The importance of delivering clean, high-quality colostrum to newborn calves shortly after birth has been well documented in research and widely publicized in the industry. Central to colostrum’s influence on calf survival and growth is the transfer of plasma immunoglobulin (Ig) from the dam to the offspring. Assessment of Ig status is the standard industry measurement to evaluate whether passive transfer of immunity has been achieved.

But Mike Van Amburgh, professor at Cornell University, advises that the value of colostrum does not begin and end with Ig. “There is a myriad of other components in colostrum that also have been shown to be beneficial to the calf,” he says. Among them are:

  • Insulin
  • Insulin-I-like growth factor-I (IGF-I)
  • Maternal leukocytes
  • Oligosaccharides
  • Growth hormone
  • Relaxin
  • Leptin; and
  • Short-chain fatty acids

Van Amburgh uses relaxin as an example of another key element that could influence “metabolic programming” and calves’ lifelong health and productivity. He points to research in pigs that shows lifetime reproductive performance is affected by relaxin intake in the first feeding of colostrum, and theorizes the same could be true for calves. “We do have research that shows failure of passive transfer can cause lower feed efficiency and delayed time to first calving,” he states. “Along with Ig, those calves likely missed out on other key colostrum components that impacted feed efficiency prior to weaning and additional effects postweaning.”

He says this theory reinforces the importance of following scrupulous sanitation protocols for harvesting, handling and administering colostrum to minimize the addition of bacteria to the digestive tract, which could otherwise interfere with the absorption of colostrum and the multiple benefits it delivers.