYO) and abolished (ENDO/MYO) the stimulatory effect of PACAP (10^-7 M) on the frequency (CON and SAL groups). PAC1R antagonist and PACAP (10^-7 M) evoked the appearance of frequency depression in both kinds of strips (E. coli group). In summary, in pigs, severe acute endometritis reduces the relative abundance of PAC1R protein in the MYO, and PAC1R mediates the influence of PACAP on inflamed uterus contractility.

Effect of calving to timed artificial insemination interval on fertility of beef cows

The objectives of this study were to determine the effect of calving to timed artificial insemination (C-TAI) interval on fertility of Bos taurus and Bos indicus cows, and to determine the best C-TAI interval to include postpartum cows in TAI programs in each genotype (B. taurus and B. indicus). In experiment 1, a retrospective study was performed, with data from 2709 TAI in Bos taurus and Bos indicus cows with different C-TAI intervals. There was a positive linear effect of C-TAI interval on the pregnancy probability (P < 0.0001). However, there was no effect or interaction with the genotype. When C-TAI intervals were grouped in classes, pregnancy rate differed in groups (P < 0,05). Receiver operating characteristic (ROC) analysis was performed and it was observed that 52 days would be the better C-TAI interval to maximize fertility in beef cows. According to previous result, we further stratified into two C-TAI interval groups (≤ 52 days or > 52 days). Cows with C-TAI longer than 52 days (C-TAI>52) had greater pregnancy rate (56%) than cows with short C-TAI (46%; P < 0.01). In experiment 2, 18 postpartum beef cows were subjected to TAI protocol at different C-TAI intervals (n = 6 cows per group): 40, 60 or 80 days postpartum. Cows with 60 days of C-TAI had a greater preovulatory follicle diameter than cows with 80 days postpartum (P < 0.05). The C-TAI interval did not affect (P > 0.05) the ovulation rate nor the proportion of endometrial polymorphonuclear leukocytes. We conclude that C-TAI interval affects pregnancy rate in both Bos taurus and Bos indicus. We recommend a C-TAI interval longer than 52 days to increase fertility of beef cows included in TAI programs.

Effect of retained placenta and clinical mastitis on reproduction parameters, immune response, and steroidogenic receptors gene expression in postpartum crossbred dairy cows

The purpose of this study was to evaluate the effect of retained placenta (RP) and clinical mastitis (CM) on the reproductive efficiency of crossbred dairy cows during the postpartum period and the effect in some innate immune system indicators. For this, two experiments were carried out. In the first, a total of 232 cows were evaluated and divided as: healthy control (n = 184), RP (n = 22), and CM (n = 26) groups. The RP and CM was evaluated until 30 days postpartum (DPP) and reproductive rates were measured. In experiment 2, cows were divided in control (n = 10), RP (n = 10), and CM (n = 30) groups. Between 40 and 50 DPP, clinical, gynecological examination and endometrial cytobrush were performed to evaluate subclinical endometritis (SE) and gene expression of interleukins 1β (IL-1β) and 6 (IL-6), chemokine ligand 5 (CCL5), estrogen α (ESR1), and progesterone (PGR) receptors by qRT-PCR analysis. In experiment 1, the conception rate at 1st artificial insemination (AI) was lower in RP and CM groups and pregnancy rate at 150 days decreased in CM group. Calving-to-1st AI interval and days open were shorter in healthy cows. In experiment 2, the occurrence of SE was 26.7% and higher in RP and CM groups. The expression of IL-1β increased in RP and CM groups, while IL-6 was less expressed in RP group. The CCL5, ESR1, and PGR were similar between groups. In conclusion, cows with RP and CM had their reproductive efficiency negatively affected and had they initial pro-inflammatory response improved by the increase of IL-β.

Prevalence and risk factors associated with repeat breeding of beef cattle in Sleman Regency, Indonesia

Background and Aim:

Various management practices may cause the occurrence of reproductive failure indicated by repeat breeding in beef cattle. This study aimed to estimate the prevalence and the risk factors of repeat breeding in beef cattle in Sleman Regency, Indonesia.

Materials and Methods:

Observational and cross-sectional studies were used to determine the prevalence and the risk factors of repeat breeding. Sampling was conducted using a multistage cluster design. The sample size was determined using a sampling formula (n=4 PQ/L2). Questionnaire and interview data were evaluated descriptively. Chi-square analysis and odds ratio (OR) test were conducted to determine the association and association strength with a confidence level of 95%. Univariate, bivariate, and multivariate analysis through multivariate logistic regression test was done using Statistical Package for the Social Sciences, version 21.0 software.

Results:

The results indicated that the prevalence of repeat breeding in beef cattle in the Sleman Regency was 30.4%. Multivariate analysis indicated that risk factors that significantly affected the repeat breeding were breeding experience (p=0.000; OR=3.378), knowledge of estrus cycle (p=0.000; OR=5.263), feed type (p=0.001; OR=6.061), feeding frequency (p=0.003; OR=2.77), shed hygiene (p=0.33; OR=2,381), and drainage system (p=0.000; OR=4,484).

Conclusion:

Various husbandry management significantly influence the incidence of repeat breeding in beef cattle in Sleman Regency with the type of feed, which was the highest risk factor. Hay should not be used as the main feed source since it might increase the incidence of repeat breeding. However, the other environmental factors such as season and presence of infection or parasite also need to be investigated further.

