Comparative biochemical profiles, production and reproduction status of the post-partum dairy cows with and without purulent vaginal discharge

Treatment of postpartum endometritis induced by multidrug-resistant bacterial infection in dairy cattle by green synthesized zinc oxide nanoparticles and in vivo evaluation of its broad spectrum antimicrobial activity in cow uteri

Postpartum endometritis significantly affects the health and productivity of cattle, causing significant economic loss that is speculated to exceed billions of dollars annually. Treatment of postpartum endometritis, which is linked to various bacterial infections in the uterus after delivery and has an alarmingly high risk of antibiotic treatment failure for unidentified reasons, represents a great challenge. Several studies have demonstrated that various disease complications, such as multidrug-resistant (MDR) bacterial strains, prolonged infection treatment, and increased mortality risk, have emerged as a result of the extensive use of antibiotics to treat uterine infections and other microbial-related diseases. Recent research has led to the development of zinc oxide nanoparticles (ZnO NPs) that exhibit broad-spectrum antibacterial efficacy against bacterial pathogens, including MDR bacteria, without producing mutants that are resistant to zinc oxide (ZnO). In the present work, we biologically synthesized ZnO NPs from a green natural source of Helianthus annuus seeds for the treatment of endometritis caused by MDR bacterial strains in dairy cattle. We examined ZnO's potential as a substitute antimicrobial agent to treat cow endometritis by testing its ability to sustain potent antimicrobial activity against pathogenic bacteria, including Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), in cow uteri. Among uterine bacteria, ZnO significantly decreased E. coli and S. aureus, which are known pathogenic bacteria within the uterus and achieved a high cure rate that was associated with the induction of estrous and pregnancy. Taken together, our observations of ZnO's broad range of antibacterial activity in-vivo with an animal model and subsequent evaluations of its therapeutic efficacy in cows with endometritis shed light on its potential to be used as a substitute antimicrobial agent for the treatment of uterine illness.

Evaluation of clinical and subclinical endometritis impacts on the reproductive performance and milk production of dairy cows in Brazilian herds

Clinical endometritis (CE) and subclinical endometritis (SE) are two of the main uterine diseases in dairy cows during the puerperium period that can directly affect milk production and fertility in dairy herds. The first objective of this study was to investigate the effects of the CE and SE on the subsequent reproductive performance and milk production of dairy cows in Brazilian herds, and the second objective was to evaluate the reproductive performance and milk production of dairy cows according to the positive or negative isolation of bacteria in the uterine environment. A total of 279 lactating Holstein dairy cows (28-33 days in milk) from six commercial farms were studied. These were classified into three groups: healthy cows (without CE and SE, n = 161), cows with CE (vaginal discharge score = 3 and ≥18% PMNL, n = 83) and cows with SE (absence of signs of CE and >18% PMNL, n = 35). According to the presence of bacteria isolated from the uterine environment, the animals were classified as healthy cows (n = 161), CE cows with positive (n = 68) and negative (n = 15) bacterial isolation; and SE cows with positive (n = 21) and negative (n = 14) bacterial isolation. Cows with CE (20.5%) and SE (31.4%) had a lower (p < .05) conception rate at first AI than healthy cows (47.8%). Furthermore, both cows with CE (3.1) and SE (2.8) needed more service to become pregnant than healthy cows (1.7) and more days to be pregnant (50.3 days in CE and 43.1 days in SE than healthy group; p < .001). Cows with CE (23.8 kg) and SE (23.7 kg) produced less milk than healthy cows on the day of sampling (28.2 kg); however, milk production during 305 DIM of cows with CE and SE was not impaired when compared to healthy cows. The logistic regression showed that parity, body condition score, 305 days milk production, last calving (eutocia or dystocia), twin birth and stillbirth were not associated with the incidence of CE and SE. In addition, we highlight that cows with CE and SE, but with negative bacteria isolation, did not have reproductive performance and milk production impaired during the postpartum period. These results support that the use of antibiotics would not be beneficial in these cows, contributing to the strategic and rational use of antibiotic therapy on dairy farms.

