EN
The objective of the studies was the evaluation of dynamics of disappearance of residues of chloroorganic pesticides in the mammary gland secretion of cows during the perinatal period. Chloroorganic compounds were determined by the gas chromatography in materials collected from 12 cows prior to parturition, during colostral period and on the day 14 after parturition. Significantly higher concentration of the HCH isomers as well as DDE+DDT+DDD were observed in the secretion of udder prior to parturition as compared to the concentration of these compounds in colostrum and in milk. The concentration of the HCH isomers was higher than other compounds in all the samples. Considerable differences were observed in the content and frequency of particular compounds in the samples from different periods of lactation.