Predicting the risk of retained fetal membranes and metritis in dairy cows according to prepartum hemogram and immune and metabolic status

Effects of assisted calving and retained fetal membranes on milk production in the smallholder farming system

The impact of assisted calving, retained fetal membranes (RFM) and calf sex on milk production in small-scale dairy systems remains unknown. This study evaluated their impact on early lactation milk production and standardized 305-day yield (305MY) using 279 lactation records from 23 farms over 18 months. Variables analyzed included assisted calving, RFM, calf sex, and lactation number, with milk production at 30 days and 305MY as response variables. General Linear Models were used for statistical analysis, with significance at P < 0.05, and trends at P < 0.1. Lactation number significantly affected early lactation milk production (P = 0.023), with RFM showing a trend toward significance (P = 0.078). Cows without RFM produced 21.8 ± 0.8 kg/day, while those with RFM produced 18.6 ± 1.7 kg/day. Assisted calving significantly affected 305MY (P < 0.05), with cows not requiring assistance having higher yields compared to those needing assistance. Interactions between assisted calving and lactation number (P = 0.099), as well as RFM and calf sex (P = 0.060), approached significance. In cows that did not require assisted calving, no significant differences in 305MY were found based on lactation number (P ≥ 0.05). However, in cows that required assisted calving, significant differences in 305MY (P < 0.05) were observed between first and third or higher lactations, with second-lactation cows having average values. Additionally, cows without RFM that gave birth to female calves had higher 305MY compared to cows with RFM or those that gave birth to male calves with RFM or without RFM. In conclusion, RFM reduces early lactation milk production by approximately 3.2 kg/day, and assisted calving impacts 305MY by about 1,069 kg/lactation.

Risk factors for subclinical endometritis and its effect on reproductive performance in small-scale dairy farms

The study aimed to evaluate the effect of subclinical endometritis (SCE) on reproductive performance and identify risk factors for this pathology in small-scale dairies. In four small-scale dairies, 608 lactations were monitored for health issues, nutritional status, and reproductive events, and SCE was diagnosed based on endometrial polymorphonuclear counting (PMN%) at 30±5 (SCE30) and 60±5 (SCE60) days postpartum. The threshold for diagnosis was established according to the quartile distribution of PMN%; 4 % and 2 % for SCE30 and SCE60. Conception rate at first service (CRFS), number of services per conception (SC), and days open (DO) were analyzed for SCE effect through Chi-square or ANOVA. Events of interest were considered in each lactation to perform a risk factor analysis using univariate logistic regression and multiple logistic regression model building. The population attributable fraction was calculated to identify the most important risk factors. Considering both sampling periods, 40.5 % of the cows were positive for SCE. SCE30-positive cows had lower CRFS (38.9 vs 53.7 %), required 0.4 more SC, and had 20.2 more DO than SCE30-negative cows (P ≤ 0.001). SCE60-positive cows had 16 more DO than SCE60-negative cows (P ≤ 0.01). The most important risk factors for SCE30 were retained fetal membranes (RFM) and uterine diseases, while calving season, RFM, and SCE30 status were the risk factors for SCE60. SCE could represent a major problem in small-scale dairies due to its prevalence and negative effect on reproductive performance. Furthermore, there are identifiable risk factors for SCE under these production conditions, which should be considered when designing prevention strategies.

Discrepancies of bovine haptoglobin concentrations between serum and plasma using two different anticoagulants and a colorimetric assay based on peroxidase activity

BACKGROUND

Haptoglobin (Hp) is an emerging diagnostic marker in cattle, and knowledge of suitable sample types and measurement methods is important.

OBJECTIVES

The aims of this study were to compare the results of a colorimetric assay (CA) and an ELISA for bovine Hp using serum, EDTA plasma, and lithium-heparinized (LH) plasma, respectively, and to assess the diagnostic potential for puerperal metritis.

METHODS

In experiment 1, Hp was measured in pooled aliquots of serum (n = 10), EDTA plasma (n = 10), and LH plasma (n = 10) of 100 healthy fresh lactating dairy cows from 10 farms using both the CA and the ELISA. In experiment 2, five healthy and five cows with acute puerperal metritis were sampled, and Hp was determined using both assays for all three sample types. In experiment 3, aliquots of serum and LH plasma from cows in different lactation stages were transferred into plain, EDTA-coated, and LH-coated tubes and mixed before colorimetric analyses. Distilled water was also placed into each tube type and treated similarly.

