F.N.S. Pereira, E.B. de Oliveira, V.R. Merenda, F.S. Lima, R.C. Chebel, K.N. Galvão, J.E.P. Santos, R.S. Bisinotto, and C.C. Figueiredo. 2026.
Abstract: The objectives of this study were to assess differences in lactational performance (reproduction, milk production, and removal from the herd) associated with time to clinical cure of metritis. This retrospective cohort study was conducted using data from 3 experiments conducted at 5 dairy herds in Florida. Cows with metritis were randomly assigned to receive either ampicillin or ceftiofur in 2 experiments (1 experiment only implemented ceftiofur). Vaginal discharge assessment using the Metricheck device within 12 DIM was used to diagnose metritis, characterized by presence of fetid, watery, reddish-brown vaginal discharge (VD; n = 1,410), and the day of diagnosis was defined as d 0. A total of 556 cows were treated with ampicillin, and 854 cows were treated with ceftiofur. Clinical cure was visually assessed on d 5 and 12 and defined as clear, mucopurulent, or purulent VD. Cows were grouped as follows: CureD5 (cured by d 5; n = 705); CureD12 (cured between d 6 and 12; n = 406); NoCure (not cured by d 12; n = 299); NoMet (not diagnosed with metritis; n = 1,194). Data regarding risk of receiving a first service, risk and hazard of pregnancy by 300 DIM, risk and hazard of removal from the herd by 300 DIM, and total milk production within 10 mo were collected from the herd management software. Statistical analyses were performed using multivariable logistic regression, Cox proportional hazards, and ANOVA models. Orthogonal contrasts were set to assess the effects of metritis, clinical cure, and time to clinical cure. The antimicrobial treatment formulation was not associated with the odds of cure by d 5. A greater proportion of CureD5 cows received a first service (91.6% vs. 87.1%) and were pregnant by 300 DIM (69.6% vs. 62.9%) compared with CureD12 cows. However, time to cure was not associated with reduced hazard of pregnancy within 300 DIM. A smaller proportion of CureD5 cows were removed from the herd by 300 DIM compared with CureD12 cows (15.5% vs. 23.7%). Additionally, a smaller hazard of removal from the herd within 300 DIM was observed for CureD5 compared with CureD12 cows (0.61). No differences in milk production within 10 mo were associated with time to clinical cure. Our findings highlight that expedited clinical cure of metritis was associated with positive effects on reproductive performance and removal from the herd.