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This study was part of a larger study that addressed the effects of marine algae (ALG) supplementation in the ration of high yielding periparturient dairy cows. The objectives were to induce milk fat depression (MFD) in early lactation by feeding docosahexaenoic acid (DHA) from ALG and to determine the effects on milk production, milk components and metabolic status early post partum. This study focuses on the oxidative status in the plasma during the ALG supplementation. Plasma samples were collected from 16 Holstein Friesian cows at the day of parturition and at −1, 2, 4 and 6 weeks relative to calving with half of the cows receiving the ALG supplement (44 g DHA/d) from 3 weeks pre partum on. The following parameters were measured in plasma: ferric reducing ability of plasma (FRAP), α-tocopherol level, glutathione peroxidase activity (GSH-Px) and thiobarbituric acid reactive substances (TBARS) concentration. There was a significant effect of time for FRAP and α-tocopherol indicating changes in the plasma oxidative status around parturition. The ALG supplementation was successful in creating a milk fat depression (MFD) but could not improve the energy balance. Feeding of ALG significantly increased lipid peroxidation as measured by TBARS, probably through their high content of n-3 polyunsaturated fatty acids.  相似文献   
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Bovine neonatal pancytopenia (BNP) is a bleeding and pancytopenic syndrome in neonatal calves, which recently emerged all over Europe. The present study tested whether antibodies directed against calf leukocytes are present in sera from known BNP dams. Sera from BNP dams (n=11) were combined with leukocytes from 11 calves (5 BNP survivors and 6 controls). After adding a fluorescein conjugated F(ab')(2) fragment of rabbit anti-bovine IgG (H&L) the level of antibody binding was measured by flow cytometry. As control groups both sera from dams from BNP affected (n=48) as from unaffected (n=54) herds were combined with leukocytes from the same calves. With sera from BNP dams, antibody binding could be visualised by immunofluoresence in both peripheral blood as in bone marrow smears. Mean fluoresence intensity values of all leukocyte subpopulations were significantly higher for the BNP dams compared to both control groups (P<0.01). BNP dams showed significantly more antibody binding on multiple leukocyte subpopulations of both BNP survivors and control calves and this from cut off values of MFI 100 onwards (P<0.01). The BNP survivor calves reacted significantly more often with sera from the BNP dams than the control calves (P<0.01). In conclusion the present study supports the hypothesis that BNP is an immune-mediated disease.  相似文献   
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Natural antibodies (NAb) are defined as antibodies that circulate in normal healthy individuals under the absence of deliberate antigenic stimulation. Two types of NAb are distinguished: NAb towards exogenous antigens and NAb towards autoantigens (N(A)Ab). The objectives of the current study were threefold. First, we studied the relation between metabolic health and concentrations of NAb binding keyhole limpet hemocyanin (KLH) or lipopolysaccharide (LPS) in milk and plasma of dairy cows in early lactation. Second, we determined the presence of N(A)Ab binding transferrin, myosin and thyroglobulin in bovine milk. Third, we studied the relation between N(A)Ab in bovine milk and mammary health. For the first objective, dairy cows were either fed a control (C) (n = 8) or a diet where 2 kg of concentrates were replaced by an iso-energetic concentrate containing marine algae (ALG) from week −3 till 8 postpartum (experiment 1). Plasma and milk samples were analyzed weekly for NAb binding either KLH or LPS. Plasma was analyzed for glucose, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA). For the second and third objective, milk samples were collected weekly from 96 dairy cows from week 2 till 9 postpartum and analyzed for milk composition and N(A)Ab binding myosin, transferrin and thyroglobulin (experiment 2). For both datasets, N(A)Ab titers are expressed as 2log values of the highest dilution giving a positive reaction. Data are expressed as means ± SEM. Repeated observations were analyzed in a mixed model. In experiment 1, no diet effect (P > 0.05) was observed on NAb binding LPS in plasma or milk, NAb binding KLH in milk was greater (P = 0.05) for cows fed the control diet. Concentration of NAb binding KLH and LPS in plasma was negatively related to plasma NEFA concentration (P < 0.05). In experiment 2, NAb binding myosin (5.66 ± 0.06), thyroglobulin (4.85 ± 0.06), and transferrin (5.76 ± 0.07) were identified in milk. Clinical mastitis incidence (9%) tended to be positively related to concentration of NAb binding myosin (P = 0.06) and negatively related to Nab binding transferrin (P = 0.08). In conclusion, NAb binding KLH and LPS in plasma and milk are related to metabolic health, as indicated by plasma NEFA concentration. Furthermore, this study demonstrates the presence of N(A)Ab in bovine milk and shows trends for a relation between N(A)Ab binding auto-antigens and mastitis. Future studies should confirm these trends and shed light on the predictive value of N(A)Ab in bovine milk for mammary health.  相似文献   
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Objectives of this study were twofold: (i) to assess the association between polymorphonuclear (PMN) counts and chronic alterations within the bovine endometrium and (ii) to determine the distribution of inflammation throughout the endometrium of clinically healthy dairy cows. Holstein‐Friesian cows (n = 32) from a single dairy farm were selected for this experiment. Before slaughtering, a complete reproductive examination was performed to discard any type of clinical disease. After slaughtering, reproductive tracts were collected, and the endometrium was sampled at 8 pre‐defined locations. At each location, endometrial biopsies (EBs) and cytology (CY) samples were harvested. Histopathology samples were stained with haematoxylin–eosin (EB‐HE) and naphthol‐AS‐D‐chloroacetate‐esterase (EB‐naphthol), while CY samples were stained with Wright–Giemsa. In the EB‐HE samples, parameters assessed were epithelium height, mononuclear cells infiltration, lymphocytic aggregates, periglandular fibrosis, angiosclerosis and haemorrhage. In EB‐naphthol and CY slides, PMNs counts were evaluated. Binomial logistic regression was used to assess the association between the number of PMNs present in both the EB‐naphthol and CY samples and alterations identified in the EB‐HE samples and to analyse the distribution of the histopathological alterations (EB‐HE). A Poisson mixed‐effect model was used to analyse the distribution of PMNs within the endometrium. A significant positive association was found between the PMN counts and the mononuclear cells infiltration. The presence of erythrocytes was associated with higher odds to detect PMNs in the stratum compactum. Significantly, higher infiltration of PMNs and mononuclear cells were detected in the uterine body and the right horn region. Concluding, CY is a technique that allows the evaluation of PMN counts and therefore only evaluates active inflammation. A complete assessment of endometrial health can only be obtained using EB. To optimize the sensitivity to diagnose endometrial inflammation in cows, adjacencies of the corpus uteri should be considered as the preferred region to harvest samples.  相似文献   
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