ISSUE FOCUS FEED & ADDITIVE MAGAZINE November 2025 61 From calving stress to oxidative stress, other factors converge to activate the immune system and divert energy from milk production. First of all, the increased metabolic demand, along with the demands of the developing calf, can lead to an elevated production of reactive oxygen species (ROS) as byproducts of metabolism. A disruption in the balance between ROS and antioxidants is the definition of oxidative stress, which can also contribute to inflammation and immune dysregulation. Moreover, stress, common around calving, activates the hypothalamic pituitary-adrenal axis, leading to the release of corticotropin-releasing factor (CRF), which can disrupt the intestinal barrier and contribute to systemic inflammation. The increased energy demand of the immune system causes the animal to shift its metabolic priorities, negatively affecting growth, reproduction and productivity. THE TRUE COST OF INFLAMMATION Inflammation redirects energy from milk synthesis to immune defense — costing up to 26 kg of milk every day! During immune activation associated with increased intestinal barrier permeability, metabolism normally dedicated to milk synthesis, that normally requires 25-30% of basal metabolism in a healthy animal, is redirected towards the immune system. The immune system requires a great deal of energy. Once under pressure, this requirement increases, which consumes nutrients. The cow will find energy sources including glucose as precursor of lactose, which are intermediaries as the cow mobilizes fat stores as a source of energy. If the inflammation becomes pathological, it reduces feed intake and may result in metabolic syndromes such as hypocalcemia. The use of glucose by the immune system and the reduction in feed intake are responsible for the increase in NEFA (non-esterified fatty acids) and ketones, explaining a decline in overall health, production, and reproduction outcomes. Recent studies show that the energy to fight against inflammation (modeled by LPS-induced infection) costs the equivalent of 2 kg of sugar every day and approximately 26 kg of milk loss. POST-PARTUM DISORDERS: INFLAMMATION’S RIPPLE EFFECT Inflammation can also cause post-partum disorders in dairy cows, such as ketosis, milk fever (hypocalcemia), reproductive tract infections such as retained fetal membranes, metritis, and endometritis. All of these can negatively impact the cow's health, fertility, and milk production. For example, ketosis, which occurs when the cow mobilizes excessive fat for energy, leads to an accumulation of ketone bodies, resulting in a decrease in milk quality and fertility. Research shows that inflammation during the transition period negatively
RkJQdWJsaXNoZXIy MTUxNjkxNQ==