The endometrial transcriptomic response to pregnancy is altered in cows after uterine infection

Pregnancy induces changes in the transcriptome of the bovine endometrium from 15 days after insemination. However, pregnancy is less likely to occur if cows had a postpartum bacterial infection of the uterus, even after the resolution of disease. We hypothesized that uterine bacterial infection alters the endometrial transcriptomic signature of pregnancy after the resolution of disease. To examine the endometrial transcriptomic signature of pregnancy, cows were inseminated 130 days after intrauterine infusion of pathogenic Escherichia coli and Trueperella pyogenes, subsequently endometrium was collected 16 days after insemination for RNA sequencing. We found 171 pregnancy regulated genes in cows 146 days after bacterial infection. When comparing our findings with previous studies that described the endometrial transcriptomic signature of pregnancy in healthy cows, 24 genes were consistently differentially expressed in pregnancy, including MX1, MX2 and STAT1. However, 12 pregnancy regulated genes were found only in the endometrium of healthy cows, including ISG15 and TRANK1. Furthermore, 28 pregnancy regulated genes were found only in the endometrium of cows following bacterial infection and these were associated with altered iNOS, TLR, and IL-7 signaling pathways. Although 94 predicted upstream regulators were conserved amongst the studies, 14 were found only in the endometrium of pregnant healthy cows, and 5 were found only in cows following bacterial infection, including AIRE, NFKBIA, and DUSP1. In conclusion, there were both consistent and discordant features of the endometrial transcriptomic signature of pregnancy 146 days after intrauterine bacterial infusion. These findings imply that there is an essential transcriptomic signature of pregnancy, but that infection induces long-term changes in the endometrium that affect the transcriptomic response to pregnancy.

In vitro evaluation of probiotic properties of lactic acid bacteria isolated from the vagina of yak (Bos grunniens)

Bovine endometritis is an inflammatory disease of the uterus that occurs after parturition and can result in the destruction of uterine microecology, disruption of hormone secretion, and even infertility. Problems such as antibiotic residues, pathogen resistance, and microbiota dysbiosis caused by conventional antibiotic therapy cannot be ignored. According to the microecological balance theory, probiotics have the potential to prevent or cure endometritis in cattle. Probiotics can positively influence host physiology by regulating microecological imbalance, modulating immunity, and antagonizing pathogens. Since some probiotics contribute to host health only in their specific natural niches, lactic acid bacteria (LAB) from the vagina may have better potential to fight against vaginal and uterine infection. The yak (Bos grunniens) is an ancient and primitive livestock animal that is adapted to high altitude and harsh environments (cold, nutritional deficiencies, and hypoxia). However, to our knowledge, there have been no studies on yak vaginal LAB. Therefore, the purpose of this study was to isolate vaginal LAB from yak, evaluate and compare the probiotic potential and safety of the isolates, and help establish the probiotics library that can be used in the prevention and/or treatment of endometritis. Twenty-five vaginal swabs were collected from healthy yak and cultured in deMan, Rogosa, and Sharpe (MRS) broth. Tentative LAB strains were preliminarily determined through calcium dissolving zone and morphological identification, and the strains were then identified using 16S rRNA gene sequencing. The probiotics of the isolates were detected using cell aggregation, hydrophobicity, resistance to acid and bile salt, adhesion, and antibacterial activities. Additionally, antimicrobial susceptibility, hemolytic activity, and detection of potential virulence factors were determined in order to confirm the safety of these strains. Five isolates were identified: Leuconostoc mesenteroides, Lactobacillus plantarum, Enterococcus hirae, Lacticaseibacillus camelliae, and Lactobacillus mucosae. All isolates had certain growth resistance, aggregation ability, effective antimicrobial potency against Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium, were sensitive to most antibiotics, and could effectively adhere to bovine endometrial epithelial cells (BEECs). None of the isolates showed hemolytic activity or harbored virulence factors. Our results indicated that the five isolates have considerable potential as probiotics that can be used to prevent and/or treat bovine endometritis. We speculate that a mixture of YD6, YD9, and YD25 may yield better results, although this would require extensive experiments to verify.

Latest update on predictive indicators, risk factors, and 'Omic' technologies research of retained placenta in dairy cattle- review article

Retained placenta is a pathological condition defined as failure to expel fetal membranes within 12 -24h after parturition. It instigates important financial losses to the dairy industry causing considerable economic loss. It is a multifactorial disorder. Although different hypotheses have been proposed, contradictory results and no single factor explains the development of the disease. This indicates that there are overall significant gaps in our knowledge about the various factors affecting the etiopathology and pathobiology of the retained placenta. Thus, it will be of great interest to investigate the potential contributing factors that influence the occurrence of RP which provide us with the mechanisms to avoid the occurrence of the disease. In addition, different predictive indicators of RP should be part of our research, thus providing the essential procedures applied to deal with the disease and the development of novel therapeutic and prophylactic strategies in its management. Furthermore, lately, the molecular role takes attention to understanding its effect in the occurrence of the disease. Such information might help dairy scientists in the future to design better management and preventive practices for RP in dairy cows.

Effect of metritis on in-vitro uterine contractility in cows during the puerperium

Aim of this study was to determine the effect of metritis on in-vitro uterine contractility. Uteri obtained from 16 euthanized Holstein-Friesian cows were divided into two groups depending on whether metritis was absent (M-, n = 6) or present (M+, n = 10). Four longitudinal and four circular myometrial strips of all uteri were incubated in an organ bath. Spontaneous contractility was recorded in five consecutive 30-minute periods (T1-T5). This was followed by stimulation of one longitudinal and one circular strip with increasing concentrations of oxytocin, prostaglandinF_2α (PGF_2α), and calcium chloride (each during four 30-minute periods [T6-T9]). Strips in group M+ had higher minimum amplitude (minA) values at T1 and higher minA, mean amplitude (meanA), and area under the curve (AUC) values at T2 than strips in group M- (P ≤ 0.05). In the M+ group, the maximum amplitude (maxA), meanA, and AUC values of circular strips were higher than those of longitudinal strips during spontaneous contractility (T1, T4, and T5; P ≤ 0.05). The minA, meanA, and AUC values for strips in group M+ were higher than those in group M- when exposed to the highest concentration of PGF_2α (P ≤ 0.05). During stimulation with PGF_2α (T9), longitudinal strips had higher maxA values than the circular strips in group M+ (P ≤ 0.05). Spontaneous and stimulated contractility were temporarily increased in uteri with metritis compared to healthy uteri. Both myometrial layers, especially in uteri with metritis, reacted differently during spontaneous contractility and to stimulation with PGF_2α.

