Risk factors for metritis in Danish dairy cows

Testing the Induction of Metritis in Healthy Postpartum Primiparous Cows Challenged with a Cocktail of Bacteria

Metritis is a postpartum uterine disease with greater incidence in primiparous than in multiparous cows. In primiparous cows, the impact on production and health is lessened, presumably due to a superior immune response. Here, we tested whether an in vivo model of clinical metritis induction developed for postpartum multiparous Holstein cows would produce similar results in primiparous cows. Thirty-six cows were randomly assigned to one of three groups and received intrauterine infusion within 24 h of parturition. The controls were infused with sterile saline; the low-dose group received a bacterial cocktail containing 103 cfu of Escherichia coli, Trueperella pyogenes, and Fusobacterium necrophorum; and the high-dose group were infused with 106 cfu of the same cocktail. Production, health traits, and the vaginal discharge culture were assessed daily, from enrollment until 14 d in milk. Clinical metritis occurred in 64% of high-dose cows, 33% of the controls, and 42% of low-dose cows, with no significant difference of incidence between groups. However, when accounting by time, high-dose cows had a 2.7 times greater hazard of metritis compared with the controls. The bacterial challenge affected milk production and dry matter intake tended to decrease. In the high-dose group, a greater growth of F. necrophorum in the selective medium was also observed, suggesting an association with metritis. Therefore, this study suggests intrauterine inoculation with 106 cfu of this bacterial cocktail elicits physical and clinical outcomes consistent with clinical metritis.

Risk factors for ultrasound-diagnosed endometritis and its impact on fertility in Scottish dairy cattle herds

BACKGROUND

The aim of this study was to investigate the risk factors for and the impact of ultrasound-diagnosed endometritis (UDE) on lactating dairy cows' reproductive performance.

METHODS

Data were analysed from 1123 Holstein and Holstein-Friesian cows from two Scottish dairy farms. A reproductive ultrasound examination was conducted on two occasions, at 43 ± 3 and 50 ± 3 days in milk (DIM), to screen for hyperechoic fluid in the uterus. Statistical analyses were performed using multivariable logistic regression modelling and Cox proportional hazards models.

RESULTS

The overall incidence of UDE was 8.8% (99/1123). Risk factors for UDE included calving during autumn/winter seasons, increased parity and the presence of two or more diseases in the first 50 ± 3 days postpartum. The presence of UDE was associated with a reduced odds of pregnancy after all artificial inseminations up to 150 DIM.

LIMITATIONS

The retrospective design of this study led to some inherent limitations with the quality and quantity of data collected.

CONCLUSIONS

The findings of this study indicate which risk factors should be monitored in postpartum dairy cows to limit the impact of UDE on future reproductive performance.

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

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

Financial losses related to placental retention in dairy herds in Turkey

ABSTRACT This study aimed to calculate the financial losses related to placental retention (PR) in dairy cattle in Turkey taking into consideration the previous study results in three different geographical regions and 87 herds of Turkey. The mean prevalence of PR in dairy herds was assumed to be 5.6% (4.1-6.7%). Direct (milk losses, treatment, and involuntary culling) and indirect losses (extended calving interval and extra insemination) were calculated. In the financial analysis, direct and indirect losses were calculated according to the current prices of 2022. As a result, the financial losses per infected dairy cattle were estimated at $ 249.7 (624 Lt milk eq.). A total of 67.7% ($173) of these resulted from direct losses, and the remainder 32.3% ($82.5), were indirect losses. PR was responsible for a total of $92 million (ranged from $67-110 million) losses, which equates to 1.2% (0.8-1.14%) of the annual milk production in Turkey. In conclusion, magnitude of PR-related losses will provide evidence-based decision support to the farmers and policymakers when determining the priorities for disease mitigation and control strategies.

The Welfare of Dairy Cows in Pasture, Free Stall, and Compost Barn Management Systems in a Brazilian Subtropical Region

The effect of milk production systems on the welfare of dairy cows has been studied worldwide, but studies that compare pasture-based, compost barn, and free stall systems, according to animal welfare, are more scarce. In this work, the welfare of 51 dairy herds, including 17 from each management system, was investigated through the application of the Welfare Quality® protocol. Descriptive statistics and the Kruskal-Wallis non-parametric method were used to analyze variables. In the present work, the welfare of the evaluated herds was significantly better in the pasture-based system than in the confinement systems. However, the pasture-based system presented weaknesses in providing water resources. The compost barn had fewer animal welfare critical points than the free stall system, as well as it was better than the free stall in measures related to comfort and health. The free stall did not present better scores than the other systems. It is concluded that the welfare of dairy cows is affected by the rearing system, with better scores, in most measures, in the pasture-based system, followed by the compost barn and, finally, the free stall.

Prevention of retained fetal membranes and improvement in subsequent fertility with oxytocin administration in cows with assisted calving

In dairy cows, the efficacy of oxytocin treatment for preventing retained fetal membranes (RFM) is controversial. The physiological condition of cows associated with the calving process may affect the action of oxytocin. This study aimed to elucidate the difference in the efficacy of exogenous oxytocin treatment immediately after calving among cows that received various obstetric interventions. The calving ease was recorded using a score of 1-5, and assisted birth was defined as a score of 2 or more. Cows that required calving assistance (assisted, n = 28) due to delayed calving progression had a prolonged time from calving to expulsion of the fetal membrane (P < 0.01), and impaired reproductive performance compared to cows that did not receive calving assistance (unassisted, n = 78). The effect of oxytocin treatment was determined using cows that did not expel their fetal membrane within 3 h after calving. Cows were randomly divided into the control (unassisted, n = 41; assisted, n = 22) or oxytocin group (unassisted, n = 33; assisted, n = 10). Oxytocin (50 IU) was administered intramuscularly to the cows in the oxytocin group between 3 and 6 h after calving, while no treatment was administered in the control group. In cows with assisted birth, oxytocin administration accelerated placental expulsion (P < 0.05) and improved several reproductive parameters, such as the number of services until conception (P < 0.05) and the calving to conception intervals (P < 0.05) compared to the control group. On the other hand, oxytocin administration slightly accelerated placental expulsion (P < 0.05), but failed to improve fertility in cows with unassisted birth. The results indicate that the action of oxytocin varies depending on the calving situation of the cows. Oxytocin administration during the early postpartum period could prevent RFM and improve the decline in reproductive performance associated with calving assistance.

