Influence of milking frequency on withdrawal period after application of β-lactam antibiotic-based drugs Original Research Article

Different milking frequencies observed with cows milked with automatic milking systems (AMS) may influence the excretion of veterinary drugs in milk of treated cows. Experiments (4–5 cows per experimental group) with two β-lactam antibiotic-based drugs—cefquinome and penicillin—and different milking intervals—3, 2 and 1.5 times per day—made it clear that, in the case of cefquinome, the influence of individual cows was more pronounced than that of milking frequency whereas in the case of penicillin the time necessary to fall short of the maximum residue limit (MRL) increased with decreased milking frequency. The withholding time for penicillin differed significantly between milking frequencies of 3 and 1.5 times per day.