Unraveling the immune and metabolic changes associated with metritis in dairy cows

The objective was to unravel the peripartum immune and metabolic changes associated with metritis in Holstein cows. Holstein cows (n = 128) had blood collected at -14, 0, 3, and 7 d relative to parturition (DRP). Flow cytometry was used to evaluate blood leukocyte counts, proportions, and activation. Total cells, live cells, single cells, monocytes (CD172α+/CD14+), polymorphonuclears (CD172α+/CD14-/SSChigh), B-cells (CD21+/MHCII+), CD4+ T-cells (CD4+), CD8+ T-cells (CD8+), and γδ T-cells (γδTCR+) were evaluated. Both CD62L and CD11b were used as markers of cell activation. Major histocompatibility complex class II was used as a marker of antigen presentation in monocytes. A Milliplex Bovine Cytokine/Chemokine 08-plex kit was used to evaluate plasma concentrations of IFN-γ, IL-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, and tumor necrosis factor-α. The body weight (BW) change prepartum was calculated as the difference between calving BW and prepartum BW divided by the number of days between measurements. Plasma fatty acids (FA) were measured at -14 and 0 DRP using untargeted gas chromatography with time-of-flight mass spectrometry. Data were analyzed by ANOVA for repeated measures. Cows that developed metritis (n = 57) had greater prepartum BW, prepartum BW loss, and greater FA concentrations at calving. Plasma FA at calving was positively correlated with IL-1β. Cows that developed metritis had persistent systemic inflammation, which was demonstrated by greater B-cell activation, greater pro-inflammatory cytokine concentrations, and greater cell damage pre- and postpartum. Postpartum, we observed greater polymorphonuclear cell activation and extravasation but lesser monocytes and CD4+ T-cells activation and extravasation, which suggests postpartum immune tolerance. Greater prepartum adiposity in cows that developed metritis may lead to systemic inflammation pre- and postpartum and immune tolerance postpartum, which may lead to failure to prevent bacterial infection, and development of puerperal metritis.

Metritis and clinical mastitis events in lactating dairy cows were associated with altered patterns of rumination, physical activity, and lying behavior monitored by an ear-attached sensor

Understanding changes in parameters recorded by automated health monitoring systems based on ear-attached sensors on the days immediately before and after diagnosis of metritis and clinical mastitis can help develop dairy cow health monitoring strategies. The objective of this observational cohort study was to characterize rumination time, physical activity, and lying time monitored by an ear-attached sensor before, during, and after clinical diagnosis (CD) of metritis and clinical mastitis. Lactating Holsteins monitored daily for 21 d in milk for detection of health disorders were retrospectively included in the no clinical health disorder group (NCHD; n = 616) if no disorders were diagnosed. Cows were included in the metritis (MET; n = 69) or clinical mastitis (MAST; n = 36) group if diagnosed only with nonsevere metritis (watery, reddish, and fetid uterine discharge with or without pyrexia) or nonsevere clinical mastitis (visibly abnormal milk secretion with or without signs of udder inflammation, with no pyrexia and no systemic signs of disease), respectively. Cows diagnosed with severe metritis (signs of metritis plus systemic signs of disease) or severe clinical mastitis (signs of mastitis plus pyrexia and systemic signs of disease), and cows diagnosed with nonsevere metritis or clinical mastitis plus another disorder within -7 to +7 d of CD of metritis or clinical mastitis diagnosis, were included in the metritis plus (MET+; n = 25) or the clinical mastitis plus (MAST+; n = 15) group, respectively. Cows were fitted with an ear-attached accelerometer to measure rumination time, physical activity, and lying time. Mean daily values, mean value absolute change, and relative change for the mean daily value from 3 or 5 d before CD to the nadir for cows with metritis and clinical mastitis, respectively, were analyzed with linear mixed models with or without repeated measures. Rumination time and physical activity were lesser, and lying time was greater for the MET and MET+ groups than for the NCHD group for most days from -4 to +7 d of CD of metritis. Generally, daily rumination time, physical activity, and lying time differences were greater and more prolonged between the MET+ and NCHD than between the MET and NCHD groups. Similarly, cows in the MAST and MAST+ groups had lesser rumination time and physical activity than cows in the NCHD group for several days before diagnosis. Lying time was greater for the MAST+ than the NCHD group on d -1 and 0 relative to CD. Absolute values and relative changes from 3 d before CD to the day of the nadir for rumination time and physical activity, or peak for lying time, were different for cows in the MET and MET+ groups than for the NCHD group. Similar results were observed for the MAST and MAST+ groups compared with the NCHD group. For cows with metritis, either an increase in rumination time and physical activity or a decrease in lying time was observed from the day of CD to resolution of clinical signs, but no changes were observed for the NCHD. Cows with clinical mastitis and the NCHD group had different rumination times, physical activity, and lying times on the day of CD and resolution of clinical signs, but cows with clinical mastitis had no significant changes from the day of CD to resolution of clinical signs. We conclude that cows affected by metritis and clinical mastitis presented substantial alterations of the patterns of rumination time, physical activity, and lying time captured by an ear-attached sensor. Thus, automated health monitoring systems based on ear-attached sensors might be used as an aid for identifying cows with metritis and clinical mastitis. Moreover, behavioral parameter changes after CD might be good indicators of resolution of clinical signs of metritis but not mastitis.