Prepartum factors associated with postpartum diseases in pasture-based dairy cows

This cross-sectional observational study aimed to identify prepartum management, environmental, and animal factors associated with clinical -lameness, metritis, mastitis- and subclinical -calcium imbalance, magnesium imbalance- diseases in pasture-based dairy cows. A total of 565 cows from 25 commercial dairy farms in southern Chile were enrolled over four months. Data on prepartum management and environmental conditions were obtained through a survey and inspections of prepartum paddocks. Cows were evaluated two times. In the first evaluation, between 30 to 3 days before calving, cows were assessed for lameness, body condition score, and blood samples were collected to measure nonesterified fatty acid (NEFA), calcium (Ca), and magnesium (Mg). In the second evaluation, between 3 to 21 DIM, cows were assessed for metritis, lameness, and blood samples were collected and analyzed for total Ca and Mg concentration. Cows were considered as having Ca imbalance if Ca < 2.0 mmol/L, and Mg imbalance if Mg < 0.65 mmol/L. Postpartum clinical mastitis was diagnosed based on the foremilk's daily condition and udder assessed by the milker at each milking during the postpartum transition period. Multivariable logistic regression models, controlling for the farm as a random effect, were built to identify prepartum factors for each postpartum disease. The odds of postpartum lameness were higher for cows that were lame during the prepartum period, had elevated prepartum NEFA concentrations, had greater parity, and for cows that were kept in paddocks with no grass cover. The odds of metritis were higher in cows with lower parity, with increased prepartum NEFA, in cows that had dystocia, and farms with predominantly Holstein breed, and that did not have calving records. The odds of clinical mastitis were higher for cows lame during the prepartum period. The odds of Ca imbalance were higher in cows with a long dry period, dystocic calving, and in farms without prepartum anionic salts supplementation. The odds of Mg imbalance were higher in cows with lower prepartum Mg concentrations, higher prepartum Ca concentration, and higher parity. Our findings indicate that farmers could benefit from refining these areas to improve their cows' health and welfare.

Invited review: The welfare of dairy cattle housed in tiestalls compared to less-restrictive housing types: A systematic review

Many dairy cattle worldwide are housed in tiestalls, meaning that they are tethered by the neck to individual stalls. On some farms, tied cattle are permitted seasonal access to pasture, but otherwise their movements are restricted compared with cows housed in freestall barns or other loose housing systems. The aim of this systematic review is to summarize the scientific literature pertaining the welfare of tied dairy cattle through comparison with less-restrictive housing systems. Articles identified by PubMed and Web of Science underwent a 5-phase screening process, resulting in the inclusion of 102 papers. These papers addressed measures of welfare related to affective state, natural behavior, and health (with the lattermost category subdivided into hoof and leg disorders, lameness, mastitis, transition disease, and other diseases or conditions). Health was the most researched topic (discussed in 86% of articles); only 19% and 14% of studies addressed natural behavior and affective state, respectively. Our review highlights different health benefits for tethered and loose cattle. For example, tied cattle experience reduced prevalence of white line disease and digital dermatitis, whereas loose cattle experience fewer leg lesions and injuries. The prevalence of mastitis, transition diseases, and other conditions did not differ consistently across housing types. We found that the expression of certain natural behaviors, particularly those associated with lying down (e.g., time spent kneeling, unfulfilled intentions to lie down), were impaired in tiestalls. Articles addressing affective state found benefits to loose housing, but these studies focused almost exclusively on (1) physiological measurements and (2) cow comfort, a concept that lacks a consistent operational definition across studies. We call for future research into the affective state of tied cattle that extends beyond these explorations and employs more sophisticated methodologies.

Incidence, clinical patterns, and risk factors of postpartum uterine diseases in dairy cows from high-altitude tropical herds

The cow's uterus sustains bacterial contamination and active inflammation after calving as part of the normal physiological process of uterine involution. Although the definition, incidence, and risk factors for postpartum uterine diseases (PUD) have been documented in annual calving systems with high-producing cows on total mixed ration, the literature contains little information for other production systems. The objective of this study was to quantify the incidence risk and factors associated with metritis, clinical endometritis, and cytological endometritis in high-altitude tropical dairy herds in a pasture-based system. A total of 248 cows from 5 commercial dairy herds in northern Antioquia, Colombia, were enrolled in this prospective observational longitudinal cohort study. Data collection and PUD diagnosis were performed at d 0, 3, 10, 17, 24, 31, 38, 45, and 52 (±1) after parturition. Between 60 and 70 d, cows were systematically enrolled in a synchronization protocol, and herds were visited monthly for pregnancy diagnosis until 180 ±15 d. The multivariable logistic regression model of variables associated with PUD occurrence included (a) parity, season of calving, transition diet, and body condition score at calving; (b) blood calcium, phosphorus, and magnesium concentrations, and milk urea nitrogen, β-hydroxybutyrate and fat-to-protein ratio; and (c) dystocia, retained placenta, and delayed uterine involution. The incidences of puerperal metritis, clinical metritis (MET), clinical endometritis (CE), and cytological endometritis (CYTO) were 2.8, 25, 29, and 26%, respectively. Retained placenta and dystocia were associated with MET, and MET was associated with CE. Low blood calcium concentration at calving was associated with CYTO. Overall, 51.2% of the cows suffered at least 1 category of PUD during the first 60 d postpartum (DPP). However, cows also suffered from different consecutive clinical events of PUD (MET, CE, and CYTO) during the follow-up period (0 to 180 ±15 DPP). These events could be grouped into 4 types (which were referred to as "clinical patterns") based on interactions between MET, CE, and CYTO.

