Fig. 16

Sensitivity analysis results for the time of first ovulation post partum. A sensitivity analysis was performed to assess the influence of all model parameters on the time of first ovulation after calving as described by Eq. (27). a shows the change in the timepoint of first ovulation after perturbation of single parameters by +10%, whereas b shows the change in the timepoint of first ovulation after perturbation by -10%. Note that in the two subplots a and b only the numerator of \({\hat S}_{y}^{i}\) is plotted since the denominator is independent of the parameter index i. The two most influential parameters are T₁ (parameter 91) and \(T_{P4}^{Foll}\) (parameter 33). A change of the parameter T₁ by +10% results in a later occurrence of ovulation (Fig. 16c). On the other hand, a decrease in the value of \(T_{P4}^{Foll}\) by -10% stimulats the decay of follicular function, which causes a prolongation of the anovulatory period to day ≈120