Transition cow metabolites and physical traits influence days to first postpartum ovulation in dairy cows

Physical activities are associated with the health of transition dairy cows and pregnancy outcomes positively related to early resumption postpartum estrous cycles. The objective was assess key metabolites patterns prepartum physical activity as they relate onset first ovulation in lactating cows. Close-up dry Holstein (n = 82) late gestation heifers 78) were enrolled beginning 3 wk before expected calving date (Day 0). Cows fit Cow SensOor ear tags transitional changes eating, resting, rumination, high activity, ear-surface temperatures. Rectal temperatures assessed blood samples collected on Days 0, 3, 7, 14 measure concentrations glucose, free fatty acids (FFA), β-hydroxybutyrate (BHB), calcium, haptoglobin. Body condition scores (BCS) body weights (BW) measured weekly, weekly from Day 21 ± through 70 quantify progesterone detect luteal function after ovulation. ovulating median 33 classified 76), whereas those 84). Early ovulated earlier (P < 0.001) than (24.3 1.2 d [range: 16–32 d] vs. 48.8 33–74 d]), respectively. Mean days excluded seven that failed ovulate insemination. Compared cows, had lesser 0.05) FFA, BHB, haptoglobin addition having rectal Ear-surface began decrease 4 parturition remained less subsequently late. tended 0.07) spend more time 0.02) resting being active during calving, lost 0.03) BW BCS 9 compared Although no differences detected yields milk or energy-corrected produced 0.01) protein. We concluded metabolic measures 2 behavioral traits ovarian activity.