Abstract
A numerical simulation of freezing-thawing protocols applicable to mammalian spermatozoa is described and validated in the boar and the ram. Original aspects include: (1) the simulation of all steps of the technique from ejaculation to thawing, (2) the simulation of complex extenders really usable in field conditions and extender properties in non-ideal conditions, (3) the sequential extender changes within a protocol for simulation of dilutions, additions, etc. (4) the introduction of a new concept, the “molecular chicanes” which reconciles theoretical and experimental results, (5) the introduction of specific cell models and (6) the prediction of different cell injuries at various depths in flat and cylindrical plastic cryocontainers. The calculated data indicate when, where and why cells are affected during each step of the technique and can therefore help to increase the total number of living spermatozoa or to devise new techniques rapidly. For validation, calculated data are compared to experimental and literature results. In boars and rams, simulations and observations generally differ by less than 5%.