Table 2.

Antimicrobials administered directly and indirectly to cohort animals

FarmAntimicrobial administered
Coccidiostata or wormerLasalocidbNeomycin sulfatecPenicillindSulfonamideeMedicated feedfOthersh
HNoYes (275 g/ton)NoYesNoYesNo
RYesYes (1,400 g/ton)YesYesYesYesYes
XYesYes (57 g/ton)NoYesYesNogNo
  • a Decoquinate, ivermectin, and morantel tartrate were used.

  • b Lasalocid was present in feed.

  • c On farm R, neomycin sulfate was administered orally twice each day in milk fed to calves from birth through 6 weeks of age. In addition, from 6 to 12 weeks of age, neomycin sulfate was added to animal drinking water.

  • d Penicillin was received indirectly through milk from treated cows.

  • e Oral boluses of sulfamethazine were given on farm R and farm X as needed for diarrhea.

  • f Farms C, H, and R used feed containing chlortetracycline (4,000 g/ton) and sulfamethazine (4,000 g/ton). Farm H periodically used feed with oxytetracycline (126 g/ton) and neomycin sulfate (250 g/ton).

  • g The only medication in feed on farm X was morantel tartrate (dewormer; 8,800 g/ton).

  • h Injectable antibiotics were administered to animals with clinical upper respiratory disease.