RESULTS

Plasma samples measured with the CA showed on average 2.3 (EDTA) and 2.5 (LH) times higher Hp concentrations compared with serum, whereas no differences were seen with the ELISA results between sample types. Based on a clinical cut-off value, both methods differentiated sick from healthy cows. Haptoglobin measurements with the ELISA were less precise compared with CA measurements due to high dilutions. No influence of the anticoagulants on the CA was observed.

CONCLUSIONS

Due to measurement discrepancies between serum and plasma, CAs for bovine Hp based on peroxidase activity should be performed with serum, or specific reference ranges for plasma samples should be established. In this study, CA results obtained with LH plasma were more precise than results obtained with EDTA plasma. Both the CA and the ELISA are suitable diagnostic tools for the diagnosis of puerperal metritis, but CA measurements were more precise in this study.

Association between prepartum vaginal temperature changes and placenta expulsion time in Holstein dairy cattle

Retained placenta (RP) adversely affects postpartum productivity and reproduction in dairy cattle. Thus, methods to predict the occurrence of RP before calving would be desirable. Herein, we assessed whether vaginal temperature measurements (which have already been applied to detect calving) could be used to predict the occurrence of RP in cattle. A vaginal temperature recording device was inserted into the vagina of 49 pregnant Holstein-Friesian heifers (n = 16) and cows (n = 33); this device recorded the vaginal temperature every 5 min until the device dropped out at calving. Serum was collected 10 days before the expected calving date. The time points of calving and placental expulsion were identified via video recordings. We further calculated calving duration (temperature decrease to calving) and placenta expulsion time (PE time = calving to placenta expulsion). The PE times were divided into four categories (0-4 h, 4-8 h, 8-12 h, and RP at >12 h), while subsequent analysis revealed that an extension of the PE time dependent on the shortening of the calving duration (P < 0.05). The vaginal temperature patterns also differed in a PE time-dependent manner, and cows with RP did not show any re-elevation of vaginal temperature. Serum analyses indicated an energy deficiency in RP cattle. These results suggest that RP may be detected early as a specific change in the vaginal temperature associated with reproductive hormone secretion.

Predictive models for metritis cure using farm-collected data, metabolic and inflammation biomarkers, and hemogram variables measured at diagnosis

Our objective was to evaluate the accuracy of predictive models for metritis spontaneous cure (SC) and cure among ceftiofur-treated cows using farm-collected data only, and with the addition of hemogram variables and circulating concentration of metabolites, minerals, and biomarkers (BM) of inflammation measured at time of diagnosis. Data related to parity, calving-related issues, BCS, rectal temperature, and DIM at metritis diagnosis were collected from a randomized clinical trial that included 422 metritic cows from 4 herds in Texas, California, and Florida. Metritis was defined as the presence of red-brownish, watery, and fetid vaginal discharge, and cure was defined as the absence of metritis 14 d after initial diagnosis. Cows were randomly allocated to receive systemic ceftiofur therapy (2 subcutaneous doses of 6.6 mg/kg of ceftiofur crystalline-free acid on the day of diagnosis and 3 d later; CEF) or to remain untreated (control). At enrollment (day of metritis diagnosis), blood samples were collected and submitted to complete blood count (CBC) and processed for the measurement of 13 minerals and BM of metabolism and inflammation. Univariable analysis to evaluate the association of farm-collected data and blood-assessed variables with metritis cure were performed, and variables with P ≤ 0.20 were offered to multivariable logistic regression models and retained if P ≤ 0.15. The areas under the curve for models predicting SC using farm data only and farm + BM were 0.70 and 0.76, respectively. Complete blood count variables were not retained in the models for SC. For models predicting cure among CEF cows, the area under the curve was 0.75, 0.77, 0.80, and 0.80 for models using farm data only, farm + CBC, farm + BM, and farm + CBC + BM, respectively. Predictive models of metritis cure had fair accuracy, with SC models being less accurate than models predictive of cure among CEF cows. Additionally, adding BM variables marginally improved the accuracy of models using farm collected data, and CBC data did not improve the accuracy of predictive models.