Clinical disease incidence during early lactation, risk factors and association with fertility and culling in grazing dairy cows in Uruguay

This paper aims to describe clinical disease incidence in early lactation and explore its association with fertility and culling in 13 commercial grazing dairy herds in Uruguay. Seven farms with less than 250 dairy cows considered small herds (SH) with a herd size average ± (SD) of 144 ± (56) cows and six farms with more than 500 cows considered large herds (LH) with a herd size average ± (SD) of 830 ± (239) cows were selected. Herd managers recorded health events during the first 90 days in milk in 5375 Holstein dairy cows [24.5% (n=1316) of them were primiparous cows, (PP)] during one year. Overall, 36.5% (n=1959) of the cows had at least one clinical health event between 1-90 days in milk. The cumulative incidences were 2.2% for twin birth and 4.9% for stillbirth. Cumulative incidence was 4.4% for retained placenta-metritis (RP-metritis), 27.6% for clinical mastitis and 5.0% for lameness. Our data showed that parity and herd size were risk factors for postpartum disease in grazing dairy herds. In PP cows, stillbirth incidence was higher than in multiparous (MP) cows (PP=6.9 ± 3.4, SD vs. MP=4.3 ± 2.6, SD), while in MP cows twin births (MP=2.7 ± 1.7, SD vs. PP=0.7 ± 2.7, SD), RP-metritis (MP=4.6 ± 3.9, SD vs. PP=3.8 ± 3.7, SD) and mastitis incidence (MP=30.9 ± 11.4, SD vs. PP=17.2 ± 13.9, SD) was higher. Clinical mastitis (LH=29.4 ± 9.6, SD vs. SH=19.1 ± 11.3, SD) and lameness incidence (LH=5.6 ± 1.9, SD vs. SH=2.3 ± 2.1, SD) was higher in large herds than in small herds. RP-metritis was increased by stillbirth (OR=4.4, 95 % CI=2.9-6.5) and twin birth (OR=2.8, 95 % CI=1.5-5.1). Diseases had a negative impact on time to first service and pregnancy rate and increased culling hazard rate. Disease incidence in early lactation was high and showed a wide variation among herds (10.4%-48.7%), which highlights the relevance of a herd health program prioritizing the early lactation disease control.

Predicting Disease in Transition Dairy Cattle Based on Behaviors Measured Before Calving

Simple Summary

Dairy cattle often become ill after calving. We developed models designed to predict which cows are likely to become ill based upon measures of the cows’ feeding and competitive behaviors before calving. Our models had high sensitivity (73–71%), specificity (80–84%), positive predictive values (73–77%), and negative predictive values (80–80%) for both cows that had previously calved and for those calving for the first time. We conclude that behaviors at the feed bunk before calving can predict cows at risk of becoming sick in the weeks after calving.

Abstract

Dairy cattle are particularly susceptible to metritis, hyperketonemia (HYK), and mastitis in the weeks after calving. These high-prevalence transition diseases adversely affect animal welfare, milk production, and profitability. Our aim was to use prepartum behavior to predict which cows have an increased risk of developing these conditions after calving. The behavior of 213 multiparous and 105 primiparous Holsteins was recorded for approximately three weeks before calving by an electronic feeding system. Cows were also monitored for signs of metritis, HYK, and mastitis in the weeks after calving. The data were split using a stratified random method: we used 70% of our data (hereafter referred to as the “training” dataset) to develop the model and the remaining 30% of data (i.e., the “test” dataset) to assess the model’s predictive ability. Separate models were developed for primiparous and multiparous animals. The area under the receiver operating characteristic (ROC) curve using the test dataset for multiparous cows was 0.83, sensitivity and specificity were 73% and 80%, positive predictive value (PPV) was 73%, and negative predictive value (NPV) was 80%. The area under the ROC curve using the test dataset for primiparous cows was 0.86, sensitivity and specificity were 71% and 84%, PPV was 77%, and NPV was 80%. We conclude that prepartum behavior can be used to predict cows at risk of metritis, HYK, and mastitis after calving.

Hormonal and metabolic profiles related to placental retention with emphasis on oxidative stress and serotonin receptors in pluriparous buffaloes

This study was designed to investigate the hormonal and metabolic factors associated with placental retention in buffaloes with respect to the roles of oxidative stress biomarkers and serotonin receptors. Blood samples were collected at weeks 3, 2 and 1 pre-partum and at calving from 37 buffaloes; thirty normally dropped their placentae (Non-RFM group) and 7 dropped their placentae after 12 hr post-calving (RFM group). Serum progesterone (P₄ ), oestradiol, cortisol, non-esterified fatty acids (NEFA), beta-hydroxybutyric acid (BHBA), antioxidant/oxidant biomarkers and mineral concentrations were assessed. Histopathology and histochemistry were implemented to detect collagen in foetal placental tissues. Immunohistochemistry for serotonin receptors in placental tissues was performed. Significant elevations in P₄ , cortisol, NEFA, BHBA and oxidative biomarkers concentrations were observed in the RFM group. However, oestradiol, antioxidants and mineral concentrations were significantly lower in RFM buffaloes than Non-RFM group. Histopathological examination revealed degenerative changes and necrosis in retained placental tissue compared with that in normal placental tissues. Serotonin receptors were significantly expressed with collagen condensation in retained placental tissues. Furthermore, inferior reproductive performance was pronounced in the retained group. In conclusion, retained foetal membranes in buffaloes were associated with hormonal imbalance, metabolic perturbation, oxidative stress, serotonin receptor upregulation and markedly reduced fertility indices.

Feeding behavior and agonistic interactions at the feed bunk are associated with hyperketonemia and metritis diagnosis in dairy cattle

Hyperketonemia and metritis are common in the weeks after calving. This study tested if feeding and agonistic behaviors before calving were associated with the development of hyperketonemia (HYK) and metritis after calving. Holstein cows on 5 commercial farms were monitored for HYK (as identified using a cow-side β-hydroxybutyrate test) and metritis (using visual and olfactory assessment of vaginal discharge); both tests were conducted twice a week for 2 wk. Based on this assessment, we selected a balanced sample of cows that remained healthy (no signs of illness; n = 20), cows diagnosed with either HYK (n = 20) or metritis (n = 20), and cows with both HYK and metritis (n = 20). Video recordings from the 8 wk before calving (scored every 2 wk for 90 min immediately after fresh feed delivery) were used to evaluate feeding behavior and competition at the feed bunk. Feeding behavior before calving was associated with postpartum diagnosis of HYK and metritis. Specifically, cows that spent less time eating had higher odds of HYK and metritis. Odds of remaining healthy (compared with becoming sick with at least 1 condition) increased by 1.3 times for every additional 15 min spent eating. Additionally, cows that were involved in fewer agonistic interactions prepartum were more likely to be diagnosed with both conditions during the postpartum period. Odds of remaining healthy (compared with becoming sick with at least one condition) increased by 1.9 times for every 6 additional interactions. We conclude that prepartum feeding and agonistic behaviors can be used to identify animals at risk of HYK and metritis postpartum.

