The Calves are Coming!
Properly caring for your calves
Most commercial beef cows in the United States are spring calvers. As the grass starts turning green (and even before), calves start to hit the ground. A quick review of the basics can help assure a successful calving season.
Cows should be managed to calve annually. After calving, cows need to be rebred and conceive within about 80 days in order to stay on an annual calving schedule. Cows in poor body condition lack the energy reserves necessary to support lactation and conception simultaneously. As a result, the interval between calves is often prolonged in thin cows. Reproductive performance is best in cows with a Body Condition Score (BCS) of 5 to 6 (on a 9-point scale).
Heifers require special management. In addition to maintenance requirements, these young females are still growing during their first pregnancy and must be fed appropriately to support this growth. To calve as a two-year-old, a heifer must be bred by 15 months of age. Heifers should be approximately 65% of their mature body weight (715 pounds for cows with a mature weight of 1,100 pounds) when first bred. Heifers should typically be fed to gain 1 to 1½ pounds per day during their first gestation. They should weigh approximately 85% of their mature weight (935 pounds, excluding the weight of the calf and associated tissues, for cows with a mature weight of 1,100 pounds) at calving.
The average length of gestation term in cows is 283 days. As calving approaches, observation of pregnant females is important. This is especially true with heifers. Calving is commonly divided into three stages: preparatory; delivery; and cleaning. The preparatory stage usually lasts two to six hours. During this stage, the calf rotates into the proper position, the cervix begins dilation, and uterine contractions begin. The water sac is expelled toward the end of the preparatory stage.
The delivery stage usually takes one to two hours. Cows lie down, the cervix fully dilates, and uterine contractions become more frequent and intense. Most females that have been managed properly will calve without assistance. However, it is important to know when to take a closer look. A good rule of thumb is to evaluate the situation if the cow or heifer has made no progress after 30 minutes. Dystocia, or calving difficulty, can be caused by several things, including: inadequate physical development of the dam; small pelvic area in the dam; excessive body condition of the dam; calf size; multiple calves; and improper positioning of the calf. Timely intervention by a veterinarian and (or) experienced herdsman will increase the likelihood of a good outcome.
Cleaning, the third and final stage of pregnancy, will usually occur within two to eight hours after delivery. In this stage, the attachments between the uterus and placenta relax and the membranes are expelled. If the cow does not clean, a veterinarian should be consulted for treatment options. Note that fetal membranes should never be removed manually.
Good calving!
By: Dr. Rob McCoy
References:: Assisting the Beef Cow at Calving Time,
J. Whittier and J. Thorne, University Extension,
University of Missouri-Columbia
How to Save More Calves at Calving,
R. Mortimer, Beef Today and Elanco Animal Health
