Cervicalmucusisaviscoelasticsecretionofconstantly secreting mucus producing cells of the endo-cervix [1] and acts as a mechanical barrier to prevent intruding organisms. It is a complex biomaterial having a vital protective function in the cervix during pregnancy. Bovine cervical mucus exists into two phases, aqueous and gel [2]. The aqueous phase contains mostly water (92-95%) with some ions and metabolites [3]; whereas the glycoproteins (mucins) are the major component of the gel phase [4]. Colour, appearance, pH and electrical conductivity along with other rheological properties like Spinnbarkeit value, flow elasticity, viscosity, thixotrophy, and arborisation pattern are the most important properties in relation to fertility. These properties vary with endocrinological status of reproductive cycle and directly associated with the estrogen: progesterone ratio and fertility status of dairy animals [5]. Basically two types of cervical mucus are observed, estrogenic and gestagenic [6] which can be further divided into various subtypes.

The rheological properties of cervical mucus becomes more plentiful, watery and less viscous, during follicular phase, which facilitates the transport of spermatozoa in the female reproductive tract. However, it becomes opaque, thick, viscous and scanty during luteal phase not favourable to sperm migration [2]. Cervical secretion becomes more copious and watery during the estrogen dominating phase of ovarian cycle while the viscosity of mucus increases under high progesterone concentration. Therefore may be used in determining the stage of estrus for fixing an optimum time of insemination in farm animals. The occurrence of crystallization is common to all types of mucus. But degree of crystallization/arborisation pattern in cervical mucus is under the control of two ovarian hormones., estrogen and progesterone. The phenomenon of crystallization in cervical mucus progresses under the influence of estrogen where as progesterone diminishes the formation of arborisation pattern [3]. Thus it