Association of changes among body condition score during the transition period with NEFA and BHBA concentrations, milk production, fertility, and health of Holstein cows

Our objective was to evaluate the association between body condition score (BCS) change during the transition period with fertility, non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) concentrations, milk yield, and health problems of Holstein cows in a retrospective cohort study. Holstein cows (n = 232) were assessed for BCS (5 point scale; 0.25 point increments) and had blood collected at 21 and 7 d before, on the day of, and 7 and 21 d after calving. Blood samples were assayed for NEFA and BHBA concentrations. All cows received a timed artificial insemination (TAI) at 65 ± 3 days in milk (DIM) following a Presynch-Ovsynch protocol with a progesterone implant during the Ovsynch protocol. Cows were grouped based on BCS change after calving as to whether they: 1) lost (L), 2) maintained (M), or 3) gained (G) BCS. Data were analyzed by logistic regression with GLIMMIX and ANOVA with repeated measures using the MIXED procedures of SAS. Both NEFA and BHBA concentrations after calving differed (P