In vitro effects of cinnamon, oregano, and thyme essential oils against Escherichia coli and Trueperella pyogenes isolated from dairy cows with clinical endometritis

Clinical endometritis causes serious economic losses in dairy farms, mainly due to its negative health impact on fertility and milk production, as well as the additional costs of medicines used to treat the affected animals. The therapy for uterine diseases is principally performed with antibiotic treatment; however, its indiscriminate use in dairy herds can favor the increase in the resistance of pathogenic bacteria, leading to treatment failures. In this regard, the use of unconventional treatment may be a good option to reduce the use of antimicrobials in milk production. The objective of the present study was to evaluate the antibacterial activity of cinnamon, oregano, and thyme essential oils, and their combinations, against bovine uterine pathogens. The antibacterial activities of these essential oils were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC), and Fractional Inhibitory Concentration (FIC) indices against Escherichia coli and Trueperella pyogenes, which were isolated from dairy cows with clinical endometritis. Among the essential oils evaluated, the lowest MIC and MBC values observed were obtained with cinnamon essential oil alone. The association among essential oils showed different kinds of interactions, and in some situations, antagonism was observed. This study demonstrated a promising antimicrobial activity of cinnamon's essential oil, indicating that it has excellent potential to be explored as a possible alternative in the treatment of clinical endometritis in dairy cows.

Characterization of metabolic profile, health, milk production, and reproductive outcomes of dairy cows diagnosed with concurrent hyperketonemia and hypoglycemia

The objective of this prospective cohort study was to characterize the metabolic profile, health, milk production, and reproductive outcomes of cows diagnosed with hyperketonemia (HK; β-hydroxybutyrate ≥1.2 mmol/L), hypoglycemia (HG; glucose ≤2.2 mmol/L), or concurrent HK and HG (HKHG). Glucose and β-hydroxybutyrate concentrations in whole blood were assessed using a handheld device (Precision Xtra, Abbott Laboratories) in lactating dairy cows (n = 2,418) between 3 and 9 d postpartum. Cows were categorized into 4 groups: no HK or HG (healthy; Norm = 1,821), HK only (HK = 232), HG only (HG = 161), and concurrent HK and HG (HKHG = 204). Subsequent milk production, along with health and reproductive outcomes, as recorded by farm personnel, were analyzed according to metabolic category. Serum collected on the day of cow-side diagnosis of hyperketonemia and hypoglycemia was evaluated for total calcium (tCa), magnesium (Mg), nonesterified fatty acids (NEFA), triglycerides (TG), and urea using an automated chemistry analyzer (Randox Daytona; Randox Laboratories Ltd.). Statistical analysis was carried out using SAS version 9.4 (SAS Institute Inc.). Hyperketonemia in multiparous cows was associated with greater incidence of metabolic abnormalities (hypomagnesemia, hypocalcemia, and elevated NEFA and urea). Hyperketonemia in primiparous and multiparous cows led to increased adverse health events (culling rate, retained fetal membranes, puerperal metritis, clinical ketosis, left displaced abomasum) relative to Norm cows. Multiparous cows with HKHG had fewer metabolic disturbances (hypomagnesemia, hypocalcemia, elevated NEFA) than HK cows. Cows with HKHG had an increased incidence of clinical ketosis and left displaced abomasum relative to Norm cows. Cows with HG had similar metabolic profiles to Norm cows and had lower incidence of retained fetal membranes and puerperal metritis than cows with HK. Multiparous cows with HG produced more milk than Norm cows from wk 10 to 20, whereas multiparous cows with HK produced less milk than Norm cows. For primiparous cows, HK did not have a negative effect on milk production compared with Norm cows.