The Antioxidant Role of Selenium via GPx1 and GPx4 in LPS-Induced Oxidative Stress in Bovine Endometrial Cells

This study investigated the antioxidant role of selenium (Se) in the form of selenomethionine (SLM) in LPS-induced oxidative stress via the glutathione peroxidase (GPx) enzymes and the Nrf2/HO-1 transcription factor. The impact of serum supplementation in culture media on GPxs was also studied. The bovine uterus is constantly exposed to exogenous pathogens postpartum, and the endometrium is the first contact against bacteria invasion. Endometritis is an inflammation of the endometrium and is brought about by bacterial lipopolysaccharide capable of inducing oxidative stress. The BEND cells were supplemented at the point of seeding with the following SLM concentrations 0, 100, 500, and 1000 nM for 48 h. BEND cells, cultured with or without SLM (100 nM), were initially incubated for 48 h, and then, we serum starved the SLM group for 24, 48, and 72 h. Similarly, an assay involving serum volume (0, 2, 5, and 10%) supplementation in culture media (v/v) with or without SLM (100 nM) was performed for 48 h. The BEND cells were also seeded into four experimental groups and cultured for an initial 48 h as follows: control, LPS (20 μg/mL), SLM (100 nM), and SLM + LPS groups followed by 6-h LPS treatment. The role of SLM in modulating the expressions of GPx1 and GPx4 and the Nrf2 transcription factor-related genes was assessed using qRT-PCR and Western blot techniques. The results showed serum starvation in the presence of SLM supplementation decreased the expression of GPx1 enzyme but increased GPx4 compared to the control. The addition of SLM to cell culture media in an FBS limiting condition improved the expressions of both GPx1 and GPx4. SLM supplementation promoted GPx enzymes' expressions in a serum-free media (0%) and at 2% FBS in media. However, it did not improve their expressions at 10% FBS in media than the untreated groups. Together, our data show the protective role of Se by regulating the expressions of GPx1 and GPx4 enzymes in BEND cells. It also shows that SLM promoted the expression of Nrf2 transcription factor-related genes at both the mRNA and protein levels in BEND cells during LPS stimulation.

How to Predict Parturition in Cattle? A Literature Review of Automatic Devices and Technologies for Remote Monitoring and Calving Prediction

Cattle farming is facing an increase in number of animals that farmers must care for, together with decreasing time for observation of the single animal. Remote monitoring systems are needed in order to optimize workload and animal welfare. Where the presence of personnel is constant, for example in dairy farms with great number of lactating cows or with three milking/day, calving monitoring systems which send alerts during the prodromal stage of labor (stage I) could be beneficial. On the contrary, where the presence of farm personnel is not guaranteed, for example in smaller farms, systems which alert at the beginning of labor (stage II) could be preferred. In this case, time spent observing periparturient animals is reduced. The reliability of each calving alarm should also be considered: automatic sensors for body temperature and activity are characterized by a time interval of 6-12 h between the alarm and calving. Promising results have been shown by devices which could be placed within the vaginal canal, thus identifying the beginning of fetal expulsion and optimizing the timing of calving assistance. However, some cases of non-optimal local tolerability and cow welfare issues are reported. Future research should be aimed to improve Sensitivity (Se), Specificity (Sp) and Positive Predictive Value (PPV) of calving alert devices in order to decrease the number of false positive alarms and focusing on easy-to-apply, re-usable and well tolerated products.

Relationship between Escherichia coli virulence factors, notably kpsMTII, and symptoms of clinical metritis and endometritis in dairy cows

Although Escherichia coli is a commensal bacterium of the bovine vaginal microbiota, it is an important pathogenic bacterium that causes diseases of the reproductive tract and sub-fertility. Recent studies have focused on virulence factors (VFs) of intrauterine E. coli; however, actual endometrial VFs have not been clearly identified. The purpose of this study was to identify the VFs of E. coli associated with clinical metritis and endometritis. Thirty-two strains of E. coli and four mixed Trueperella pyogenes (TP) strains were detected in the uterus of 19 Holstein dairy cows with obvious clinical signs (between 8 and 66 days postpartum). The presence of six E. coli VFs (fimH, fyuA, kpsMTII, hra1, csgA, and astA) was examined by PCR, and clinical signs and reproductive performance (mixed TP, the percentage of polymorphonuclear neutrophils [PMN%], days to uterine involution, etc.) were evaluated. Four VFs (fimH, hra1, csgA, and astA) were detected in all E. coli strains, whereas fyuA and kpsMTII were detected in 94% and 50% of strains, respectively. Cows with E. coli strains harboring kpsMTII exhibited significantly severe clinical scores (vaginal discharge score, PMN%, uterine involution), suggesting that kpsMTII is a key VF for progression of clinical metritis and endometritis. In the present study, we clearly identified six VFs associated with clinical metritis and endometritis. In addition, E. coli strains with kpsMTII probably play a crucial role in the progression of clinical metritis and endometritis.

Quantitative and functional dynamics of circulating and endometrial polymorphonuclear leukocytes in healthy peripartum dairy cows

