0
Sows were treated with progestagen (20 mg/d) from d 109 to d 112 of gestation (T112, n=6) or from d 109 to d 113 (T113, n=8) or were not treated (Control, n=10). Colostrum production was estimated during 24 h starting at the onset of parturition using piglets’ weight gains. Colostrum samples were collected at the onset of parturition then 6, 12, 24, 36 and 48 h later and were assayed for concentrations of Na+ and K+ (all samples) and immunoglobulin G (IgG, at t0, t24 and t48). Gestation length was longer in T113 than in Control group (116.3±0.2 vs 114.6±0.3 days; P<0.001) and intermediate in T112 group (115.8±0.5 days). Colostrum production (4.1±0.2 kg), litter size (13.9±0.7 piglets born alive) and litter birth weight (17.2±0.8 kg) were not different between groups (P>0.1). Concentrations of IgG in colostrum were greater (P<0.05) in Control than in treated sows (T112 + T113; 59.1±6.8 mg/ml vs 48.0±4.0; 8.0±2.2 vs 5.4±1.4; 2.4±0.4 vs 0.6±0.2 at t0, t24 and t48 respectively). In literature, concentrations of IgG in colostrum have been suggested to partly depend upon the permeability of tight junctions between epithelial mammary cells, which can reduce paracellular transfer of IgG. In the present experiment, Na+:K+ ratio in colostrum was lower (P<0.05) in T113 than in Control sows, suggesting a reduced permeability of the mammary epithelium. However, Na+:K+ ratio did not differ between T112 and Control sows (P>0.1). Further analyses, especially of prolactin concentrations, are needed to explain the reduction in IgG contents.
It is concluded that progestagen treatment in gestating sows did not influence colostrum yield but reduced IgG content.
A Foisnet, and H Quesnel, 2009, EAAP 60th Annual Meeting, Barcelona, 393.