Evaluation of Host Depletion and Extraction Methods for Shotgun Metagenomic Analysis of Bovine Vaginal Samples

The reproductive tract metagenome plays a significant role in the various reproductive system functions, including reproductive cycles, health, and fertility. One of the major challenges in bovine vaginal metagenome studies is host DNA contamination, which limits the sequencing capacity for metagenomic content and reduces the accuracy of untargeted shotgun metagenomic profiling. This is the first study comparing the effectiveness of different host depletion and DNA extraction methods for bovine vaginal metagenomic samples. The host depletion methods evaluated were slow centrifugation (Soft-spin), NEBNext Microbiome DNA Enrichment kit (NEBNext), and propidium monoazide (PMA) treatment, while the extraction methods were DNeasy Blood and Tissue extraction (DNeasy) and QIAamp DNA Microbiome extraction (QIAamp). Soft-spin and QIAamp were the most effective host depletion method and extraction methods, respectively, in reducing the number of cattle genomic content in bovine vaginal samples. The reduced host-to-microbe ratio in the extracted DNA increased the sequencing depth for microbial reads in untargeted shotgun sequencing. Bovine vaginal samples extracted with QIAamp presented taxonomical profiles which closely resembled the mock microbial composition, especially for the recovery of Gram-positive bacteria. Additionally, samples extracted with QIAamp presented extensive functional profiles with deep coverage. Overall, a combination of Soft-spin and QIAamp provided the most robust representation of the vaginal microbial community in cattle while minimizing host DNA contamination.

IMPORTANCE In addition to the host tissue collected during the sampling process, bovine vaginal samples are saturated with large amounts of extracellular DNA and secreted proteins that are essential for physiological purposes, including the reproductive cycle and immune defense. Due to the high host-to-microbe genome ratio, which hampers the sequencing efficacy for metagenome samples and the recovery of the actual metagenomic profiles, bovine vaginal samples cannot benefit from the full potential of shotgun sequencing. This is the first investigation on the most effective host depletion and extraction methods for bovine vaginal metagenomic samples. This study demonstrated an effective combination of host depletion and extraction methods, which harvested higher percentages of 16S rRNA genes and microbial reads, which subsequently led to a taxonomical profile that resembled the actual community and a functional profile with deeper coverage. A representative metagenomic profile is essential for investigating the role of the bovine vaginal metagenome for both reproductive function and susceptibility to infections.

Assessment of the main pathogens associated with clinical and subclinical endometritis in cows by culture and MALDI-TOF mass spectrometry identification

Clinical endometritis (CE) and subclinical endometritis (SCE) are diseases that affect dairy cows during the puerperium, causing negative effects on the animals' milk production and fertility. The objective of this study was to assess the main bacteria related to cases of CE and SCE from uterine samples of dairy cows in Brazilian herds. Selective and differential media were used for isolation of aerobic and anaerobic bacteria and further MALDI-TOF mass spectrometry (MS) identification. A total of 279 lactating dairy cows with 28 to 33 d in milk from 6 commercial farms were evaluated. Initially, cows were classified in 3 groups: cytologic healthy cows (n = 161), cows with CE (n = 83), and cows with SCE (n = 35). Healthy animals presented 97 species, followed by the CE group with 53 identified species, and SCE cows presented only 21 bacterial species. We found a significantly higher isolation rate of Trueperella pyogenes in CE (26.5%) cows compared with healthy and SCE cows. Some anaerobic species were exclusively isolated from the CE group, even though they presented lower frequency. Interestingly, 18.1% of samples from CE cows and 40% of SCE cows were negative to bacterial isolation. Despite the use of culture-dependent methods instead of molecular methods, the present study enabled the identification of a complex community of 127 different species from 48 genera, composed of aerobic and anaerobic bacterial species among the 3 different animal groups. The method of sample collection, culture, and identification by MALDI-TOF MS were essential for the success of the analyses.

