By Aerica Bjurstrom
As calving season is in full swing, you have probably prepared your farm to provide the best possible start for your new calf crop. A new calf crop is an exciting and stressful time on a farm. Most beef producers have an expected calf mortality rate, but suffering too much mortality can be devastating to your beef enterprise.
Managing critical control points at calving can help you have a successful calving season. According to a 2008 study by National Animal Health Monitoring System and the United State Department of Agriculture, the highest calf loss is within several days after delivery, and the vast majority of losses occur during the first three to four weeks of life. Calves born dead accounted for nearly half of calf losses (44.5%) during the first six months of 2008. Another 13.5% of losses occurred in the first 24 hours following birth, and 28% of the losses occurred more than 24 hours but less than three weeks following birth. This information highlights how critical the parturition process and early post-partum period is for calf survival. Ensuring proper nutrition for dams, timely intervention during difficult calvings, and effective infectious disease control can help minimize calving losses.
There are several factors that contribute to calf mortality. Difficulty at calving is the most common reason for stillborn calves. Using calving ease sires is a long-term solution for preventing stillbirths. Another factor that increases stillbirths is interrupting labor. A cow should not be moved or interrupted from labor unless the calf's feet are present. Moving or disputing the cow too often or at the wrong time can cause her to stop labor and may suffocate the calf internally. Besides stillbirths, hypothermia, infectious agents such as calf scours, navel infection, and pneumonia all contribute to the mortality numbers.
Wet and cold calves are more prone to hypothermia. Getting these calves warmed as quickly as possible is critical for survival. Warming lamps are a useful tool for drying calves, but should not be used long-term, as you risk increased pneumonia cases by overusing a heat lamp. Rectal temperatures can indicate the level of cold stress a calf is suffering. A reading of less than 100 degrees F indicates the calf is suffering cold stress. At 94 degrees F or lower, the vital organs are cold and brain functions have been impaired. Whenever a calf has a rectal temperature of 100 degrees F or lower, it should be a priority to warm the calf as soon as possible.
Once body temperature has been maintained, provide colostrum as quickly as possible. Colostrum provides the calf with its first mechanism against infectious agents that we described above. Colostrum contains immunoglobulins that provide the first immunity and source of energy for the calf. The calf's ability to absorb immunoglobulins decrease rapidly with age, therefore it is important to get quality colostrum in the calf as soon as possible.
Reducing environmental stress and timing of colostrum intake are most important to the health of a newborn calf. Supplementing colostrum at birth can help get a calf off to a strong start, especially if its dam is a heifer or a very thin cow. Dams with low body condition scores do not produce quality colostrum and can compromise the heath of the calf long-term. It is recommended calves receive two quarts of colostrum within the first six hours of life and an additional two quarts within 12 hours.
Calving season can be successful by getting your calves off to a good start. Managing the calving process, preventing hypothermia, and getting quality colostrum into the calf as soon as possible will reduce mortalities significantly. A healthy calf at the start will wean a healthy calf in the fall.
Bjurstrom Is the Kewaunee County Extension ag agent.