Effect of systemic antibacterial administration during prepartum period on coagulase negative Staphylococcal intramammary infection in Holstein Heifers

A total of 183 coagulase negative Staphylococcal infected quarters and 64 uninfected quarters were randomly allotted to 4 experimental groups: infected quarters that did not receive any treatment (positive control group; n = 60); infected quarters that received Tylosin (n = 61) or Cefquinome (n = 62) and also uninfected quarters that did not receive any treatment were considered as negative control group (n = 64). Treated heifers received Tylosin or Cefquinome 10 to 14 days before the expected calving date. The bacteriological cure rate based on sampling obtained 3 days after calving was significantly higher (P<0.01) in mammary glands treated with systemic Tylosin (85.3%) than in the positive control group and mammary glands treated with systemic Cefquinome (69.4%). At the same time Tylosin treated heifers had significantly lower (P<0.01) somatic cell count scores compared to the positive control and Cefquinome groups. With the exception of one heifer that calved 8 days earlier than the expected calving date, there was no detectable antibiotic residues in the milk of the treated heifers on the 3rd day of lactation.