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A compartmental model describing changes in progesterone concentrations during the oestrous cycle
Susanne Meier1, John R Roche, Eric S Kolver
1DairyNZ Ltd, Hamilton, New Zealand. Susanne.Meier@DairyNZ.co.nz
This study developed a mathematical model to analyze plasma progesterone concentrations during the bovine estrous cycle. The model defines parameters for progesterone appearance and disappearance, identifying distinct profile shapes like peaked, structured, and flat top.
Area of Science:
- Reproductive Biology
- Mathematical Modeling
- Endocrinology
Background:
- Plasma progesterone concentrations are critical indicators of the bovine estrous cycle.
- Understanding progesterone dynamics is essential for reproductive management in cattle.
- Previous models lacked the precision to differentiate progesterone profile shapes.
Purpose of the Study:
- To develop a mathematical model for plasma progesterone concentrations in cows.
- To define parameters for progesterone appearance and disappearance during the estrous cycle.
- To identify and analyze distinct shapes of progesterone profiles.
Main Methods:
- Utilized daily plasma progesterone data from 27 cows.
- Developed a compartmental model with appearance and modulating functions.
- Employed shape-based clustering to categorize progesterone profiles into 'peaked', 'structured', and 'flat top' groups.
Main Results:
- The model successfully simulated progesterone profiles and defined key parameters.
- Identified significant differences in apparent progesterone appearance duration among profile shapes (flat top > structured > peaked).
- Found no significant differences in total appearance, mean appearance rate, or disappearance rate across profile shapes.
Conclusions:
- A novel mathematical model accurately describes progesterone dynamics in the bovine estrous cycle.
- The model allows for the characterization of progesterone profiles based on their unique shapes.
- This tool can aid in exploring the relationship between progesterone profile characteristics and reproductive outcomes.
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