Clinical endometritis with Trueperella pyogenes reduces reproductive performance and milk production in dairy cows

The aim of this study was to identify the impact of Trueperella pyogenes in cows with clinical endometritis (CE) on reproductive performance and milk production in affected cows. In total, 230 lactating Holstein dairy cows from six commercial dairy herds were sampled once between 28 and 33 days post-partum. Cows included in the present study did not receive antibiotic or anti-inflammatory treatments prior to the experimental period. Clinical endometritis (CE) was characterized as cow with vaginal mucus score = 3 (>50% of purulent vaginal discharge) and >18% polymorphonuclear neutrophilic leukocyte (PMNL). The body condition scores (BCS) and milk production were evaluated at the time of enrolment. The identification of isolated bacteria was carried out through the analysis of MALDI-TOF MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry). According to uterine health, three groups of dairy cows were formed: healthy control cows without T. pyogenes (n = 147), CE cows with T. pyogenes (n = 22) and CE cows without T. pyogenes (n = 61). CE cows with T. pyogenes had lower BCS, milk production and conception at first AI (p < .01) than CE cows without T. pyogenes and control cows. Furthermore, CE cows with T. pyogenes had higher (p < .01) service per pregnancy and had greater (p < .01) days to get pregnant than CE cows without T. pyogenes and control cows. This study demonstrates that CE cows with T. pyogenes had impaired reproductive performance and milk production when compared to cows without CE and CE cows without T. pyogenes. This information can contribute to a strategic treatment in cows affected by clinical endometritis, favouring the rational use of antibiotics on dairy farms.

Body status and blood metabolites profiles during resumption of postpartum ovarian activity in yak (Poephagus grunniens)

We examined the changes in body weight (BW), back-fat thickness (BFT) and blood metabolites in relation to postpartum (PP) ovarian activity status in twenty female yaks raised under semi-intensive system. BFT and ovarian activities, like follicle development, ovulation (OV) and corpus luteum (CL) development, were monitored from 4 to 15 weeks (wk) PP using ultrasonography. Resumption of ovarian activity was confirmed with ovulation of dominant follicle (DF) and subsequent CL development, and >1 ng/ml progesterone concentration in blood plasma sample after 1week of ovulation. Yaks were further classified as cyclic (with CL), acyclic (without CL), and cystic (with >25 mm follicular cyst; FC). Within 20 weeks PP, 60% yaks resumed cyclic ovarian activity, while 25% failed to initiate cycling activity, and 15% developed follicular cysts. In all categories of yak, BW gradually decreased (p < .05) till nadir; however, nadir reached earlier (p < .05) in acyclic yaks. BFT differed (p < .05) among the yak groups, but it tended to be higher in cyclic yaks as compared to acyclic and cystic. No difference (p > .05) in non-esterified fatty acids (NEFA) values was found among the different categories of yaks, whereas, beta-hydroxy butyrate (BHB) levels were higher in cystic animals as compared to acyclic and cyclic. Blood glucose levels decreased in all yaks during initial 2 weeks after calving. Our findings suggest that yaks with low BW, BFT and glucose levels, and higher BHB values were at risk of delayed resumption of ovarian activity and concomitant development of follicular cysts.

Exosomal Cargo May Hold the Key to Improving Reproductive Outcomes in Dairy Cows

The reproductive status of dairy cows remains a challenge for dairy farmers worldwide, with impaired fertility linked to a significant reduction in herd profitability, due in part to impaired immunity, increased metabolic pressure, and longer postpartum anestrous interval (PPAI). Exosomes are nanovesicles released from a variety of cell types and end up in circulation, and carry proteins, bioactive peptides, lipids, and nucleic acids specific to the place of origin. As such, their role in health and disease has been investigated in humans and animals. This review discusses research into exosomes in the context of reproduction in dairy herds and introduces recent advances in mass-spectrometry (MS) based proteomics that have a potential to advance quantitative profiling of exosomal protein cargo in a search for early biomarkers of cattle fertility.