The aim of the present study was to assess the counts, viability, and functionality of circulating and endometrial polymorphonuclear leukocytes (PMN) isolated from fourteen clinically and metabolically healthy multiparous dairy cows in the peripartum period. For this, blood samples were collected at -5, +9, +21 and + 37 days (d) relative to calving. Cytology samples were collected from the vagina, cervix, and uterus at +9, +21 and + 37 d, using the cytobrush technique. Additional vaginal samples were collected at -5 d. Cytology smears were prepared and the PMN-to-all nucleated cell proportions (PMN%) were calculated. The endometrial cytobrush samples were also used for flow cytometric assessment of endometrial PMN (ePMN) viability and functionality. Functionality tests for circulating PMN (cPMN) included phagocytosis (PC), oxidative burst, and intracellular proteolytic degradation. For ePMN, we evaluated PC only. The effect of day relative to calving on PMN viability and functionality were fitted in linear regression models, accounting for repeated measures. The endometrial PMN% were higher at +9 d (23.5 ± 0.4%; least-squares means ± standard error) and +21 d (8.5 ± 0.3%) than at +37 d (1.4 ± 0.3%). No changes in PMN% were found on either vaginal or cervical cytology along the peripartum period. The cPMN counts were higher pre- (6.2 ± 0.4 x 10⁶/mL) than postpartum (4.9 ± 0.4 x 10⁶/mL). Upon viability analysis, only the percentage of viable cPMN tended to be lower at -5 d (90.1 ± 1.5%) than at +37 d (94.1 ± 1.4%), and no other changes in the percentage of apoptotic and necrotic cPMN, nor in their functionality were found during the peripartum period. Analysis of ePMN viability showed that the percentage of viable ePMN did not change over time. In marked contrast, the percentage of apoptotic ePMN was higher at +9 d (37.8 ± 5.1%) than at +21 d (20.9 ± 5.1%) and +37 d (11.9 ± 5.3%), while the percentage of necrotic ePMN was lower at +9 d (27.0 ± 6.3%) than at +37 d (54.9 ± 6.6%). The percentage of ePMN PC was higher at +9 d (27.5 ± 3.4%) than at +37 d (13.3 ± 4.9%). In conclusion, during the peripartum period ePMN in the healthy postpartum uterus are highly dynamic in terms of counts, viability, and functionality compared to their circulating counterparts.

Alteration in Activity Patterns of Cows as a Result of Pain Due to Health Conditions

Simple Summary

There are several conditions and diseases considered painful to cattle. One reason for the inconsistency in pain recognition and thus pain relief in cattle is the inadequate ability to identify and assess pain. In fact, both increased and/or reduced daily lying time can be indicative of pain in cattle. This review helps to properly interpret pain in cows through behavioural activity patterns and explores whether pain relief is capable to restore their normal activity.

Abstract

The main conditions and diseases considered painful in dairy cows are mastitis, lameness, calving (including dystocia and caesarean section) and metritis. The cattle literature reports that deviation from normal daily activity patterns (both increased and/or reduced daily lying time) can be indicative of painful conditions and diseases in cows. This narrative review discusses on how pain due to several health conditions in dairy cows modifies its activity pattern and explores if non-steroidal anti-inflammatory drugs (NSAIDs) are capable of restoring it. Divergent outcomes may differ depending upon the painful cause, the severity and the moment, and consequently its interpretation should be properly explained. For instance, cows with clinical mastitis reduced their time lying and increased the number of lying bouts and stepping due to pain caused by the swollen udder when cows are lying. However, lame cows show longer lying times, with a lower number of lying bouts and longer and more variable lying bouts duration, as compared to non-lame cows. When the relationship between painful disorders and daily activity patterns is studied, factors such as parity, bedding type and severity of disease are important factors to take into consideration. The potential benefits of the NSAIDs treatment in painful health disorders depend upon the type of drug administered, its dosage and administration mode, and the time of administration relative to the painful health disorder. This narrative review can be used as a tool to properly interpret and grade pain in cows through behavioural activity patterns and proposes directions for future investigations.

Correlation between the natural infection by Corynebacterium pseudotuberculosis in goats and serum progesterone levels and corpus luteum development

Caseous Lymphadenitis (CLA) is an infectious disease that affects small ruminants, and the bacterium Corynebacterium pseudotuberculosis is its etiologic agent. This disease presents a high morbidity and a great economic impact on goat farming, leading to reduced milk and meat production and reproductive losses. The available data about the influence of C. pseudotuberculosis on the reproductive system were obtained after experimental inoculations. In this way, this study aimed to evaluate the influence of the natural infection by C. pseudotuberculosis on the luteal function and serum progesterone (P₄) levels in goats. Sixteen female goats were diagnosed for the presence of C. pseudotuberculosis specific antibodies and divided into 2 groups: CLA positive and negative animals. They were submitted to estrous synchronization, followed by controlled mating. Corpus luteum and serum levels of P₄ were evaluated on the 7th and 20th days after mating (D7 and D20). The ultrasonographic results were not statistically different between the 2 groups, as well as serum P₄ levels on D7. However, a significant increase in serum P₄ levels on the CLA positive group was identified on D20, along with a significant correlation between C. pseudotuberculosis specific antibody production, and P₄ serum levels. The result of this study indicates that the infection by C. pseudotuberculosis may influence the reproductive status of female goats through an enhanced production of progesterone.

Identification and analysis of novel endometriosis biomarkers via integrative bioinformatics

Endometriosis is a gynecological disease prevalent in women of reproductive age, and it is characterized by the ectopic presence and growth of the eutopic endometrium. The pathophysiology and diagnostic biomarkers of endometriosis have not yet been comprehensively determined. To discover molecular markers and pathways underlying the pathogenesis of endometriosis, we identified differentially expressed genes (DEGs) in three Gene Expression Omnibus microarray datasets (GSE11691, GSE23339, and GSE7305) and performed gene set enrichment analysis (GSEA) and protein-protein interaction (PPI) network analyses. We also validated the identified genes via immunohistochemical analysis of tissues obtained from patients with endometriosis or healthy volunteers. A total of 118 DEGs (79 upregulated and 39 downregulated) were detected in each dataset with a lower (fold change) FC cutoff (log2|FC| > 1), and 17 DEGs (11 upregulated and six downregulated) with a higher FC cutoff (log2|FC| > 2). KEGG and GO functional analyses revealed enrichment of signaling pathways associated with inflammation, complement activation, cell adhesion, and extracellular matrix in endometriotic tissues. Upregulation of seven genes (C7, CFH, FZD7, LY96, PDLIM3, PTGIS, and WISP2) out of 17 was validated via comparison with external gene sets, and protein expression of four genes (LY96, PDLIM3, PTGIS, and WISP2) was further analyzed by immunohistochemistry and western blot analysis. Based on these results, we suggest that TLR4/NF-κB and Wnt/frizzled signaling pathways, as well as estrogen receptors, regulate the progression of endometriosis. These pathways may be therapeutic and diagnostic targets for endometriosis.