Pilot study assessing the possible benefits of a higher level of implementation of biosecurity measures on farm productivity and health status in Belgian cattle farms

Over the last few years, the interest of decision-makers and control agencies in biosecurity (BS), aiming at preventing and controlling the introduction and spread of infectious diseases, has considerably increased. Nevertheless, previous studies highlighted a low implementation level of biosecurity measures (BSM), especially in cattle farms; different reasons were identified such as perceived costs, utility, importance, increased workload and lack of knowledge. In order to convince cattle farmers to adopt BSM, it is necessary to gather more information and evidence on their cost-effectiveness and their importance or utility in terms of disease prevention and control. The objectives of this study were to determine whether the farm or farmers' profile correlated with the implementation level of BSM and if there was a positive correlation between the BSM implementation and the farm production and health parameters. Data were collected through face-to-face interviews conducted in 100 Belgian farms as part of a stratified and randomized survey. The Regional Animal Health Services provided the farm health status and production data. A general BS score and five sub-scores related to the five BS compartments (bio-exclusion, bio-compartmentation, bio-containment, bio-prevention and bio-preservation) were calculated for each farm based on the implementation level of different BSM grouped in 16 domains. The study highlighted a significant and negative correlation between the mortality rates in adult cattle (over 24 months of age) and young calves (aged 0-7 days) and different BS compartment scores. The study also demonstrated that the farms having a higher general BS score were indeed more likely to have a BVD-free status. These evidence-based findings are encouraging as they demonstrate the benefits of implementing BSM and could promote their adoption by farmers.

Cow-level risk factors for reproductive tract disease diagnosed by 2 methods in pasture-grazed dairy cattle in Ireland

The cow-side diagnosis of reproductive tract disease (RTD) involves identifying the presence of purulent vaginal discharge (PVD) and ultrasonographic endometritis (UE). The objectives of our study were to obtain prevalence estimates for RTD diagnosed by 2 methods (PVD and UE scoring) and to investigate the risk factors for increased probability of RTD if these methods are used in isolation or in combination. Our retrospective observational cohort study tested the hypothesis that RTD assessed by 2 methods would have similar risk factors, and that those would be mainly cow- and calving-related factors. We analyzed data from 5,049 pre-breeding examinations (PBE) from 2,460 spring-calved cows on 8 farms between 2014 and 2018. Cow-related details assessed were days in milk at PBE, breed, lactation number, dry period length, body condition score at calving and PBE, 305-d milk yield, predicted transmitting ability for production and fertility, the presence of a corpus luteum at PBE, and positive diagnosis the previous year. Calving details assessed were type of sire, calf sex, twinning, stillbirth, calving difficulty score, and retained fetal membranes. We conducted statistical analyses using 4 multivariable logistic regression models to identify the risk of RTD diagnosed by (1) PVD in isolation, (2) UE in isolation, (3) the presence of either PVD or UE; and (4) the presence of both PVD and UE. We accounted for herd, cow, and year as random effects in all 4 models. The overall prevalence of RTD in models 1, 2, 3, and 4 were 7.5, 6.7, 11.6, and 2.6%, respectively. Days in milk at PBE, the interaction between days in milk and retained fetal membranes, twinning, and the predicted transmitting ability for calving interval were consistently significant risk factors for positive scores in all 4 models. Considerable calving difficulty [adjusted odds ratio (AOR) = 13.64], Holstein Friesian dam breed (AOR = 2.58), first lactation (AOR = 2.39), and body condition score at PBE (AOR = 1.64) were risk factors for a positive PVD score but not for a positive UE score. Fifth lactation (AOR = 1.69), a beef-sired calf (AOR = 1.46), and the absence of a corpus luteum at PBE (AOR = 1.57) were risk factors for a positive UE score but not for a positive PVD score. These results support the hypothesis that most of the risk factors for PVD and UE are the same but some are distinctly different, implying that in some instances the 2 methods diagnose separate components of the RTD complex.

The Effect of Abnormal Reproductive Tract Discharge on the Calving to Conception Interval of Dairy Cows

Prolonged calving-to-conception interval (CCI) can increase economic loss in cattle. We investigated the effect of post-calving abnormal reproductive tract discharge (ARTD) on CCI in dairy cows and quantified the relationship of ARTD and associated risk factors with CCI. The source population was dairy cows that calved in the study period on three pasture-based, year-round calving farms in the Riverina, NSW, Australia. Farm records and records from veterinarians' visits were analyzed. ARTD was defined as the presence of reproductive tract discharge according to the following classification: per vaginum purulent discharge ≥21 days post-calving or mucopurulent discharge >26 days post-calving. The incidence of ARTD was calculated. A Kaplan-Meier survivor function was used to estimate median time to conception post-calving dependent on the presence or absence of ARTD. Mixed effects Cox-proportional hazard models were used to estimate the direct and indirect effects of ARTD, and other potential risk factors on CCI such as body condition score (BCS), ambient temperature, and milk yield. Model structures were guided by a directed acyclic graph of potential risk factors for ARTD. The incidence of ARTD in lactations was 16% (95% CI 13.8–18.5%) and did not differ significantly between the three farms (P > 0.05). The median CCI was 176 and 118 days for lactations with and without ARTD, respectively (P < 0.01). The rate of pregnancy following calving in cows with ARTD was significantly decreased relative to the rate of pregnancy in cows without (total effect hazard ratio = 0.62, se = 0.18, P = 0.01). High peak milk yield (>32 L) and parity >2 also significantly extended CCI. We did not observe an effect of BCS or ambient temperature on CCI. The incidence of ARTD in the current study was consistent with clinical endometritis (considered a major source of ARTD) reported in other studies. In contrast—and despite regular veterinary assessment and treatment of on the farms in this study—ARTD extended CCI. Evaluation of the economic impact of ARTD on dairy farms in this region is warranted, and methods to identify high risk cows and develop effective interventions are required.

