Nutrients can support the immune system by providing antioxidants. Some of the nutrients with antioxidant properties include carotenes, vitamin E, vitamin C, zinc and selenium. In addition to providing adequate amounts of vitamins and minerals and minimizing excess body condition at parturition, other opportunities may exist for augmentation of immune function.

Provisions of microbiological fractions and probiotics in the diet offer potential to support the immune system, says Neil Forsberg, vice president of OmniGen Research in Covallis, Ore. Although it is not fully clear how this works, it is possible that these feed supplements influence receptor signaling in the gastrointestinal (GI) tract.

"We have hypothesized that these products increase GI signaling via Toll-like receptor signaling," says Forsberg.

Toll-like receptors alert the immune system to the presence of microbial infections. As we learn more about signaling and control of immune function, it is likely that additional nutritional strategies will be utilized to maintain and support immune function and health, Fosberg says. In a paper presented at the Penn State Dairy Cattle Nutrition Conference, Forsberg discusses a feed additive that his company developed that may make animals less susceptible to mammary infections from E. coli, S. aureus and S. uberis.

"One potential mechanism by which the additive was able to render animals less susceptible to mammary infections was via enhancement of neutrophil function," he said.