The aim of this study was to determine changes of reactive oxygen species (ROS), serum antioxidant capacity (SAC), oxidative stress index (OSi), and α-tocopherol (α-T) during the periparturient period in healthy and mastitic cows and to further investigate whether these parameters can be used as a tool for identifying cows at higher risk of developing mastitis. Blood samples from 110 dairy cows from two commercial farms were obtained at dry-off, calving, and 30 days post-partum. Healthy cows formed group A (n = 90) and mastitic cows B (n = 20). Blood serum was obtained by centrifugation, and the aforementioned parameters were determined. A general linear model was used for analysing the associations among the determined blood parameters, the health of the animals’ udder, and the sampling time. ROS and OSi values were higher (P < 0.001) by a respective 14% and 26%, and SAC values lower (P < 0.001) by 10% in group B than in group A at calving. ROC curve analysis revealed that all determined parameters at calving and α-T at dry-off and 30 days post-partum had excellent or acceptable predicting ability for mastitis incidence. This information provides a tool for early identification of cows at high risk of developing mastitis, allowing the implementation of intervention strategies.

The objectives of this study were to determine the role of a fall in pre-calving body condition score (BCS) in postpartum metabolic status and reproductive outcomes, and gauge the indicativeness of blood metabolites during the transition period. Cows were grouped based on BCS loss between days −14 ±3 and 0 relative to calving. Cows that lost no BCS were the BCS control group (BCS-C), cows that lost 0.25 BCS points the low BCS loss group (BCS-L), and those that lost 0.5 points or more the high BCS loss (BCS-H) group. Blood was taken on days −14 ±3, 3, 14, and 30 ±4 for determination of comprehensive metabolic panel biomarker levels. Beta-hydroxybutyric acid (BHBA) levels were quantified on postpartum examination days. Vaginal discharge scores, ovarian activity on day 30 ±4, and subsequent fertility parameters were evaluated. The BCS-H cows had lower mean Ca concentrations before calving and on day 3, when the group’s BHBA and CK were higher (P < 0.05); on day 14 they had higher AST concentrations (P < 0.05). The BCS-L cows had greater bilirubin levels (P < 0.05). The BCS-H cows had lower cyclicity and higher endometritis rates. First service pregnancy rates were 50%, 50%, and 61.9%, open days 96.8, 95.75, and 89.2, and overall pregnancy rates 56.25%, 65%, and 80.95 % in the BCS-H, BCS-L, and BCS-C groups, respectively. Prepartum BCS loss of ≥ 0.5 points could be associated with Brown Swiss cow low Ca and BHBA concentrations early postpartum, and with subsequent uterine health and overall pregnancy rate. Prepartum Ca concentration might be a prognostic biomarker for postpartum metabolic status and reproductive outcomes.

Introduction: The aim of this study was to investigate the relationship between body condition score (BCS) determined on the dry-off day, calving day, and in the first month of lactation, its changes during the dry period and early lactation, and periparturient indices and fertility in high-producing dairy cows. Material and Methods: The experiment was conducted in two herds: A and B, located in Western Poland. The studies were conducted on 116 and 108 Polish Holstein-Friesian dairy cows respectively, with an average milk yield of >10 000 kg/305-day lactation. The experiment included the dry period (-56 d to the calving day), the calving day, and early lactation (from +1 to +56 d). The experimental factor was BCS (0 to 5-point scale). The BCS was performed by one person on day -56, on parturition day (in the first 12 h after calving) and on day 30 of lactation. Results: A decrease in BCS (≥-0.25) in herd A during the dry period accelerated the planned calving period by 7.3 d. In the group of cows with BCS <3.25 on the dry-off day, the lowest artificial insemination index (1.80), the shortest period of insemination services (25 d), and days open (87 d) were recorded. Moreover, cows with BCS < 3.25 at calving had the shortest days open (91 d). BCS >3.50 in the first month of lactation (30 d) resulted in the extension of uterine involution period (56 d). Improvement of BCS during the dry period shortened the anoestrus (60 d) in herd A and the period of insemination service (60 d) in herd B. However, in this group (IM BCS ≥ 0.25) of cows the day of the highest artificial insemination index (2.50) in herd B was analysed. Conclusion: The body condition on the dry-off day and at calving, as well as its deterioration in the first month of lactation, have a considerable effect on fertility indices in dairy cows, thus confirming the advisability of its regular monitoring during routine operations connected with the management of a dairy cattle herd.