Influence of on-farm measurements for heat stress indicators on dairy cow productivity, female fertility, and health

The aim of the present study was to quantify the effect of heat stress (HS) from different points in time on production, female fertility, and health traits. In this regard, on-farm measurements for temperature and relative humidity were combined into temperature-humidity indexes (THI), and merged with longitudinal cow traits from electronic recording systems. The study included traits from 22,212 Holstein cows kept in 15 large-scale dairy co-operator herds. Trait and meteorological data recording spanned a period between May 2013 and November 2015. Longitudinal production traits considered 191,911 test-day records for protein yield, protein percentage, and milk urea nitrogen (MUN). Female fertility traits were the pregnancies per AI (P/AI) and the number of daily inseminations per herd cow (INS/HCOW). Health traits considered clinical mastitis (MAST), retained placenta, puerperal disorders (PD) from d 0 to 10 postpartum, and the claw disorders digital phlegmona, digital dermatitis (DD), and interdigital hyperplasia from d 0 to 360 postpartum. For all traits, we analyzed the THI influence from the trait-recording day. In addition, we studied the time-lagged THI effect from the previous week. Linear mixed models were applied to estimate THI effects on Gaussian distributed production traits. For binary health and fertility traits, generalized linear mixed models with a logit link function were used. The continuous THI effect was either modeled linear, or via Legendre polynomials of order 4. Regression models for THI were validated via THI class effects (i.e., 5% percentiles for THI). Protein percentage decreased with increasing test-day THI, and with increasing THI from the previous week. Protein yield obviously decreased beyond THI 68 for both THI measurements (test-day THI and THI from previous week). For MUN, the visually identified test-day HS threshold was THI 70. Time-lagged THI effects on MUN were less obvious. For both THI measuring dates, INS/HCOW was highest at THI 57. Beyond THI 57, INS/HCOW substantially decreased. For P/AI, the visually identified HS threshold at the insemination date was THI 65. Temperature-humidity indexes from the previous week had a moderate detrimental effect on P/AI. Incidences for MAST, retained placenta, and PD during d 0 to 10 postpartum increased with increasing average THI from this period. Studying the whole lactation period, incidences for interdigital hyperplasia also increased with increasing THI from the previous week. An opposite THI response was identified for DD: DD decreased with increasing THI. For all health traits, associations between disease incidences and THI were almost linear. Hence, for health traits, no obvious HS thresholds were detected. Especially in early lactation, HS had a detrimental effect on cow productivity and female fertility. The influence of HS on cow health differed, depending on the disease pathogenesis.

Fungal endometritis in bovines

Fungus is well capable of producing reproductive failures in bovines. As fungus is an opportunistic pathogen, there are more chances for fungus to cause infection in the uterus when certain predisposing factors like prolonged intra-uterine antibiotic therapy, persistent endometritis, presence of necrotic foci, immunosuppression, and pneumovagina are available. Various authors have reported the incidence of fungal endometritis in repeat breeder endometritic cows and buffaloes. Uterine culture along with the cytological examination of the uterine secretions considered being best way to diagnose this condition; however, endometrial biopsy can be used to access the efficacy of treatment to invasive yeast. Intra-uterine treatment with antiseptic solutions and Lugol’s iodine had been found effective in bovines..

Characterisation of peripheral blood mononuclear cell populations in periparturient dairy cows that develop metritis

Bacterial contamination of the uterus following calving is ubiquitous in the dairy cow, 40% of cows develop postpartum uterine infection, including metritis. While predisposing factors like twinning and dystocia are associated with metritis, it is unclear why some cows remain healthy following calving and others develop uterine infection, negatively impacting animal health, milk production and economic return. Here, we profiled peripheral blood mononuclear cells of cows before calving and during postpartum metritis. We hypothesized that peripheral blood mononuclear cell function and proportions would be altered during the prepartum period in cows that develop postpartum metritis. Using flow cytometry we observed reduced proportions of peripheral CD3⁺/CD4⁺, CD4⁺/CD62L⁺, FOXP3⁺ and CD21⁺ populations from -10 to 40 days relative to calving associated with metritis, while the proportion of peripheral CD3⁺/CD4⁺ lymphocytes were specifically reduced in the prepartum period before the onset of metritis. Peripheral blood mononuclear cells from cows with metritis had a perturbed capacity to secrete IL-1β or IFNγ in response to in vitro stimulus; cells collected during the prepartum period from cows that would go on to develop metritis failed to increase IL-1β secretion in response to stimulation, while IFNγ secretion was altered at calving and postpartum in cows with metritis compared to healthy herd mates. No effect of metritis was observed in the capacity of cows to mount a humoral immune response to antigen administered on the day of calving. The studies discussed here suggest that while minor changes to the prepartum immune system are observed in cows that develop metritis, changes observed in the postpartum period are more prevalent and likely a consequences of disease and not causative. Future studies to modulate the prepartum immune system may help to limit postpartum metritis.

Cytological endometritis in dairy cows: diagnostic threshold, risk factors, and impact on reproductive performance

We determined the threshold proportion of polymorphonuclear leukocytes (PMNs) for a diagnosis of cytological endometritis (CEM), the risk factors for this condition, and its impact on reproductive performance in dairy cows. Uterine cytology was performed on 407 Holstein cows 4 weeks postpartum to determine the proportions of endometrial cells and PMNs. A receiver operator characteristics curve was used to determine the threshold above which the PMN proportion affected the likelihood of cows conceiving by 200 days postpartum. The optimal threshold was ≥ 14% PMN (sensitivity, 31.3%; specificity, 81.7%; p ＜ 0.05). The farm identity, retained placenta (odds ratio [OR] = 1.87), and septicemic metritis (OR = 3.07) were risk factors for CEM (p ＜ 0.05). Cows with CEM were less likely to resume cyclicity (OR = 0.58) and to conceive by 200 days postpartum (hazard ratio = 0.58). Cows with CEM tended (p ＜ 0.1) to be less likely to become pregnant after their first insemination (OR = 0.65) and to require a greater number of inseminations per conception (2.3 vs. 2.2). In conclusion, a PMN threshold of 14% defined the presence of CEM at 4 weeks postpartum. The farm, retained placenta, and septicemic metritis were risk factors for CEM, which reduces subsequent reproductive performance.

