<![CDATA[This study aimed to determine ultrasound of uterine involution and postpartum ovarian dynamics on Ongole Crossbreed Heifer (PO) associated with postpartum estrus signs. This study used 6 PO cows which were divided into primiparous group and pluripara group. The observation of uterine involution and ovarian dynamics was started from the first day postpartum using ultrasonography (USG) with a linear probe rectally, while the reproductive organs images were recorded every 2 days. The results showed that the time needed for all reproductive organs of 3 primiparous groups to complete the uterine involution after parturition was 37.33±1.15 days when the diameter of the vagina, cervix uterine, corpus uterine, left cornua, and right cornua uterine were 3.14±0.00 cm, 2.86±0.00 cm, 3.20±0.06 cm, 4.66±0.01 cm, and 4.66±0.01 cm, respectively. The time needed for all reproductive organs of 3 pluripara groups to complete uterine involution postpartum was 38.67±1.15 days with the diameter of the vagina, cervix uterine, corpus uterine, left cornua, and right cornua uterine 3.18±0.00 cm, 2.70±0.02 cm, 3.08±0.02 cm, 4.42±0.01 cm, and 4.42±0.01 cm, respectively. The average times of the first and second ovulation of primiparous cattle were 27.67±1.15 and 47.67±1.15 days postpartum, whereas in pluripara group was 28.33±1.15 and 48.33±1.15 days postpartum. At first ovulation all cows were not accompanied by signs of estrus, while at the second ovulation 2 primiparous cows and 1 pluripara cow showed less obvious signs of estrus, 1 primiparous cow and 1 pluripara cow showed signs of medium estrus, and 1 pluripara cow showed clear estrus signs.]]>
