Phagocytic activity in blood and proliferation of peripheral blood lymphocytes during the perinatal period in primiparous sows.

The objective of this study was to determine whether phagocytic activity in blood and proliferation of peripheral blood lymphocytes are impaired during perinatal period. The study comprised 18 primiparous sows (Landras × Large White) free from clinical signs of diseases. During the experiment blood samples were collected three times from each sow. Sampling was performed on three different dates, always from all sows at once. At the first date of sampling sows were 21 ± 3 days before parturition, at the second date ± 1 day around parturition time and at the third date 21 ± 3 days after parturition. Phagocytic activity of monocytes and granulocytes was assessed in heparinized whole blood with addition of fluorescein isothiocyanate (FITC)-labelled opsonized bacteria Escherichia coli and the percentage of phagocytes which have ingested bacteria was measured as fluorescence activity by flow cytometry. The percentage of phagocyting monocytes and granulocytes was lowest at parturition (72.6 ± 16.37, 52.4 ± 20.59) and significantly increased within the next 21 ± 3 days (86.5 ± 6.16, 69.89 ± 5.80). Similarly, the phytohemagglutinin (PHA) (10 µg/ml) stimulated in vitro lymphocyte response was suppressed by parturition in primiparous sows (p < 0.001).

Feed contaminated with Fusarium toxins alter lymphocyte proliferation and apoptosis in primiparous sows during the perinatal period.

Two groups of pregnant primiparous sows (day 89 ± 2 of gestation) were 54 days (± 1 day) fed either with an experimental diet (5.08 mg kg(-1) deoxynivalenol--DON, 0.09 mg kg(-1) zearalenone and 21.61 mg kg(-1) fusaric acid) or control diet (0.25 mg kg(-1) DON). The consummation of feed was significantly higher in the control group. Lymphocyte stimulation in culture from peripheral blood lymphocytes (PBL) was measured by BrdU incorporation test using two different concentrations of mitogen PHA 10 and 20 µg ml(-1), two different concentrations of DON (5 and 1 µg ml(-1)) and a combination of both, PHA and DON (PHA 10+DON 5, PHA 10+DON 1 and PHA 10+DON 0.1 µg ml(-1)). The lymphocyte proliferation, except for PHA 10 µg ml(-1), was significantly higher in the experimental group. Further on, using the photometric enzyme immunoassay, the apoptosis was studied in non-stimulated 72h lymphocyte culture or stimulated with 1 µg ml(-1) of DON. The significantly higher apoptosis was in non-stimulated lymphocyte cultures from the experimental group (P = 0.036). The results suggest that such feed may affect the peripheral lymphocyte population in the direction of their proliferation response and programmed cell death.

Effects of a deoxynivalenol-contaminated diet on the reproductive performance and immunoglobulin concentrations in pigs.

Two groups of 10 pregnant gilts (89 +/- 2 days gestation) were fed either an experimental diet that contained 5.08 mg/kg deoxynivalenol, 0.09 mg/kg zearalenone and 21.6 mg/kg fusaric acid, or a control diet that contained 0.29 mg/kg deoxynivalenol, <0.02 mg/kg zearalenone and <0.77 mg/kg fusaric acid. The concentrations of immunoglobulins were measured in sera of the gilts and in the colostrum and serum of the piglets by radial immunodiffusion. The feed consumption of the sows fed the experimental diet was significantly lower and the overall growth rate of their piglets was significantly reduced. On average, parturition took 80 minutes longer in sows fed the experimental diet. On day 17 after parturition, the concentration of IgM in the serum of the experimental gilts was significantly higher, but the concentration of IgA in their colostrum was significantly lower, than in the control gilts. In the serum of the piglets 12, 24 and 48 hours after first suckling, the concentrations of IgA and IgG were significantly lower in those farrowed by the sows fed the experimental diet than in those farrowed by the sows fed the control diet.