Metabolic predictors of peri-partum diseases and their association with parity in dairy cows

The predictive values of plasma non-esterified fatty acid (NEFA), beta-hydroxybutyrate (BHB), cholesterol, albumin and calcium to predict risk of peripartum diseases in primiparous (PP) and multiparous (MP) Holstein cows was investigated. Besides it was assessed if the health status interacted with parity on body condition score and metabolic profiles during the transition period. Dairy cows (126 PP and 182 MP) from a commercial dairy free stall herd (loose-housing system) were weekly body condition scored and tail bled for metabolites determination from -3 to +4 weeks relative to calving. Peripartum diseases were diagnosed by a single trained veterinarian, while subclinical diseases (ketosis and hypocalcemia) were diagnosed at the laboratory. Cows were classified as healthy cows, cows with one event, or cows with two clinical events following a prospective observational cohort study, with only healthy cows enrolled at the beginning of the study. The largest incidence was for metritis (26.6%) followed by retained placenta (17.2%) and mastitis (15.2%) with no effect of parity, while subclinical hypocalcemia incidence was greater in MP than PP cows (43% vs 9.5%) respectively. In MP cows albumin concentrations were predictive for metritis at week -2 and for retained placenta at weeks -2 and -1, while cholesterol was predictive for mastitis at week -2, -1 and at calving. The interaction between health status and parity affected all metabolites during the transition period. This study showed a different evolution of metabolic profiles in healthy and sick cows during the transition according to parity, pointing out albumin and cholesterol as diseases predictors before calving.

INVITED REVIEW: Farm size and animal welfare

Critics of agricultural intensification have argued that the transition from smaller to larger farms has compromised animal welfare. To critically examine evidence relevant to this claim, we reviewed more than 150 publications that examined the relationship between farm size and at least one animal welfare indicator. Although much of this literature focuses on dairy cattle, we also reference other farmed species where appropriate. We found little evidence of any simple relationship, negative or positive, between farm size and animal welfare. Instead, the evidence suggests that larger farms provide some opportunities to improve animal welfare but may also create welfare risks. For example, larger farms permit more specialized and professional management of animal health but can make it more difficult to accommodate outdoor access that some view as integral to animal welfare. Future research should attempt to specify the underlying casual mechanisms by which statistical associations between farm size and indicators of welfare are believed to occur. We also suggest that policy and advocacy efforts aimed at reversing increases in farm size would be better directed toward improving welfare on farms of all sizes.

Association between Prepartum Feeding Behavior and Periparturient Health Disorders in Dairy Cows

The objective of this study was to investigate the relationship between prepartum feeding behavior, measured as time spent feeding per day, and periparturient health disorders, milk yield, milk composition, and milk somatic cell count in Jersey cows. Pregnant Jersey cows were marked with unique alphanumeric symbols and were moved into a prepartum group 4 weeks prior to their expected calving date. At enrollment, cows with a body condition score <2 or >4 or a locomotion score >3 were not included. Time spent feeding was measured using 10-min video scan sampling for 24-h periods of 2–4 days per week of the study. A total of 925 cows were eligible for analysis. Parity was based on lactation number at the time of enrollment and classified as nulliparous (cows pregnant with their first calf), primiparous (cows pregnant with their second calf), and multiparous (lactation ≥2). Multiparous cows with two or more health disorders spent approximately 10% less time feeding prepartum than cows that did not have any health disorders. Multiparous cows subsequently diagnosed with metritis had a tendency to spend 5% less time feeding prepartum than healthy counterparts. Primiparous cows with retained placenta had a 10% reduction in feeding time compared to healthy primiparous cows. Monitoring time spent feeding prepartum by primiparous and multiparous cows, even on a limited number of days, appeared to be beneficial in predicting cows at risk for periparturient health disorders. Real-time daily feeding behavior monitoring technologies that can be used by dairy farms are now available, which might prove to be even more helpful in identifying cows at risk for periparturient cow health disorders as more data points can be recorded for each cow and compared to her own behavior or that of specific cohorts.

Review: welfare of dairy cows in continuously housed and pasture-based production systems

There is increasing interest in the use of continuous housing systems for dairy cows, with various reasons put forward to advocate such systems. However, the welfare of dairy cows is typically perceived to be better within pasture-based systems, although such judgements are often not scientifically based. The aim of this review was to interrogate the existing scientific literature to compare the welfare, including health, of dairy cows in continuously housed and pasture-based systems. Although summarising existing work, knowledge gaps and directions for future research are also identified. The scope of the review is broad, examining relevant topics under three main headings; health, behaviour and physiology. Regarding health, cows on pasture-based systems had lower levels of lameness, hoof pathologies, hock lesions, mastitis, uterine disease and mortality compared with cows on continuously housed systems. Pasture access also had benefits for dairy cow behaviour, in terms of grazing, improved lying/resting times and lower levels of aggression. Moreover, when given the choice between pasture and indoor housing, cows showed an overall preference for pasture, particularly at night. However, the review highlighted the need for a deeper understanding of cow preference and behaviour. Potential areas for concern within pasture-based systems included physiological indicators of more severe negative energy balance, and in some situations, the potential for compromised welfare with exposure to unpredictable weather conditions. In summary, the results from this review highlight that there remain considerable animal welfare benefits from incorporating pasture access into dairy production systems.

PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM: Uterine infection: linking infection and innate immunity with infertility in the high-producing dairy cow

Uterine contamination with bacteria is ubiquitous in the postpartum dairy cow. Nearly one-half of all postpartum dairy cows develop clinical disease resulting in metritis and endometritis, which cause depressed milk production and infertility. The causative links between uterine infection and infertility include a hostile uterine environment, disrupted endocrine signaling, and perturbations in ovarian function and oocyte development. In this review we consider the various mechanisms linking uterine infection with infertility in the dairy cow, specifically 1) innate immune signaling in the endometrium, 2) alteration in endocrine signaling in response to infectious agents, and 3) impacts of infection on ovarian function, oocyte development, and follicular development. Normal ovarian follicular and oocyte development requires a series of temporally and spatially orchestrated events; however, several of the cellular pathways required for ovarian function are also used during the innate immune response to bacterial pathogens. We propose that activation of cellular pathways during this immune response has a negative impact on ovarian physiology, which is manifest as infertility detected after the clearance of the bacteria. This review highlights how new insights into infection and immunity in cattle are linked to infertility.

