title: Effect of intrauterine antibiotic treatment on reproductive performance of dairy cows following periparturient disease.
abstract: OBJECTIVE
  To quantify the effect of treating lactating dairy cows that had histories of periparturient disorders or disease with a single intrauterine infusion of 0.5 g cephapirin, 3-6 weeks prior to the start of the seasonal breeding period.
  
  
  METHODS
  Cows (n=690) from spring-calving dairy herds (n=22) were enrolled in a prospective case-control study if they had a history of dystocia, a dead calf at calving or within 24 h of calving, retained foetal membranes (RFM), metabolic disease, twins or a vulval discharge 13 days postpartum. Cows were blocked by age, periparturient condition and calving date, and randomly assigned to be either treated with 0.5 g of cephapirin by intrauterine infusion, or left as untreated controls. Treatment occurred 24-42 days before the planned start of mating (PSM) within each herd. In addition, the reproductive tracts of 91 cows from 4 herds were examined using a vaginal speculum and rectal palpation and cervical-os discharge was scored on a scale from 0 (nil) to 3 (purulent).
  
  
  RESULTS
  Overall, more treated cows were retained in the trial herds until pregnancy testing than control cows (p0.05). Average 28-day submission rate was higher (93.1% vs 87.1%; p0.05) and PSM-to-first-service interval was shorter (9+/-1 vs 11+/-1 days; p0.05) in treated than control cows. The percentage of cows not pregnant at the end of the mating period was not affected by treatment overall. However, amongst cows diagnosed with RFM, a dead calf, or vulval discharge, pregnancy rates 28 and 56 days after PSM were higher for treated than control cows (p0.05). Cows with a purulent cervical-os discharge had lower 28-day submission rates (p0.01), lower 28-day pregnancy rates (p0.05) and higher non-pregnant rates at the end of mating than cows with nil or mucoid cervical-os discharges.
  
  
  CONCLUSIONS
  Intrauterine treatment with 0.5 g cephapirin improved reproductive performance of dairy cattle, especially those that had a history of RFM, a calf dead at calving or within 24 h of calving, or a vulval discharge.
authors: Animal Health Centre, PO Box 21, Morrinsville, New Zealand. McDoug@anhealthc.co.nz
authors: S
authors: S
authors: McDougall