The Physical Signs of a Heifer's Pregnancy

Pregnant heifers require specific care regarding adequate feeding, housing, isolation and monitoring. Whether your heifer has been bred with a bull or inseminated artificially, an accurate diagnosis of pregnancy is essential in maintaining the health and well-being of both mother and calf. Though advanced technologies such as ultrasounds or hormone measurements can be used to accurately determine pregnancy, several physical signs also indicate a successful breeding cycle.

  1. Suspension of Oestrus

    • An unfertilized heifer will enter regular cycles of oestrus or heat to signal that she is prepared for reproduction. For dairy cows, oestrus cycles typically occur every 21 to 23 days. During oestrus, increased levels of estrogen cause the heifer's behavior to change. Normal signs of oestrus include swelling and reddening of the vulva, restlessness, slowed milk production and presenting mounting positions. If a heifer does not present these signs during an expected period of oestrus, then it is likely that the heifer is pregnant.

    Changes in Reproductive Organs

    • One of the most common means of diagnosing a heifer pregnancy is through a rectal palpation in which a trained veterinarian or farmer manually inspects the interior of the heifer's reproductive system through the anus. A rectal palpation can reveal many symptoms of pregnancy. During the early stages of pregnancy, a heifer's uterine horns will differ in size due to the imbalance of fluid created during pregnancy. The fetal membrane inside the uterus may slip during an examination, a significant indicator of pregnancy. At later stages in pregnancy, the fetus can be felt within the uterus during a rectal palpation.

    Milk Production

    • One of the first signs of heifer pregnancy is a decrease in milk production. According to the USDA National Agricultural Statistics Service, a healthy dairy cow can produce anywhere between 1600 lbs. to 1900 lbs. of milk per month. A pregnant heifer, however, will show a sudden decrease in her average milk production as a result of a pregnancy. For accurate determination of a pregnancy, a heifer's milk production should be recorded, and comparisons should only be made to the heifer's previous milk production. A rectal palpation can rule out other reasons for decreased milk production, including illness.