Introduction: The transition period is the most challenging time for dairy cattle, which is characterised not only by negative energy balance but also by fatty tissue mobilisation.Material and Methods: The efficiency of energy pathways, β-oxidation in WBC and glycolysis in RBC (based on deoxyglucose transmembrane transport) were estimated. Insulin in blood plasma was determined using ELISA.Results: After calving and up to one month after delivery, a significant drop in blood plasma level was noticed, simultaneously with a rise in β-oxidation from 18.93 ±3.64 to 30.32 ±5.28 pmol/min/mg protein in WBC. A strong negative correlation between these two indices (r = −0.68) was found. During the period of transition to lactation an increase in glucose cross-membrane transportation from 41.44 ±4.92 to 50.49 ±6.41 μmol/h/g Hb was observed. A strong positive correlation between glucose transportation in RBC and β-oxidation in WBC (r = 0.71) was noticed. These data are in agreement with results of studies on dairy cows using liver slices from dairy cows in late pregnancy and different stages of lactation, in which changes in gene expression were analysed.Conclusion: It seems that measuring fatty acids oxidation and glycolysis using isolated blood cells may be an adequate and relatively simple method for energy state analysis to estimate the state of dairy cow metabolism and animal health.

Introduction: The aim of the study was to investigate changes in the serum levels of adiponectin and TNF-α, as well as insulin sensitivity, and to elucidate the possible relationship among the parameters and negative energy balance during the periparturient period of dairy cows.Material and Methods: Thirty primiparous Holstein dairy cows were selected for the study. Blood samples were collected from each cow seven days before the expected calving date, on the calving day, and 7, 14, and 21 days after calving. Blood non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), glucose, insulin, adiponectin, and TNF- α levels were measured. Revised Quantitative Insulin Sensitivity Check Index (rQUICKI) was calculated using data on NEFA, insulin, and glucose concentrations.Results: When compared to prepartum levels, serum concentration of adiponectin significantly increased on day 21 postpartum. The rQUICKI increased and NEFA levels decreased on day 7 after parturition. Insulin and glucose levels decreased on days 7, 14, and 21 postpartum when compared with prepartum levels. BHBA levels decreased on day 21 and TNF- α concentration also decreased on days 7, 14, and 21 postpartum. Adiponectin levels positively correlated with NEFA during the preparturient period. Negative correlation was detected between adiponectin and rQUICKI on calving day and on 14ᵗʰ day after parturition. TNF- α concentration positively correlated with glucose levels on day 7 prepartum and on 21ˢᵗ day postpartum and with rQUICKI on 21ˢᵗ day postpartum. Negative correlation was detected between adiponectin level and insulin sensitivity.Conclusion: Based on the results of the study, we concluded that adiponectin could possibly increase insulin sensitivity when blood NEFA concentrations are elevated.

Introduction: The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels under seasonal variations in dairy cows during transition period, and to assess the relationship between chosen reproductive parameters, GSH-Px, and MDA. Material and Methods: Holstein cows calving in January were assigned into winter group (n = 42), while cows calving in August were assigned into summer group (n = 42). Blood samples were collected from the jugular vein 21, 14, and 7 days before calving, at calving (0 day), and 7, 14, and 21 days after calving. Reproductive parameters obtained from farm records were evaluated. Results: In both groups of cows, GSH-Px activity decreased from 21 days before calving to day 0, and it gradually continued to increase until 21 days after calving. GSH-Px activity was higher in winter group compared to summer group during the transition period (P < 0.05). MDA levels in both groups increased over time starting from 21 days before calving to 0 day, but it gradually decreased thereafter. MDA levels were higher in summer group compared to winter group during the transition periods (P < 0.05). Summer group of cows showed higher intervals of calving-to-oestrus, calving-to-conception, and higher insemination index (P < 0.01). Negative correlation was recorded between GSH-Px and MDA during all examination days (P < 0.01). MDA levels correlated with calving to conception interval on day 21 before calving and day 0 (P < 0.01) and insemination index on day 0 and 21 days after calving (P < 0.01). GSH-Px activity was negatively correlated with calving to conception interval on day 21 before calving, day 0, and 21 days (P < 0.01) after calving. Negative correlation on day 21 before calving and day 0 was also determined between GSH-Px and insemination index (P < 0.01). Conclusion: This study showed that blood oxidant and antioxidant levels have affected the fertility parameters in cows under seasonal variations.

