Comparison of three techniques in the preparation of samples for the crystallization of cervical flow in lactating dairy cattle

Abstract

The objective was to compare three techniques of sample preparation for cervical flow crystallization (pressure imprint, touch imprint and smear), analyzing the tree forms (crystallization) as a characterization of the cervical flow of dairy cattle, according to the day of collection and moment of the estrous cycle. Ten clinically healthy, multiparous Holstein Friesian dairy cows were sampled and 30 to 50 days postpartum. Each was collected from the vaginal cervix using a disposable pipette and a 50cc syringe. The two imprints and the smear were prepared on slides, with two-step protocol according to the methodology of Prado et al. (2012). The samples were then allowed to dry in the environment and the microscope was read with a higher magnification objective (40X) to observe the formation of the crystals, these procedures were performed in 4 different moments of the estrous cycle (0, 7, 14, 21 days). To quantify the crystallization, a scale from 0 to 4 was used, which varies depending on the formation of typical crystals at least formation or absence. At day 0, 7, 14, 21, the crystallization level in the three techniques had significant difference (P <0.05). At day 0, 50% of the samples processed by the touch imprint and pressure imprint showed typical formation compared to 20% that were processed by the smear technique. On day 7, 80% of the samples processed by touch imprint, 90% of the smear technique and 70% of the pressure imprint, present atypical crystals. On day 14, 60% of the samples processed by the contact imprint and 30% and 40% of the samples processed by the smear technique and pressure imprint, respectively, showed atypical crystal formation. On day 21, 40% of the samples processed by the touch imprint and 10% of the samples processed by the smear technique and pressure imprint showed typical crystal formation. It is concluded that the techniques of preparation of samples influence the crystallization of cervical mucus, being the most recommended, the touch imprint and pressure imprint.

Keywords

• Cervical mucus
• cervical flow
• dairy cows
• crystallization