In the study, the level of antibodies to fasciolas in the milk of cows in the Moscow region of Russia was assessed and the relationship between their number and the productive characteristics of these animals was traced. In October 2021, a milk sample was taken from a dairy farm in the Moscow region of Russia, and the number of antibodies to Fasciola hepatica (ODRf) and Ostertagia ostertagi (ODRo) was assessed. Their level was determined using multivariate linear regression models and their relationship with economically significant indicators was traced: the amount of protein in milk, the percentage of fat in milk, and the interval between past calving. An increase in the ODRf quartile from 25% (0.412) to 75% (0.976) was associated with a decrease in the volume of milk produced per year by 0.8 kg (day of the lactation process) (p=0.002), with a decrease in fat content in milk by 0.07 % (p<0.001), with an increase in the interval between sections by 4.6 days (p=0.04) in the absence of a significant relationship with the level of protein in milk. In the case of simultaneous infection with both parasites, the effect of ODRf and ODRo on the volume of milk produced was additional, rather than synergistic.