Metritis in dairy cows is preceded by alterations in biochemical profile prepartum and at parturition

Metritis in dairy cows is classified as a puerperal disease that affects all layers of the uterine epithelium and occurs during the first 21 days after parturition. The objectives of this study were to identify potential predictive biomarkers of metritis, to monitor the biochemical profile of pre-metritic dairy cows, and to evaluate the reproductive performance of dairy cows with metritis. Fifty-five cows without metritis and fifteen cows that showed clinical signs of metritis were enrolled in this study. Blood samples were collected at -21, -14 and - 7 days before calving and at parturition and assayed for urea, creatinine, aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), total cholesterol, fibrinogen, total calcium, β-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFA) concentrations. Serum fibrinogen on 21, 14 and 7 days prepartum and at parturition was the strongest discriminator between metritic and control cows. Moreover, metritic cows had lower (P < 0.05) concentrations of urea, creatinine, cholesterol and calcium and higher (P < 0.05) serum AST, GGT activities, and serum fibrinogen, BHB and NEFA concentrations when compared to control cows. The number of days to first ovulation, insemination, services per pregnancy and days to pregnancy were greater (P < 0.05) for metritic cows than the control group, and the follicle size was smaller (P < 0.05) for metritic cows than the control group. Our results indicate alterations in the biochemical profile of dairy cows with metritis and the negative impact on the reproductive performance of metritic cows raised in tropical conditions. In addition, this study showed that the serum fibrinogen could be used as screening biomarkers to indicate cows that might have metritis during the postpartum period.

Changes in antioxidant enzyme activities and metabolic parameters in dairy cows during different reproductive periods

Our study aimed to monitor the alterations in antioxidant enzyme activities and the metabolic profile parameters and their relationships in dairy cows during different reproductive stages (gestational-, dry-, pre- and post-partum). The collection of blood samples from thirty healthy pregnant Holstein cows took place at a commercial dairy farm, between September 2015 and June 2016. The cows covered eight different reproductive stages (4-6 weeks before the dry period (D4-6w)), at the beginning of the dry period (D0; on day 210 of gestation), the first month of the dry period (D1m), antepartum day 8 (APd8), postpartum (PP) day 3 (PPd3), PP day 8 (PPd8), PP between 3rd-4th weeks (PP3-4w) and PP between 80 and 90 days (PP80-90d). The activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were analysed to monitor and evaluate the antioxidant system. Concentrations of beta-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), albumin, glucose, total bilirubin, cholesterol, calcium (Ca) and the enzyme activities of aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), gamma-glutamyl transferase (GGT) were also determined as metabolic profile parameters. GPx activities increased in D1m (P < 0.05) and peaked during the PP3d and PP8d periods (P < 0.0001), with values decreasing again at the PP3-4w period. The most significant change in SOD activities was detected in the PP3-4w with a significant decrease (P < 0.05). BHBA and NEFA concentrations increased significantly during the PPd3 and PPd8 periods (P < 0.05), with BHBA decreased to low values in the PP3-4w (P < 0.05). Significant positive correlations were found between BHBA, NEFA, total bilirubin and GPx (0.784, 0.874 and 0.871; P < 0.05, P < 0.01 and P < 0.01 respectively). A significant negative correlation between calcium and cholesterol and GPx was found (-0.857, P < 0.01; and -0.681, P < 0.05, respectively). As a result, a relationship was determined between blood antioxidant enzymes and metabolic parameters at different periods. High GPx and SOD activities, especially in the early period before and after parturition, is thought to be related to the adaptation of the animals to this process. The lack of adaptation abilities of animals during these periods causes many problems seen during early postpartum. Therefore, considering GPx and SOD activity measurements in pre- and postpartum periods contributes to better management of these periods and the prevention of complications.