Efficacy of an herbal formula Guixiong Yimu San in preventing retained placenta and improving reproductive performance in cows

Retained placenta is a common health issue, and appropriate prevention strategies are effective in postpartum health management. This study aimed to evaluate whether early intervention using GYS can prevent retained placenta and puerperal metritis, as well as enhance reproductive outcomes in cows. Each bovine in the GYS group (n = 591) received a single prophylactic dose of GYS (0.5 g/kg body weight) orally within 2 h after parturition, while those in the control group (n = 598) received no intervention. GYS treatment was associated with a decreased incidence of retained placenta (4.6% vs. 12.0%, P < 0.01, OR = 0.335), a lower puerperal metritis risk (8.8% vs. 20.1%, P < 0.01, OR = 0.369), and a reduced need for additional therapeutic antibiotics (11.2% vs. 26.1%, P < 0.01, OR = 0.342). We observed increases in the first service conception rate (59.7% vs. 49.1%, P < 0.01) and conception rate within 305 days postpartum (93.2% vs. 85.5%, P < 0.01) in the GYS group than in the control group. A significant decrease was observed in the number of services per conception (1.8 ± 1.1 vs. 2.1 ± 1.4, P < 0.01) and the calving-to-conception interval (83.6 ± 39.6 vs. 96.6 ± 52.5 days, P < 0.01) between the two groups. Additionally, GYS treatment increased milk yield on days 7, 14, and 28 postpartum without affecting milk fat, milk protein, somatic cell count (SCC), or milk urea nitrogen (MUN) on days 7 and 28 postpartum. Accordingly, the GYS was effective and safe in preventing retained placenta and to improve reproductive performance in cows. Therefore, it could be a prophylactic intervention for superior postpartum fertility in cows.

Profiling the alterations of serum proteome in dairy cows with retained placenta using high-throughput tandem mass tags quantitative approach

BACKGROUND

Retained placenta (RP), a quite common disorder in dairy cows, shows a high negative impact on their health status and milk production.

AIM

To investigate the difference in the serum proteome between the cows with RP and the physiologic puerperium (PP).

MATERIAL & METHODS

Analysis of serum samples from nine cows with RP and six with PP using high-resolution liquid chromatography-tandem mass spectrometry approach. The proteins differing in the relative abundance between the PP and RP groups were classified using the Protein Analysis Through Evolutionary Relationship tool. For the pathway enrichment analysis, the REACTOME tool, with the human genome as the background, was employed. The criterion for significance was the false discovery rate corrected P-value less than 0.05.

RESULTS

In total 651 proteins were identified with altered relative abundance of ten proteins. Among them, seven had higher, and three showed lower relative abundance in RP than in the PP group. The differently abundant proteins participated in 15 pathways: six related to hemostasis, three involved in lipoprotein metabolism, and the remaining ones associated with for instance redox homeostasis, post-translational modification, and scavenging. Finally, the validation of the proteomic results showed that haptoglobin and lipopolysaccharide-binding protein levels reliably differentiated between the RP and PP groups.

CONCLUSION

The pattern of serum proteome alterations in the cows with RP mirrored several interplaying mechanisms underlying the systematic response to the presence of RP, therefore representing a source to mine for predictive or prognostic biomarkers.

Serum haptoglobin concentration and liver enzyme activity as indicators of systemic inflammatory response syndrome and survival of sick calves

Background

Increased concentration of haptoglobin (Hp) in serum is associated with survival of critically ill humans and horses. High serum activity of liver‐derived enzyme is associated with sepsis in children and foals.

Hypothesis/Objectives

Investigate whether admission serum Hp and glutamic dehydrogenase (GLDH) are associated with systemic inflammatory response syndrome (SIRS) and survival of sick calves.

Animals

One hundred two calves.

Methods

Retrospective cross‐sectional study. Electronic medical records from all calves <30 days of age admitted to a teaching hospital for 8 years were reviewed. The signalment, clinicopathological findings, the presence of SIRS, final diagnosis, hospitalization time and outcome were recorded. A Cox proportional hazard ratio (HzR) were calculated to assess the association between clinicopathological variables and survival to discharge.

Results

Serum Hp concentrations were similar between SIRS (0.29 g/L; range, 0.05‐3.6) and non‐SIRS calves (0.22 g/L; range, 0‐4.2; P = .62). GLDH activity was similar between SIRS (12 U/L; range, 1‐1025) and non‐SIRS calves (9 U/L; range, 2‐137; P = .2). Absent suckle reflex (HzR: 6.44, 95% CI: 1.44‐28.86), heart rate (HR) < 100 beats per minute (bpm; HzR: 12.2; 95% CI: 2.54‐58.62), HR > 140 bpm (HzR: 3.59, 95% CI: 1.05‐12.33), neutrophil count <1.7 × 10⁹/L (HzR: 7.36; 95% CI: 2.03‐26.66) and increased gamma‐glutamyl transferase activity (every 50‐unit, HzR: 1.12; 95% CI: 1.03‐1.21) were predictive of nonsurvival.

Conclusions and Clinical Importance

The use of Hp and GLDH for prediction of survival in sick calves cannot be recommended at this time.