Nutritional Consideration of the Immune System

Abstract

The immune response is mediated by both specific and nonspecific effector mechanisms interacting with invading agents or antigens. Nonspecific conponents include phagocytic cells such as neutrophils, monocytes, and macrophages. In contrast to the nonspecific elements of the immune system, which are capable of interacting with a broad array of antigens, some components, such as T cells, are specific in their recognition of antigens. The concept of vaccination against infectious diseases is based on these principles of immunological specificity and memory.

Cattle are exposed to a variety of stressors that stimulate non-specific and specific responses that develop either a natural resistance or an acquired resistance.

Many factors affect the responsiveness of the immune system. It has been well established that protein and energy malnutrition severely depresses the immune system. However, in recent years, the effects of trace minerals on the immune system has been documented. The trace minerals, zinc (Zn), copper (Cu), selenium (Se) and iron (Fe), have been demonstrated to be involved in immunocopetence. Vitamin E has been documented to effect the immune system.

The exact mechanism of immune depression with Zn deficiency is not know. However, many factors during BRD could lead to Zn deficiency and decreased immune response.

Serum Cu increases during infection. However, if Cu deficiency exists and inadequate liver storage exists, an impaired immune response can result.

Other trace minerals such as Fe and Se are involved in immunity responses in cattle. Iron deficiency anemia is associated with impaired cell-mediated immunity.

Trace minerals in deficiencies and in excesses can affect the immune system of cattle. The importance of trace minerals in nutrition of cattle is well known. The effects of trace minerals on immunity has been established, but specific levels and action have not been completely documented.

A discussion of the interaction of nutrients and the immune system with recommendation of nutrient levels to aid the immune system during receiving and processing is discussed.