Colostrum Consumption Impacts Calf Immunity
Colostrum counts. From energy and nutrients to maternal antibodies that provide passive immunity to newborn calves, colostrum intake can have life-long effects on the calf’s health. But proper colostrum production begins by first making sure cows and heifers receive adequate nutrition and immunization prior to calving.
According to researchers at Ohio State University, inadequate passive immunity can increase the likelihood of illness and death, as well as negatively impact growth performance in the feedlot.
The first seven days of a calf’s life can be critical to a cow-calf herd. Seventy percent of the pre-weaning deaths occur within the first seven days after birth in beef herds. The causes of these deaths can include low birth weights, cold weather, difficult births, and poor immunity. Genetics can influence calving difficulty and birth weights, so selecting bulls for calving ease is one step. Additionally, late-gestation nutrition can be critical, and the goals are to keep cows in adequate body condition, while not having cows too fat or too thin. A study at Louisiana State University, observed the lowest percentage of calving difficulty in heifers with a body condition score (BCS) between 5 and 6, whereas heifers with BCS 4 had lighter birth weight calves with greater calving difficulty. Weak calves due to difficult births and exposure to cold and wind can reduce the calf’s desire to get up a nurse.
In addition, the first 24 to 72 hours are critical for immunity of the calf. Calves need colostrum, which contains not only energy and nutrients, but also maternal antibodies, which provide immunity to the calf. The transfer of passive immunity through colostrum can have life-long implications. A study by Wittum and Perino at The Ohio State University investigated the long-term effects of inadequate passive immunity of the calf at birth. This study found if calf blood levels of immunoglobulin (IgG) were less than 800 mg/dL, those calves were 3 to 9 times more likely to become sick and 5 times more likely to die prior to weaning. In addition those calves averaged 35 pounds less in weaning weight and had a greater incidence of illness and death as well as lower growth performance in the feedlot.
The calf’s blood IgG levels are influenced by two things 1) the amount of maternal antibodies produced by the cow in the colostrum and 2) the ability of the calf to nurse and absorb the antibodies. Selecting cows for good maternal instincts, temperament, and udder conformation are important considerations. Again, providing adequate nutrition to the cow/heifer prior to calving to supply sufficient energy and protein is critical to production of colostrum. This can also contribute to proper fetal development and growth, which can impact the calf’s vigor and health shortly after birth and the calf’s ability to absorb those antibodies. If a farmer provides good nutrition, management, and protection from weather, the calf should get up a nurse several times during the first 12 hours. In addition, a vaccination program for the females in the herd uses the cow’s immune system to provide antibodies to the calf by colostrum, so consult a veterinarian for appropriate vaccination protocol.
If calves do not get up a nurse early or are weak, a farmer has several options to help provide passive immune transfer. The best alternative is the ‘real thing’, by either milking the calf’s dam or using frozen colostrum saved from another cow in the herd. If using frozen colostrum, thaw at room temperature or in warm water, but not in the microwave as antibodies can be denatured at higher temperatures and are then ineffective in establishing immunity. Although commercial powdered replacements are not as ideal as colostrum, they can be used as an alternative. If whole milk or electrolytes is fed first before the colostrum, this can reduce the absorption of the antibodies by the calf and is not recommended. In addition, the colostrum should be delivered through a nipple and not a drench tube, because this can tend to improve absorption by the calf. A calf should receive 5 to 6 percent of its body weight in colostrum within the first six hours of life.
The first few days are important to the lifetime health and performance of the calf, so farmers should pay close attention to make sure calves are nursing and receiving adequate colostrum. Furthermore, proper nutrition, vaccination, and management prior to calving are good strategies to improve the first week of the calf’s life as well as for his or her lifetime.
