Cervical mucus characteristics and hormonal status at insemination of Holstein cows.

The present study was carried out to characterize the cervical mucus (CM) collected when inseminating Holstein cows and to relate the secretion pattern with pregnancy. The mucus was collected from mid-cervix of 64 cows with spontaneus estrus (SE) and induced estrus (IE). The quantity, pattern and consistency of the mucus, pH, arborization patterns and the sperm motility were observed. The levels of progesterone and estradiol 17β in serum were also determined. Pregnancy detection was performed by means of transrectal ultrasonography 60 days after insemination. Mucous secretion of cows with SE was significantly different from those with IE, showing a lower degree of crystallization (SE 2.00; IE 2.75) and a lower level of steroid hormones (P4: SE 0.17 ng/ml and IE 0.33 ng/ml (t 1.99547 α 0.05); E2: SE 30.95 pg/ml and IE 47.76 pg/ml (t 1.99495 α 0.05). Progesterone level was significantly lower and estrogen significantly higher in pregnant cows (P) in relation to that observed in non pregnant females (N) (P4: P 0.20 ng/ml and N 0.44 ng/ml (t 1.99602 α 0.05); E2: P 54.77 pg/ml and N 40.75 pg/ml (t 1.99505 α 0.05). In conclusion pregnancy was associated with acopious, clear and watery discharge (similar to egg white), with an arborization degree of 2.25, presence of atypical fern leaves together with rosette formations and needles or thorns on rails due to low levels of progesterone accompanied by high concentrations of estrogens.