ARTICLE FEED & ADDITIVE MAGAZINE May 2025 73 “Epigenetic activation begins within the first few days of life. Calves receiving insufficient colostrum or nutritional restriction during critical developmental periods typically underperform later in life. Colostrum provides essential nutrients and bioactive factors for positive epigenetic programming. Inadequate colostrum intake or early-life nutritional deficiencies can alter DNA methylation, histone modifications, and gene expression, impairing metabolism and immunity, increasing susceptibility to disease, and adversely affecting adult productivity.” Ruminant nutritionists traditionally focus on fulfilling nutrient requirements to support growth, lactation, and reproduction. Contemporary nutritional science, however, reveals a deeper role for nutrients beyond simply serving as substrates, they directly influence gene expression. This nutrient-driven modulation, termed epigenetics, significantly affects immunity, health, and longevity in dairy cows. Epigenetics (Greek: epi-, meaning "above," and genetics, meaning "origin") refers to mechanisms regulating gene activity without changing the underlying DNA sequence. Simply put, epigenetics acts like switches, turning genes on or off based on nutrient-derived metabolites. When these metabolites are abundant, beneficial genetic pathways activate; when scarce or imbalanced, critical pathways may become inactive, compromising health and longevity. In this article, I explore practical ways to activate the genetic switches of epigenetics—simple strategies to help turn on beneficial genes through strategic feeding. EPIGENETIC MECHANISMS EXPLAINED Primary epigenetic mechanisms include DNA methylation, histone modifications, and non-coding RNA regulation. Adding methyl groups to DNA sites (CpG islands), typically silences gene expression. Histones, small proteins forming nucleosomes around which DNA wraps, can undergo acetylation, methylation, and phosphorylation. These modifications alter DNA packaging: Tightly wrapped DNA suppresses genes, while loosely wrapped DNA allows gene expression. Non-coding RNAs further influence gene interpretation. These epigenetic modifications are heritable and responsive to dietary conditions (Figure 1). NUTRITIONAL IMPACTS ON EPIGENETICS Specific nutrients, including methionine, choline, folic acid, vitamin B12, and minerals like zinc and selenium—are essential for epigenetic processes. DNA EPIGENETICS AND IMMUNITY, HEALTH, AND LONGEVITY IN DAIRY COWS Dr. Alvaro Garcia, DVM Feeds Specialist and Nutritionist Dellait Animal Nutrition and Health
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