Background
Systems physiology is a scientific discipline combining theoretical, computational, and experimental studies to increase our understanding of the physiology of living creatures [1]. Understanding organism biology requires a systems physiology approach to dissect molecular and cellular mechanisms that regulate phenotypes, develop- ment and disease of cattle. Homeostasis is essential for cattle to achieve and sustain health and, indirectly, food productions and requires hormones, powerful substances secreted by various organs in the body responsible for stimulating a cell-specific response. Stress is defined as a condition in an animal that results from the action of one or more stressors of either external or internal origin. Adjusting to stress induces a wide range of behavioral and physiological responses including endocrine changes in the hypothalamus-pituitary-adrenal (HPA) axis thus re- leasing corticosteroids and aldosterone [2]. The overall effects on the animal are multifaceted,