Providing proper nutrition and minimizing stress can improve a cow’s ability to fight disease.
While good animal husbandry is not very sexy and some people overlook it in their ongoing search for a “silver bullet,” it is vitally important, points out Amelia Woolums, professor of large animal internal medicine at the University of Georgia.
“Nutritional deficiency and prolonged stress have both been shown to impair (the cow’s) innate immune functions as well as adaptive immune functions,” so preventing these problems is important to support immune response, she says.
Enhanced immunity is a collective effort between you and the cow, and that includes judicious use of nutritional supplements and animal health products.
“In the absence of proper nutrition, the immune system will not perform optimally,” says Marcus Kehrli, Jr., veterinary medical officer at the National Animal Disease Center in Ames, Iowa.
“However, very little research has been done to define basic nutritional requirements of cattle to support immune function; especially lacking is science defining the nutrient requirements of transition cows,” he says.
The transition cow is faced with numerous challenges. For example, hypocalcemia during the transition period has been associated with depressed neutrophil (immune cell) function.
Epidemiological data going back decades have identified greater disease incidence in transition cows that experience ketosis and/or milk fever. “Given the immune system requires a wide array of nutrients… it only makes common sense that if we short-change the transition cow nutritionally, it will only further enhance her susceptibility to a myriad of infectious diseases, particularly in the first few weeks of lactation,” Kehrli says.
Some believe that supplementing nutrients, such as vitamins or minerals, in excess can improve response.
Yet, numerous studies have looked at the impact of various nutrients and feed supplements on immune response, Woolums says, and the bottom line is that nutrient supplementation in excess of maintenance requirements generally does not improve immunity, although there are specific examples of certain vitamins or minerals associated with improved immunity. For example, vitamin E and selenium have been shown to help defend against mastitis.
It’s important to have the animals as stress-free as possible, since stress releases cortisol which can interfere with immunity.