Associations between days in the close-up group and milk production, transition cow diseases, reproductive performance, culling, and behavior around calving of Holstein dairy cows

The objective of experiment I was to evaluate the association between days in the close-up group (DINCU) and milk production, early lactation diseases, reproductive performance, and culling. In experiment II behavioral changes associated with DINCU were evaluated using a neck-mounted sensor (Smarttag neck, Nedap Livestock Management, Groenlo, the Netherlands). Cow-lactations of 28,813 animals from 14,155 individual cows of 2 farms in northern Germany and western Slovakia, calving between January 2015 and December 2020, were included in the study. After exclusion of cows with a gestation length <262 and >292 d and cows with >42 DINCU data from 8,794 and 19,598 nulliparous and parous cows, respectively, were available for final statistical analyses. To analyze the association between DINCU and second test-d 305-d mature-equivalent milk projection, linear mixed models were calculated. Binary data (i.e., clinical hypocalcemia, hyperketonemia, retained placenta [RP], acute puerperal metritis [APM], mastitis, left displaced abomasum [LDA], first service pregnancy risk) were analyzed using logistic regression models. To analyze the association between DINCU and culling or death during the first 300 DIM Cox proportional hazards were used. To analyze the association between DINCU and behavior 7 d before to 7 d after calving (i.e., activity, inactivity, eating, ruminating time), linear mixed models were calculated. Nulliparous cows with a short (<10 DINCU) and a long stay (>30 DINCU) in the close-up group had a lower milk production an increased risk for hyperketonemia, RP, and APM compared with nulliparous cows with DINCU between 21 to 28 d. Parous cows with a short (<10 DINCU) and a long stay (>30 DINCU) in the close-up group had a lower milk production, an increased risk for RP and mastitis, a reduced first service pregnancy risk, and an increased culling risk, compared with parous cows with DINCU between 21 to 28 d. Furthermore, the risk for clinical hypocalcemia and LDA was increased in parous cows with >30 DINCU compared with parous cows with <30 DINCU. The risk for APM was increased in parous cows with <10 DINCU compared with parous cows with >10 DINCU. In nulliparous cows no association was found between DINCU and the risk for left displaced abomasum and mastitis. In experiment II, cows with 7 and 35 DINCU had an impaired behavior around calving compared with cows with 14, 21, and 28 DINCU. During the last 7 d before parturition, these cows were more inactive and had a reduced eating and ruminating time. After calving, cows with 7 DINCU spent less time eating. In conclusion, cows with <10 DINCU and cows with >30 DINCU had a lower milk production, a higher risk to incur diseases and an impaired behavior, especially before calving.