The objective of this study was to evaluate the effect of late-gestation vaccination of beef heifers with 2 doses of a killed-virus (KV) vaccine containing bovine herpesvirus 1 (BoHV-1), bovine viral diarrhea virus 1 (BVDV-1), and bovine viral diarrhea virus 2 (BVDV-2) on the serum concentrations of antibody against BoHV-1, BVDV-1, and BVDV-2 in heifers and their calves and on the IgG concentration in the calves. Of the 47 pregnant beef heifers selected, 26 received 2 doses of the vaccine at 6.5 to 8 mo of gestation (at pregnancy check), and 21 received 2 doses of saline. The mean log2 serum titers of neutralizing antibody against BoHV-1, BVDV-1, and BVDV-2 before vaccination did not differ significantly between the treatment groups; however, at calving all 3 mean titers were significantly greater (P < 0.05) in the vaccinated heifers than in the control heifers. At 24 h after birth the mean serum IgG levels in the calves did not differ significantly between the 2 groups, at 30.18 and 32.28 g/L, respectively (P < 0.05); however, the mean log2 serum titers of antibody to all 3 viruses were greater in the calves nursing colostrum from the vaccinated heifers than in the calves nursing colostrum from the nonvaccinated heifers and significantly so for BoHV-1 and BVDV-1 (P < 0.001 and P = 0.009, respectively). Thus, late-gestation vaccination of beef heifers could result in a greater and more consistent deposition of specific antibodies in colostrum, reducing the variability of initial titers in calves and increasing the duration of maternal immunity.

OBJECTIVE To determine serum and tissue concentrations of gallium (Ga) after oral administration of gallium nitrate (GaN) and gallium maltolate (GaM) to neonatal calves. ANIMALS 8 healthy neonatal calves. PROCEDURES Calves were assigned to 1 of 2 groups (4 calves/group). Gallium (50 mg/kg) was administered as GaN or GaM (equivalent to 13.15 mg of Ga/kg for GaN and 7.85 mg of Ga/kg for GaM) by oral gavage once daily for 5 days. Blood samples were collected 0, 0.25, 0.5, 1, 2, 4, 8, 12, and 24 hours after Ga administration on day 1; 4 and 24 hours after Ga administration on days 2, 3, and 4; and 4, 12, and 24 hours after Ga administration on day 5. On day 6, calves were euthanized and tissue samples were obtained. Serum and tissue Ga concentrations were measured by use of mass spectrometry. RESULTS Data were adjusted for total Ga dose, and comparisons were made between the 2 groups. Calves receiving GaM had a significantly higher dose-adjusted area under the curve and dose-adjusted maximum serum Ga concentration than did calves receiving GaN. Despite receiving less Ga per dose, calves receiving GaM had tissue Ga concentrations similar to those for calves receiving GaN. CONCLUSIONS AND CLINICAL RELEVANCE In this study, calves receiving GaM had significantly higher Ga absorption than did calves receiving GaN. These findings suggested that GaM might be useful as a prophylactic agent against Mycobacterium avium subsp paratuberculosis infection in neonatal calves.

Persistence of the oxytocin receptor (OTR) in the bovine uterus during the first 7 d after calving was investigated by means of immunohistochemical staining. Immunoreactive OTRs were present in different locations in the uterus on almost all days except day 2, when staining was seen only in the endothelium of blood vessels in the endometrium and myometrium. This finding supports the hypothesis that oxytocin may be ecbolic in cows through the 1st week post partum, but further studies are required to assess the receptor functionality during this period.

This study investigated epigenetic mechanisms by which DNA methylation affects the function of bovine adaptive immune system cells, particularly during the peripartum period, when shifts in type 1 and type 2 immune response (IR) biases are thought to occur. Stimulation of CD4+ T-lymphocytes isolated from 5 Holstein dairy cows before and after parturition with concanavalin A (ConA) and stimulation of CD4+ T-lymphocytes isolated from 3 Holstein dairy cows in mid-lactation with ConA alone or ConA plus dexamethasone (Dex) had significant effects on production of the cytokines interferon gamma (IFN-γ, type 1) and interleukin 4 (IL-4, type 2) that were consistent with DNA methylation profiles of the IFN-γ gene promoter region but not consistent for the IL-4 promoter region. ConA stimulation increased the production of both cytokines before and after parturition. It decreased DNA methylation in the IFN-γ promoter region but increased for IL-4 promoter region. Parturition was associated with an increase in IFN-γ production in ConA-stimulated cells that approached significance. Overall, DNA methylation in both promoter regions increased between the prepartum and postpartum periods, although this did not correlate with secreted cytokine concentrations. Dexamethasone treated cells acted in a manner consistent with the glucocorticoid’s immunosuppressive activity, which mimicked the change at the IFN-γ promoter region observed during parturition. These results support pregnancy as type 2 IR biased, with increases of IFN-γ occurring after parturition and an increase in IL-4 production before calving. It is likely that these changes may be epigenetically controlled.