Assessment of Sensitivity and Profitability of an Intravaginal Sensor for Remote Calving Prediction in Dairy Cattle

One critical point of dairy farm management is calving and neonatal first care. Timely calving assistance is associated with the reduction of calf mortality and postpartum uterine disease, and with improved fertility in dairy cattle. This study aimed to evaluate the performance and profitability of an intravaginal sensor for the prediction of stage II of labor in dairy farms, thus allowing proper calving assistance. Seventy-three late-gestating Italian Holstein cows were submitted to the insertion of an intravaginal device, equipped with light and temperature sensors, connected with a Central Unit for the commutation of a radio-signal into a cell phone alert. The remote calving alarm correctly identified the beginning of the expulsive phase of labor in 86.3% of the monitored cows. The mean interval from alarm to complete expulsion of the fetus was 71.56 ± 52.98 min, with a greater range in cows with dystocia (p = 0.012). The sensor worked correctly in both cold and warm weather conditions, and during day- or night-time. The intravaginal probe was well tolerated, as any cow showed lesions to the vaginal mucosa after calving. Using sex-sorted semen in heifers and beef bull semen in cows at their last lactation, the economic estimation performed through PrecisionTree™ software led to an income improvement of 119 € and 123 €/monitored delivery in primiparous and pluriparous cows, respectively. Remote calving alarm devices are key components of "precision farming" management and proven to improve animal welfare, to reduce calf losses and to increase farm incomes.

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

This experiment was performed to assess reliability of the cytobrush-cytology method (CCM) in diagnosis of subclinical endometritis (SCE) using the biopsy-histopathology method (BHM) as a reference in late lactating dairy cows. Reproductive organs were collected from 115 slaughtered multiparous crossbred cows culled due to infertility 398 ± 135 days subsequent to parturition. Samples were collected from the dorsal part of the corpus uteri for analyses. Inflammation status was graded histopathologically based on the cell percentages [(neutrophils, eosinophils, lymphocytes (LYM), macrophages (MAC), and plasma cells)]. Data were subjected to Friedman's test for group comparisons (method and diagnosis), concordance correlation and chi-square tests for consistency of results among methods, and the receiver operating characteristics curve analysis for reliability of the CCM. Percentages of LYM (2.67x) and MAC (3.00x) were greater when evaluated using BHM than with CCM (P < 0.05 for both). The agreement (Cohen's κ value) of results among methods was 0.79 ± 0.06. The sensitivity (Se) and specificity (Sp) of the CCM for defining endometrial inflammation were 79.3% and 100%, respectively. Among inflammatory cells, proportions of LYM and MAC in the CCM had merit for evaluation of uterine inflammation, with an Se of 74.1 and 84.5 and an Sp of 93.0 and 75.4 at the cut-off > 4 and > 0, respectively. The results indicate the CCM may be used in the diagnosis of SCE when the LYM and MAC percentages are considered in chronically infertile cows in the later stages of the lactational period.

MicroRNA Bta-miR-24-3p Suppressed Galectin-9 Expression through TLR4/NF-ĸB Signaling Pathway in LPS-Stimulated Bovine Endometrial Epithelial Cells

Endometritis is a major infectious disease affecting dairy development. MicroRNAs are recognized as critical regulators of the innate immune response. However, the role and mechanism of Bta-miR-24-3p in the development of endometritis are still unclear. This study aimed to investigate the effect of Bta-miR-24-3p on the inflammatory response triggered by lipopolysaccharide (LPS) and to clarify the possible mechanism. LPS-treated bovine endometrial epithelial cells (BEECs) were cultured to investigate the role of Bta-miR-24-3p. The expression levels of Bta-miR-24-3p were downregulated, and galectin-9 (LGALS9) were measured by quantitative real-time polymerase chain reaction. The LPS-induced inflammatory response was assessed by the elevated secretion of inflammatory cytokines measured by using enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction. Activation of nuclear factor-κB (NF-κB) and TLR4 pathway was assessed by Western blot. The interaction between Bta-miR-24-3p and LGALS9 was validated by bioinformatics analysis and a luciferase reporter assay. LPS-induction in BEECs with Bta-miR-24-3p was overexpressed leads inhibition of pro-inflammatory cytokines, LGALS9 expression, and TLR4/NF-ĸB pathway deactivation. Knockdown of LGALS9 inhibited the LPS-induced inflammatory response in BEECs. LGALS9 was validated as a target of Bta-miR-24-3p. Cloned overexpression of LGALS9 failed to alter the effect of Bta-miR-24-3p on the inflammatory response in BEECs. Overall, Bta-miR-24-3p attenuated the LPS-induced inflammatory response via targeting LGALS9. The immunotherapeutic stabilisation of Bta-miR-24-3p could give a therapeutic option for endometritis and other disorders commonly associated with endometritis, suggesting a novel avenue for endometritis treatment.

Bacterial communities from vagina of dairy healthy heifers and cows with impaired reproductive performance

Vaginal microenvironment plays a significant role in bovine fertility since its resident microorganisms interact with the host mucosa and constitutes the first barrier against ascending pathogens in the reproductive tract. In this study, the vaginal microbiome of healthy heifers (H) and cows with impaired reproductive performance, metritis complex (MT) or repeat breeders (RB), was assessed using a 16S rRNA gene sequencing approach. Analysis revealed that even though a vaginal microbiological guild (Firmicutes, Bacteroidetes, Proteobacteria, Tenericutes, Fusobacteria and Actinobacteria) was shared among healthy heifers and cows with uterine disease; further analysis at genus level showed significant differences depending on the reproductive health status. The relative abundances of recognized uterine pathogens such as Bacteroidetes, Fusobacterium and Helcococcus were higher in MT when compared with H and RB; therefore, their presence in vagina can be considered as a risk factor for fertility. The present study describes for the first time, the composition of native bacterial communities in the vagina of cows undergoing the repeat breeding syndrome (RBS), and reports an association between this disease and the presence of Porphyromonas and unassigned genera of the Pasteurellaceae family. In addition, this work highlights the bacteria associated with a healthy vagina: genera from the families Lachnospiraceae, Rikenellaceae and the genera Acinetobacter, Bacillus, Oscillospira, CF231 and 5-7NS. Results highlighted herein, signify the potential of the evaluation of the bovine vaginal microbiome to future design therapeutic interventions to improve pregnancy rates however, further research is needed to elucidate the balance of bacterial species resulting in an optimal reproductive health.

