[Chemical contamination of the cervical mucus in cows in relation to pregnancy and age factors].

Applying the method of absorption atom spectrometry (AAS), the contamination of cervical mucus by chemical elements (Cd, Pb, Hg, Cr, Cu, Zn) was demonstrated in the oestrus period of cows in different ecological agricultural regions of the North Moravian region. The results of observation revealed only a statistically significant difference (P less than 0.05) in Cd contents in the test groups; test group mean = 0.015 micrograms.g-1 Cd, control group mean = 0.006 micrograms.g-1. Cr findings in cervical mucus are of priority importance, the same applies to Cu findings. Zinc was found to be an element influencing negatively the conception of cows. The Zn values in cervical mucus of nonpregnant cows were demonstrated to be significantly higher (P less than 0.01) (conception--group = 0.841 micrograms.g-1, conception + group = 0.219 micrograms.g-1 Zn. So called sum of chemical elements: Cd + Pb + Hg + Cr + Cu + Zn was proposed and evaluated as a picture of the total contamination of cervical mucus. This characteristic was also influenced by the Zn findings in the group of pregnant and nonpregnant cows. Zn: Cd antagonism in cervical secretions of barren and pregnant cows was statistically highly significant (P less than 0.01). Chemical elements in cervical mucus were determined for the first time in a digested sample of cervical secretion. The correlation coefficients used for the cows (n = 99) from a contaminated region showed that the content of chemical elements in cervical secretion was not influenced by the age of cows. The content of chemical elements in cervical secretion was not increasing with the age.