A newborn calf comes into the world with a bright future ahead . . . and an incomplete immune system. The antibodies absorbed through colostrum serve as a raft to keep calves afloat until their own immunity develops. But is colostrum alone enough?
"A calf is in a bit of a ‘catch-22' situation early in life," said Michael Ballou, Texas Tech University, during his presentation at the American Association of Bovine Practitioners (AABP) annual meeting. He explained that the same holes in the gut that allow passive absorption of macromolecules from colostrum also elevate the risk for translocation of disease-causing microorganisms.
Ballou said we still have a lot to learn when it comes to understanding the development of the gastrointestinal (GI) tract of a calf. We can, however, use gastrointestinal morbidity and mortality risk as an indirect measurement.
"The risk of mortality greatly decreases after the first few weeks of life," Ballou said. Therefore, researchers believe that maturation occurs quite rapidly during the first few weeks after birth.
There are many components to the GI immune system - physical, chemical, immunological and microbial - and some parts are still developing after birth. These barriers work together to create a competent immune system of the gastrointestinal system. A defect in any one of these components, though, can raise the risk of infectious disease.
Ballou described the ideal situation, where there would be the absorption of adequate antibodies, with no absorption of microorganisms and rapid maturation of the GI tract. "But we don't have an ideal situation in most situations," he said.
Beyond colostrum, what else can be done? Ballou touched on nutritional strategies, including prebiotics, probiotics and a higher plane of nutrition, as potential ways to help speed up the maturation process and prevent GI disease. More research will continue in this area to help fill the holes in our understanding of the holes in calfhood immunity.
(c) Hoard's Dairyman Intel 2015
October 12, 2015