A pilot monitoring strategy for post-partum disease in an Australian dairy herd

AIMS

To design a monitoring strategy that could be applied to regular veterinary visits to dairy farms to assess the prevalence and association between health conditions (uterine disease, hyperketonaemia and suboptimal body condition score) when diagnosed and treated at 1-7 days post-calving (DPC) and then re-examined at 28-35 DPC.

METHODS

This study evaluated data from 187 high-yielding dairy cows (21 primiparous, 166 multiparous) on one South Australian dairy farm on two occasions; Visit A which was 1-7 DPC and Visit B which was 28-35 DPC. On each visit, the nature of vaginal discharge, concentration of beta-hydroxybutyrate (BOH) in blood and BCS were recorded and assigned a clinical score. This was converted to a categorical outcome denoting the presence or absence of an abnormal health event, namely metritis or endometritis, hyperketonaemia (BOH concentration ≥1.2 mm/L) and suboptimal body condition score (>0.5 from optimum score). Cows with uterine disease or hyperketonaemia at either visit were treated. The prevalence of abnormal health events at each visit was determined and the association between the prevalence of disease at Visit A and Visit B (following appropriate treatment at Visit A) was measured using regression analysis.

RESULTS

The prevalence of abnormal vaginal discharge, hyperketonaemia and suboptimal BCS at Visits A and B were 26%, 7%, 35% and 25%,16%, 33% respectively. A higher proportion of primiparous cows (Visit A: 0.86 (95% CI = 0.70-1.00); Visit B: 0.95 (95% CI = 0.86-1.00)) were found to have suboptimal BCS at both visits compared to multiparous cows (Visit A: 0.28 (95% CI = 0.20-0.35); Visit B: 0.24 (95% CI = 0.17-0.32)). A higher prevalence of hyperketonaemia at Visit B for multiparous compared to primiparous cows (19 (95% CI = 12-25)% vs. 0 (95% CI = 0-17) respectively) was identified. An increase in clinical discharge score at Visit A increased the odds of purulent vaginal discharge at Visit B (OR = 1.77 (95% CI = 1.31-2.40)). Failing to calve at target BCS was strongly associated with cows missing target BCS at Visit B (OR = 5.77 (95% CI = 2.35-13.11)) and for every unit increase in BCS at Visit A, BCS at Visit B increased by 0.40 (95% CI = 0.26-0.53).

CONCLUSIONS AND CLINICAL RELEVANCE

This study describes a pilot monitoring strategy for clinical parameters indicative of post-partum disease at 1-7 and 28-35 DPC. Determining the herd prevalence of these conditions will enable tracking of herd disease status over time.Abbreviations: BCS: Body condition score; BOH: Beta-hydroxybutyrate; DPC: Days post-calving; NEFA: Non-esterified fatty acids; SCHK: Subclinical hyperketonaemia.

NRF2 Exerts Anti-Inflammatory Effects in LPS-Induced gEECs by Inhibiting the Activation of the NF-κB

Nuclear factor E2-related factor 2 (NRF2) plays an anti-inflammatory role in several pathological processes, but its function in lipopolysaccharide- (LPS-) induced goat endometrial epithelial cells (gEECs) is still unknown. We designed a study to investigate the function of NRF2 in LPS-induced gEECs. LPS was found to increase the NRF2 expression and the nuclear abundance of NRF2 in gEECs in a dose-dependent manner. NRF2 knockout (KO) not only increased the expression of LPS-induced proinflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-8) but also increased the expression of TLR4, p-IκBα/IκBα, and p-p65/p65 proteins. Immunoprecipitation experiments showed that NRF2 directly binds to p65 in the nucleus and inhibits the binding of p65 to downstream target genes (TNF-α, IL-1β, IL-6, and IL-8). Even though a NF-κB/p65 inhibitor (PDTC) reduced the LPS-induced NRF2 expression and nuclear abundance of NRF2, overexpressing TNF-α reversed the inhibitory effects of PDTC on the NRF2 expression and on its abundance in the nucleus. Similarly, knockdown of the proinflammatory cytokines (TNF-α, IL-1β, IL-6, or IL-8) significantly decreased the LPS-induced NRF2 expression and NRF2 in the nucleus. In conclusion, our data suggest that proinflammatory cytokines induced by LPS through the TLR4/NF-κB pathway promote the NRF2 expression and its translocation into the nucleus. Our work also suggests that NRF2 inhibits the expression of proinflammatory cytokines by directly binding to p65.

The immunoexpression patterns of fibroblast growth factors in the pregnant and postpartum rat ovary

Fibroblast growth factors (FGFs) are polypeptides involved in the regulation of oogenesis and folliculogenesis by inducing ovarian mitogenic, homeostatic and angiogenic activity. This study was aimed at determining the localisation of FGF ligands (FGF1 and FGF2) and FGF receptor 2 (FGFR2) in the rat ovary by immunohistochemical analyses, at pregnancy and the postpartum period. During pregnancy and the postpartum period, positive FGF1 immunoreactions were observed in the nucleus and cytoplasm of germinative epithelial cells, granulosa cells of follicles in different developmental stages, theca interna cells, interstitial cells, luteal cells and atretic follicles. FGF2 immunoreactivity was strong in the cytoplasm of the endothelial cells and smooth muscle cells of the ovarian blood vessels and in the smooth muscle cells of the ovarian cortex and medulla. Strong FGFR2 immunoreactivity was observed in the stromal cells surrounding the blood vessels and rete ovarii. Immunoreaction intensity of the FGF1, FGF2 and FGFR2 had relatively similar abundances between the periods examined. Considering that FGFs act as local regulators in oogenesis, folliculogenesis, follicular atresia, ovulation, corpus luteum formation and regression and angiogenesis, this study supports the idea that FGFs may also be involved in these physiological functions in rat ovaries during pregnancy and postpartum period.

