Written by Dr. Megan Van Emon, Extension Beef Cattle Specialist
Newborn calves that present weak calf syndrome are those that are not able or are slow to rise, stand, or nurse. Calves born in this condition will often die within a few days after birth. There may be several possible reasons for weak calf syndrome. Factors that may cause weak calf syndrome are bad weather, selenium deficiency, poor nutrition during late gestation, dystocia, cow age, and other trauma to the calf. Weak calves must be treated or helped immediately after birth to improve their chances of survival.
Due to the atypical winter and spring, we have experienced in Montana, this may be a leading factor in weak calf syndrome this calving season. Extreme cold and snow conditions may have caused stress to cows during gestation, which directly impacts cow immunity. The additional stress of temperature variability in the past couple of months may have also played a role in increasing the odds of weak calf syndrome. Providing sheltered areas to minimize the impacts of the extreme conditions may help in reducing the incidence of weak calf syndrome.
Cow nutrition also plays a large role in weak calf syndrome. If cows were maintained on a low plane of nutrition, this could cause an increase in the incidence of weak calf syndrome in your herd. Cows consuming a low protein (less than 10% CP) diet during the last 60 days before calving have been shown to have a greater incidence of weak calves at birth. Additionally, a low energy diet during the last 60 days prior to calving can also increase the occurrence of weak calves. Therefore, providing a good quality diet in the last 60 days prior to calving is crucial to minimizing weak calf syndrome in your herd.
Dystocia and other trauma to the calf also have the potential to cause weak calf syndrome. The stress of the trauma can negatively impact calf immunity. The additional stress can cause the calf to become hypoxic (low oxygen levels), which may cause neonatal acidosis. If neonatal acidosis occurs, calves that do suckle are unable to absorb the needed antibodies from the colostrum. The lack of antibodies from the cow’s colostrum may lead to additional illness as the calves age.
Selenium deficiency causes white muscle disease. If cows are selenium deficient during gestation, calves may be born with weak muscles, which includes a weak heart, which may lead to the death of the calf soon after birth.
Very old cows and first-calf heifers may be more likely to have weak calves. Usually, nutrition is the main factor causing weak calf syndrome in these two age groups. Heifers require additional nutrients because they are still growing when calving for the first time and older cows may have a harder time in maintaining the extra body weight needed for calving.
Calves should nurse within an hour after birth to absorb the needed maternal antibodies from colostrum. If a calf is born weak, the calf will need help to suckle and may require additional help to keep warm. If a calf is dehydrated at birth, electrolytes and warm fluids may be required to help the calf rehydrate. Presenting weak calves to your veterinarian may aid in determining the underlying cause and a plan may be prepared to minimize the occurrence of weak calves in the future.
Dr. Megan Van Emon is the Extension Beef Cattle Specialist at Montana State University (MSU).