The associations between postpartum serum haptoglobin concentration and metabolic status, calving difficulties, retained fetal membranes, and metritis

Measurement of serum haptoglobin (Hapto) concentrations results in only moderate reported specificity and sensitivity for the detection of metritic cows. The objective of this study was to evaluate associations between different variables and haptoglobin concentrations after calving. Parity, periparturient metabolic stress indicated by β-hydroxybutyric acid (BHBA) and nonesterified fatty acids (NEFA), calving difficulties, retained fetal membranes (RFM), and acute puerperal metritis (APM) were evaluated. A total of 443 Holstein Friesian cows were enrolled in this retrospective observational study. Acute puerperal metritis was diagnosed when a cow had fetid, reddish-brown, watery vaginal discharge in combination with rectal temperature ≥39.5°C. The retention of the fetal membranes has been defined as the failure to expel the fetal membranes within 12h after calving. Results of blood samples from 2 and 5 d in milk (DIM) were analyzed for Hapto, BHBA, and NEFA. Primiparous cows had a greater median Hapto concentration than multiparous cows at 5 DIM [primiparous: 2.25g/L, interquartile range (IQR) 1.45-2.50, n=146; multiparous: 1.13g/L, IQR 0.52-2.22, n=302; P<0.05]. Therefore, different Hapto thresholds based on references from literature for all cows (1.4g/L), primiparous cows (2.49g/L), and multiparous cows (1.4g/L) were used for further analysis. Periparturient metabolic stress indicated by elevated BHBA (≥1.2mmol/L) at 5 DIM was associated with elevated Hapto (odds ratio 2.39-2.87) regardless of parity. In contrast, elevated NEFA (≥0.6mmol/L) at 2 DIM was not a risk factor for elevated Hapto. Multiparous cows with assisted calving had a 2.46 times higher risk for elevated Hapto, whereas primiparous cows with assisted calving had no elevated risk for elevated Hapto at 5 DIM. Moreover, multiparous cows with RFM were 5.51 times more likely to have elevated Hapto at 5 DIM than cows without RFM. Acute puerperal metritis within the first 5 DIM was associated with elevated Hapto (odds ratio 2.74-5.01), regardless of parity. We speculate that the association of calving ease, RFM, and periparturient metabolic stress could explain the moderate sensitivity and specificity reported for the detection of metritic cows by measuring Hapto.

Genes and environmental factors that influence disease resistance to microbes in the female reproductive tract of dairy cattle

Microbes commonly infect the female reproductive tract of cattle, causing infertility, abortion and post partum uterine diseases. When organisms reach the uterus, the resistance to disease depends on the balance between the classic triad of the virulence of the microbes, the host defence systems and the environment. The present review considers each aspect of this triad, using postpartum uterine disease as an exemplar for understanding disease resistance. The bacteria that cause postpartum uterine disease are adapted to the endometrium, and their microbial toxins cause tissue damage and inflammation. However, non-specific defence systems counter ascending infections of the female reproductive tract, and inflammatory responses in the endometrium are driven by innate immunity. Disease resistance to bacterial infection involves many genes involved in the maintenance or restoration of tissue homeostasis in the endometrium, including antimicrobial peptides, complement, cytokines, chemokines and Toll-like receptors. The most important environmental factors facilitating the development of postpartum uterine disease are related to trauma of the reproductive tract and to the metabolic stress of lactation in dairy cows. Long-term solutions for uterine disease will include genetic selection for disease resistance and optimising the care of the animal before, during and after parturition.

Dairy cows welfare quality in tie-stall housing system with or without access to exercise

Background

Tie-stall housing of dairy cows is used extensively worldwide, despite of the welfare concerns regarding the restriction of voluntary movement and limitation of expression of the cows’ natural behaviour. The aim of this study was to compare the welfare quality of dairy cows kept in two types of tie-stall housing systems: with regular outdoor exercise and without access to exercise. In addition, the study investigated the relationship between different welfare measures of dairy cows kept in tie-stalls.

Methods

3,192 lactating cows were assessed using the Welfare Quality® assessment protocol for cattle in 80 commercial dairy farms, half of the farms providing outdoor access for the animals to exercise. The descriptive statistical indicators were determined for the assessed measures and for the welfare criteria and principle scores. The data obtained in the two housing types were compared and the correlation coefficients were calculated between the different welfare measures.

Results

The significant differences found between the two housing systems for the majority of the animal based measures indicate the positive effect of exercise on the welfare of tethered cows. Many of the animal welfare parameters correlated with each other. For the farms allowing the cows’ turnout in a paddock, pasture or both, the mean scores for the welfare criteria and principles were higher than for the farms with permanent tethering of the cows, except the criteria absence of prolonged hunger and expression of social behaviours. The lowest scores were obtained for the criterion positive emotional state, in both housing systems. With regard to the overall classification, none of the farms were considered excellent. In the not classified category were only farms with all-year-round tethering of the animals and in the enhanced category only farms where the cows had outdoor access.

Conclusions

The welfare quality of the investigated dairy cows was significantly better in the tie-stall farms which allow exercise for cows (paddocks, pasture or both) than in those which do not. In the light of our results we consider that dairy cattle welfare is not necessarily poor in tie-stall housing systems, its quality depending on the management practices.