Characterization of Reproductive Microbiota of Primiparous Cows During Early Postpartum Periods in the Presence and Absence of Endometritis

Endometritis has a major impact on fertility in postpartum dairy cows. Since previous studies showed an association between reproductive microbiota and perinatal disease, we monitored both bovine uterine and vaginal microbiota in primiparous cows to elucidate the effect of early postpartum microbiota on endometritis. Uterine and vaginal samples were collected at time points from pre-calving to 35 days postpartum (DPP), and analyzed by 16S rRNA sequencing, combined with ancillary bacterial culture. A total of seven healthy cows and seven cows diagnosed with endometritis on 35 DPP were used in the current study. The uterine and vaginal microbiota showed a maximum of 20.1% shared amplicon sequence variants (ASVs) at linked time points. 16S rRNA based analysis and traditional culture methods revealed that Trueperella showed a higher abundance in both uterus and vagina of the endometritis group compared to the healthy group on 21 DPP (U-test p < 0.05). Differential abundance analysis of the uterine microbiota showed that Enterococcus and six bacterial genera including Bifidobacterium were unique to the healthy group on the day of calving (0 DPP) and 28 DPP, respectively. In contrast, Histophilus and Mogibacteriaceae were characteristic bacteria in the vagina pre-calving in cows that later developed endometritis, suggesting that these bacteria could be valuable to predict clinical outcomes. Comparing the abundances of bacterial genera in the uterine microbiota, a negative correlation was observed between Trueperella and several bacteria including Lactobacillus. These results suggest that building an environment where there is an increase in bacteria that are generally recognized as beneficial, such as Lactobacillus, may be one possible solution to reduce the abundance of Trueperella and control endometritis.

Calving Management: A Questionnaire Survey of Veterinary Subject Matter Experts and Non-Experts

Simple Summary

We designed a questionnaire and asked two groups of veterinarians: (1) subject matter experts, who had published on calving management and (2) veterinary practitioners) for their opinion about aspects of calving management. Participants recommended to differentiate between the two stages of parturition and emphasized signs of imminent parturition, such as “restlessness” and “visibility of fetal parts”. There was no consensus on the right time to move the cow to the maternity pen. Almost half of the respondents recommended a 6-h observation interval for prepartum cows in the maternity pen. The two veterinary groups differed little in their knowledge of calving management.

Abstract

Accurate detection of the onset of parturition is a key factor in the prevention of dystocia. In order to establish current best practice recommendations for calving management, we asked subject matter experts (SME) who had published on calving management (by online survey, n = 80) and non-SMEs, veterinary practitioners (by workshop survey, n = 24) for their opinions. For this, we designed a questionnaire on the significance of signs of imminent parturition (SIP), the frequency of calving observation, and influencing factors for the timing of cow movement to a maternity pen. The response rate was 67.5% in the online survey and 100% in the workshop survey. The majority (89.7%) of all respondents agreed that it is beneficial for successful calving management to differentiate between stage I and II of parturition. Of 12 signs of imminent parturition (for stage I and II), “restlessness” and “visibility of fetal parts in vulva” were cited by 56.5% and 73.3% of SME and non-SME respondents, respectively. There was no consensus on the right time to move the cow to the maternity pen; recommendations varied from one to over 21 days. Almost half of the respondents (45.7%) recommended a 6-h observation interval for prepartum cows in the maternity pen. This study identified a strong consensus on the SIP and how and when to observe cows prior to parturition. SMEs and non-SMEs provided broadly similar recommendations, while the SMEs and the non-SMEs differed significantly in the number of publications on calving they authored, they differed little in their knowledge of calving management.

Investigating the Reciprocal Interrelationships among the Ruminal Microbiota, Metabolome, and Mastitis in Early Lactating Holstein Dairy Cows

Simple Summary

Dairy cow mastitis is an inflammatory disease often caused by bacterial infections. In the present study, we identified the ruminal microbial biomarkers and metabolites of mastitis in dairy cows. The investigation of the reciprocal interrelationships among the ruminal microbiota, metabolome, and mastitis revealed that short-chain fatty acid (SCFA)-producing microflora and the metabolites related to anti-inflammation and antibacterial activity were significantly higher in healthy cows than in those with mastitis. The identified potential species and metabolites might provide a novel perspective to assist in targeting the ruminal microbiota with preventive/therapeutic strategies against mastitis in the future.

Abstract

Mastitis in dairy cow significantly affects animal performance, ultimately reducing profitability. The reciprocal interrelationships among ruminal microbiota, metabolome, and mastitis combining early inflammatory factors (serum proinflammatory cytokines) in lactating dairy cows has not been explored, thus, this study evaluated these reciprocal interrelationships in early lactating Holstein dairy cows to identify potential microbial biomarkers and their relationship with ruminal metabolites. The ruminal fluid was sampled from 8 healthy and 8 mastitis cows for the microbiota and metabolite analyses. The critical ruminal microbial biomarkers and metabolites related to somatic cell counts (SCC) and serum proinflammatory cytokines were identified by the linear discriminant analysis effect size (LEfSe) algorithm and Spearman’s correlation analysis, respectively. The SCC level and proinflammatory cytokines positively correlated with Sharpea and negatively correlated with Ruminococcaceae UCG-014, Ruminococcus flavefaciens, and Treponema saccharophilum. Furthermore, the metabolites xanthurenic acid, and 1-(1H-benzo[d]imidazol-2-yl) ethan-1-ol positively correlated with microbial biomarkers of healthy cows, whereas, xanthine, pantothenic acid, and anacardic acid were negatively correlated with the microbial biomarkers of mastitis cows. In conclusion, Ruminococcus flavefaciens and Treponema saccharophilum are potential strains for improving the health of dairy cows. The current study provides a novel perspective to assist in targeting the ruminal microbiota with preventive/therapeutic strategies against inflammatory diseases in the future.