Alterations in biochemical profiles and reproduction performance in postpartum dairy cows with metritis

The aim of the present study was to evaluate the biochemical profile and reproductive performance in postpartum dairy cows with clinical metritis. The research was carried out using performed on 213 pluriparous lactating cows from two dairy herds in southeast Brazil. Dairy cows were assigned into a group of healthy cows (n = 147) and cows with metritis (n = 66). Blood samples to assess serum albumin, cholesterol, fibrinogen, calcium, gamma-glutammyltransferase (GGT), aspartate aminotransferase (AST) and β-hydroxybutyrate (BHBA) concentrations were performed on day 8 ± 2 postpartum. Metritic cows had lower (p < .05) serum albumin, cholesterol and calcium concentration, and higher (p < .05) GGT and AST activity, and BHBA and fibrinogen concentrations when compared to the healthy group. The calving-to-conception interval and services per pregnancy were higher in metritic cows (p < .01) than in healthy cows and the conception rate at first service was lower in metric group (p < .01). Variable importance in projection plots demonstrated that cholesterol was the main discriminator between metritic and healthy cows. Our results indicated alterations in the biochemical profile and impaired reproduction performance in metritic cows.

Evaluation of biochemical profile of dairy cows with metabolic diseases in tropical conditions

The aims of this study were to characterize the biochemical profile, the reproductive performance and to identify potential predictive biomarkers of disease state of dairy cows with hyperketonemia, lipomobilization and hypocalcemia raised in tropical conditions in southeastern Brazil. Dairy cows (n = 50) were divided into a group of healthy cows (n = 14), cows with lipomobilization (n = 14), cows with hypocalcemia (n = 11), and a group of cows with hyperketonemia (n = 11). Evaluation of body condition score (BCS), body weight (BW) and blood samples was performed on 21, 14, 7, 4 and 2 days before calving, parturition, 1, 7, 14, 21, 30, 45 and 60 days post-partum and milk production was recorded on days 7, 14, 21, 30, 45 and 60 after parturition. Blood samples were assayed for aspartate aminotransferase (AST), gamma-glutammyltransferase (GGT), albumin, total protein, globulin, fibrinogen, total cholesterol, triglyceride, urea and creatinine concentrations. The biochemical profile, BCS, BW, milk production and reproductive performance differed (p < .05) among the groups. Our findings indicate changes in the biochemical profile of dairy cows with metabolic diseases and impaired production and fertility of dairy cows in this group. Variable importance in projection plots demonstrated that cholesterol, urea, total protein, albumin and fibrinogen in the serum were the strongest discriminators between cows with hypocalcemia and healthy cows; and AST, cholesterol, urea and triglycerides for cows with hyperketonemia and healthy cows; and cholesterol, urea, triglycerides, total protein and fibrinogen for lipomobilization and healthy cows, which might be useful as predictive biomarkers of the disease state.

Influence of peripartum on the erythrogram of Holstein dairy cows

BACKGROUND

Peripartum is a challenging phase for the health of cows.

OBJECTIVES

This study analysed the haematological profile of Holstein cows during peripartum.

METHOD

Blood samples were collected on days 18, 12, 8, 5 and 2 before calving, at parturition, and on days 1, 7, 14, 21, 30, 45 and 60 postpartum. Analyses of red blood cell (RBC) count, haemoglobin concentration, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration and RBC distribution width were performed; body condition score (BCS) and milk yield were evaluated.

RESULTS

Red blood cell (the highest value was 6.10 × 1012/L at parturition and the lowest recorded value was 5.03 × 1012/L 21 days after parturition), haemoglobin and haematocrit (the highest values were 10.48 g/dL and 33.47% at parturition, respectively and the lowest values were 8.28 g/dL and 26.13% on day 30 after parturition, respectively); BCS (the highest and the lowest values were 3.50 points and 2.73 points on days 18 before parturition and 45 after parturition, respectively) and milk production (the lowest and the highest values were 21.48 L and 27.02 L on days 7 and 45 after parturition, respectively) were significantly different (p 0.05) during the peripartum period. Of the total cows (n = 48), 41.7% had RBC, haemoglobin and haematocrit below the reference intervals during at least one collection point during the postpartum period.

CONCLUSION

This study demonstrated that dairy cows included in this investigation suffered alterations in select haematological variables during the postpartum period.