Progesterone Plasma Levels
The progesterone levels in the plasma of each individual gilt are presented in Figure 1A for controls and in Figure 2A for IFN-treated gilts. In both groups, plasma progesterone levels dropped between Day 14 and Day 16 of the estrous cycle (time effect: p < 0.0001). This pattern was similar in both groups; indeed, the treatment and the interaction between treatment and time were not significant ip > 0.27 and p > 0.33, respectively). The mid-decrease of progesterone occurred on Days 16, 14.7, 15.6, 15.1, and 14.7 and on Days 14, 14.2, 13.6, and 16.4 of the estrous cycle for the IFN-treated gilts and the controls, respectively. There was no significant difference between the means of the two groups for this parameter (15 ± 1.25 and 14.5 ± 0.57, p > 0.37). The means of the progesterone values observed for the two groups are presented in Figures IB and 2B with the fitted levels. Once again the patterns appeared very similar. There was thus no significant increase in the duration of the progesterone phase after IFN treatment.
Day of Estrus
Estrus began on Days 19, 20, 19, 20, and 20 and on Days 18, 20, 19, and 20 for the IFN and control groups, respectively. The mean value of the day of return to estrus for the IFN group was 19.6 ± 0.55, which was not significantly different (p > 0.5) from that observed for control (19 ± 0.96). levitra super active plus
FIG. 1. A) Jugular progesterone levels in individual controls. B) Means of the progesterone levels in controls (dots) and curve fitted with the nonlinear model; the parameters of the nonlinear model were BL = 0.3 ng/ml, С = 24 ng/ml, R = 0.9 ng/ml/day, Tinf = 14.4 days; this value of Tinf is very close to the mean value of the individual Tinfs (14.5).
FIG. 2. A) Jugular progesterone levels in individual IFN-treated gilts. B) Means of progesterone levels in the IFN-treated gilts (dots) and curve fitted with the nonlinear model; the parameters of the nonlinear model were BL = 0.5 ng/ml, С = 22 ng/ml, R = 2.2 ng/ml/day, Tinf = 15.2 days; this value of Tinf is very close to the mean value of the individual Tinfs.