Fig 1. Schematic representation of experimental protocol showing the period of adaptation (7 days), 96 days of feeding (CON vs. RPM), the reproductive protocol used, and each measurement taken throughout the experiment.
The Double Ovsynch protocol was used to synchronize ovulation in all cows and timed AI was performed on Day 65 ± 3. Pregnancy diagnosis (PG) were performed on Days 32, 47, and 61 after AI. RPM feeding started on Day 30 ± 3 and continued until a cow was diagnosed not pregnant on Day 32 or until Day 61 after AI. Blood samples were collected on Day of last PGF2α and GnRH and on Day 5 and 28 after AI to analyze progesterone (P4) concentrations, on the week of AI and first PG to analyze AA concentrations, and on Day 28 after AI to analyze Pregnancy specific-protein B (PSPB) concentrations. Ultrasound videos were made on Day 33 after AI to evaluate embryonic and amniotic vesicle size. Milk tests were performed at (58 ± 9; mean ± SD), 73 to 100 (87 ± 9), and 101 to 128 (115 ± 9) DIM.