Predisposing factors, diagnostic and therapeutic aspects of persistent endometritis in postpartum cows

A certain level of endometrial bacterial infection and inflammation is involved in bovine uterine involution during the puerperal period. Factors that hamper normal uterine involution expose the uterine environment to pathological conditions, causing different endometritis levels. The lack of proper diagnostic tools extends the time to conception. Efforts have been made to elucidate the postpartum uterine environment, including bacterial flora, changes in transient endometrial inflammation, and the pathophysiology of endometritis, to improve bovine reproductive performance. E. coli and Trueperella pyogenes in the uterus are likely to cause persistent infection, and Mycoplasma bovigenitalium infection is associated with dystocia and cytological endometritis in postpartum dairy cows. Due to the widespread use of cytobrush as a diagnostic tool for bovine subclinical endometritis (SE) that enables quantification of the degree of inflammation, we found that endometritis at week 5 postpartum was associated with delayed first ovulation. Approximately 30% of open cows have SE during the postpartum period, and cows with low blood glucose during prepartum have a high risk of developing SE. Additionally, cows with purulent vaginal discharge do not always have endometritis but only vaginitis and/or cervicitis. Intrauterine infusion of polyvinylpyrrolidone-iodine (PVP-I) improves fertility and promotes endometrial epithelial cell regeneration after inducing transient uterine inflammation, suggesting that PVP-I could be a good alternative to antibiotics. In conclusion, prepartum management to prevent glucose deficiency, prompt diagnosis to identify causative agents and intrauterine inflammation levels, and appropriate treatment to minimize antimicrobial resistance is beneficial for tackling endometritis and improving reproductive performance in bovine herds.

Prepartum level of dietary cation-anion difference fed to nulliparous cows: Acid-base balance, mineral metabolism, and health responses

Objectives were to determine the effects of 3 different levels of dietary cation-anion difference (DCAD) fed during the last 22 d of gestation to pregnant nulliparous cows on pre- and postpartum acid-base balance, mineral metabolism, and health responses. In all, 132 pregnant nulliparous Holstein cows were enrolled at 250 (248-253) d of gestation, blocked by genomic merit of energy-corrected milk yield, and assigned randomly to diets varying in DCAD: +200 (P200, n = 43), -50 (N50, n = 45), or -150 (N150, n = 44) mEq/kg of dry matter. Dietary treatments were fed until calving, after which cows received the same lactation diet for the first 100 d postpartum. Urine and blood were sampled throughout the prepartum period and in the first weeks postpartum, and urine was assessed for pH, whereas blood was analyzed for gases, measures of acid-base balance, minerals, and metabolites. Calcium (Ca) and magnesium (Mg) retention and phosphorus (P) digestibility were evaluated in the last week of gestation and first week of lactation. Incidence of diseases was evaluated for the first 100 d postpartum. Data are presented in sequence as P200, N50, N150 (LSM ± SEM). Reducing the DCAD reduced urine (8.17 vs. 6.50 vs. 5.51 ± 0.11) and blood pH (7.442 vs. 7.431 vs. 7.410 ± 0.004) and induced a state of compensated metabolic acidosis with a reduction in blood HCO₃^- (28.4 vs. 26.7 vs. 24.9 ± 0.3 mM) and partial pressure of CO₂ (41.8 vs. 40.1 vs. 39.1 ± 0.4 mmHg) prepartum. Reducing the DCAD linearly increased blood ionized Ca (iCa; 1.224 vs. 1.243 vs. 1.259 ± 0.008 mM) and serum total Ca (tCa; 2.50 vs. 2.53 vs. 2.56 ± 0.02 mM) prepartum, blood iCa on the day of calving, and serum Mg in the first days postpartum. Reducing the DCAD linearly increased the apparent absorption of Ca (12.9 vs. 19.0 vs. 20.9 ± 1.4 g/d) and Mg (7.0 vs. 9.9 vs. 10.4 ± 1.4 g/d) prepartum, but apparent retention of both Ca (13.9 g/d) and Mg (3.4 g/d) did not differ with treatment. Treatment did not affect digestibility of P pre- or postpartum or retention of Ca or Mg postpartum. Treatment did not affect the incidence or prevalence of subclinical hypocalcemia, hepatic composition, or the prevalence of fatty liver. Reducing the DCAD had a quadratic effect on incidence of fever (46.5 vs. 17.6 vs. 33.9 ± 7.0%), uterine diseases (36.3 vs. 25.6 vs. 46.0 ± 7.3%), and morbidity (41.4 vs. 28.1 vs. 55.6 ± 7.3%). Feeding a diet with -50 mEq/kg of dry matter promoted moderate changes in acid-base balance, altered mineral metabolism, and benefited health of nulliparous cows; however, further reducing the DCAD to -150 mEq/kg negated the benefits to health.

Association of intrauterine presence of Lactobacillus spp. with inflammation and pathogenic bacteria in the uterus in postpartum dairy cows

The aim of this study was to clarify the influence of Lactobacillus spp. on the degree of endometrial inflammation in the postpartum period and the relationship between Lactobacillus spp. and pathogenic bacteria in the endometrium of postpartum dairy cows. Endometrial samples were collected from 41 Holstein-Friesian cows at 4 and 8 weeks postpartum using cytobrushes for polymorphonuclear neutrophil (PMN) count and bacterial culture to isolate Lactobacillus spp., Escherichiacoli, and Trueperella pyogenes. The 4-week samples were divided into four groups (E+L+), (E+L−), (E−L+), (E−L−) according to whether endometritis was diagnosed (E+) and Lactobacillus spp. was isolated (L+). The diagnostic criterion for cytological endometritis was > 18% PMN. The average PMN% in the E+L+ group was lower than that in the E+L-group (P < 0.05) at 8 weeks postpartum. There were no significant correlations between the number of colonies of Lactobacillus spp. and E. coli or between that of Lactobacillus spp. and T. pyogenes. Lactobacillus spp. could reduce PMN% in dairy cows with endometritis during the puerperal period. In conclusion, the intrauterine presence of Lactobacillus spp. may have a positive effect on uterine involution in postpartum dairy cows.