Metritis in dairy cows: risk factors and reproductive performance

The objectives of this study were to assess the risk factors for metritis, its effects on milk yield and on reproductive performance, and the efficacy of ceftiofur therapy in Holstein dairy cows. Cows (n=303) from a commercial dairy herd in Argentina were studied. Cows were scored for body condition, and blood samples were collected on d -14, 7, 21, 31, 41, and 50 relative to parturition. Cows having a watery, purulent, or brown, and fetid vaginal discharge (VD) and rectal temperature ≤ 39.2°C were diagnosed as having clinical metritis, and those having a similar VD and rectal temperature >39.2°C were diagnosed as having puerperal metritis. Both clinical and puerperal metritis cows were randomly assigned to control (no treatment) or ceftiofur group (2.2mg/kg×3 consecutive days). Cure was declared if clear VD was observed at 21 d in milk (DIM). Blood samples were analyzed for nonesterified fatty acids, β-hydroxybutyrate, and blood urea nitrogen using commercial kits, and for insulin-like growth factor-1, insulin, and leptin by RIA. Data were analyzed with PROC MIXED, GENMOD, PHREG, and LIFETEST from SAS (SAS Institute Inc., Cary, NC). The risk for metritis increased with dystocia, retained fetal membranes, and dead calf [AOR (adjusted odds ratio)=2.58, 95% CI: 1.189-5.559], and as prepartum nonesterified fatty acids levels increased (AOR=1.001, 95% CI: 0.999-1.002). Conversely, risk decreased as prepartum insulin-like growth factor-1 increased (AOR=0.65, 95% CI: 0.349-1.219). Cows having either clinical or puerperal metritis produced less milk by 90 DIM than did healthy cows (2,236 ± 172 vs. 2,367 ± 77 vs. 2,647 ± 82 kg, respectively). Cows with puerperal metritis had lower risk for pregnancy by 100 DIM (AOR=0.189, 95% CI: 0.070-0.479) and a lower hazard rate for pregnancy by 150 DIM (hazard rate: 0.753, 95% CI: 0.621-0.911), and took longer to get pregnant (129 vs. 111 vs. 109 d, for puerperal metritis, clinical metritis, and healthy cows, respectively). Ceftiofur treatment was not associated with cure rate or milk yield but was related to increased risk for pregnancy at timed artificial insemination (AOR=2.688, 95% CI: 0.687-10.832), and for lower risk of reproductive cull (AOR=0.121, 95% CI: 0.014-1.066). In conclusion, abnormal calving and negative energy balance are associated with increased risk for metritis. Metritis, especially puerperal metritis, correlates with reduced milk production and poor reproductive performance. Finally, the likelihood for having a normal VD (indicative of cure) increased 2.6% for every day of increase in postpartum time and was 2 times higher for cows with clinical metritis than for those with puerperal metritis.

Prevalence of subclinical ketosis and relationships with postpartum diseases in European dairy cows

Subclinical ketosis (SCK) is defined as concentrations of β-hydroxybutyrate (BHBA) ≥ 1.2 to 1.4 mmol/L and it is considered a gateway condition for other metabolic and infectious disorders such as metritis, mastitis, clinical ketosis, and displaced abomasum. Reported prevalence rates range from 6.9 to 43% in the first 2 mo of lactation. However, there is a dearth of information on prevalence rates considering the diversity of European dairy farms. The objectives of this study were to (1) determine prevalence of SCK, (2) identify thresholds of BHBA, and (3) study their relationships with postpartum metritis, clinical ketosis, displaced abomasum, lameness, and mastitis in European dairy farms. From May to October 2011, a convenience sample of 528 dairy herds from Croatia, Germany, Hungary, Italy, Poland, Portugal, Serbia, Slovenia, Spain, and Turkey was studied. β-Hydroxybutyrate levels were measured in 5,884 cows with a handheld meter within 2 to 15 d in milk (DIM). On average, 11 cows were enrolled per farm and relevant information (e.g., DIM, postpartum diseases, herd size) was recorded. Using receiver operator characteristic curve analyses, blood BHBA thresholds were determined for the occurrence of metritis, mastitis, clinical ketosis, displaced abomasum, and lameness. Multivariate binary logistic regression models were built for each disease, considering cow as the experimental unit and herd as a random effect. Overall prevalence of SCK (i.e., blood BHBA ≥ 1.2 mmol/L) within 10 countries was 21.8%, ranging from 11.2 to 36.6%. Cows with SCK had 1.5, 9.5, and 5.0 times greater odds of developing metritis, clinical ketosis, and displaced abomasum, respectively. Multivariate binary logistic regression models demonstrated that cows with blood BHBA levels of ≥ 1.4, ≥ 1.1 and ≥ 1.7 mmol/L during 2 to 15 DIM had 1.7, 10.5, and 6.9 times greater odds of developing metritis, clinical ketosis, and displaced abomasum, respectively, compared with cows with lower BHBA blood levels. Interestingly, a postpartum blood BHBA threshold ≥ 1.1 mmol/L increased the odds for lameness in dairy cows 1.8 (95% confidence interval: 1.3 to 2.5) times. Overall, prevalence of SCK was high between 2 to 15 DIM and SCK increased the odds of metritis, clinical ketosis, lameness, and displaced abomasum in European dairy herds.

Uterine bacterial flora in postpartum Danish Holstein dairy cows determined using DNA-based fingerprinting: correlation to uterine condition and calving management

The overall aim of this study was to describe uterine bacterial flora during the postpartum period in Danish Holstein cows using the Terminal Restriction Fragment Length Polymorphism (T-RFLP) method. This method produces a pattern of nucleic acid fragments from the microorganisms present, reflecting the "fingerprint" of the actual microbial flora. As well as characterizing changes in flora with time from calving and between herds, data were examined for strong relations between uterine bacterial flora, calving management and uterine condition. In total 125 Holstein cows from five herds were included, and for each cow calving management was recorded. Cows were clinically examined on average 8 (range 0-19) and 28 (range 22-38) days after calving, and a uterine sample was taken for bacterial identification using T-RFLP. Milk samples were taken weekly for progesterone analysis. Bacteria were found in all cows at both examinations, and the flora was composed of many species, including species not traditionally reported to be present in the bovine uterus. The bacterial composition differed according to days from calving and herd. In all five herds Fusobacterium necrophorum, Pseudomonas/Acinetobacter and Bacteroides/Sphingobacterium/Prevotellaceae were among the most common at both examinations. In four herds there was a percentage decrease of F. necrophorum from first to second examination, and in all herds there was a percentage increase of Pseudomonas/Acinetobacter from first to second examination. No differences in bacterial flora were found between cows with different uterine scores, which were influenced by herd, calving difficulty and retained placenta.