Simple SummaryNutrition plays a key role in the epigenetic regulation of gene expression in dairy cows. Epigenetic alterations refer to the changes in gene expression that are not caused by changes in the DNA sequence itself, but rather by modifications to the DNA molecule or the proteins that interact with it. These modifications can be influenced by environmental factors such as diet and have a deep impact on the health and productivity of dairy cows. This work summarizes the main causes of nutrition that produce epigenetic changes in dairy cattle.AbstractDairy cows require a balanced diet that provides enough nutrients to support milk production, growth, and reproduction. Inadequate nutrition can lead to metabolic disorders, impaired fertility, and reduced milk yield. Recent studies have shown that nutrition can affect epigenetic modifications in dairy cows, which can impact gene expression and affect the cows’ health and productivity. One of the most important epigenetic modifications in dairy cows is DNA methylation, which involves the addition of a methyl group to the DNA molecule. Studies have shown that the methylation status of certain genes in dairy cows can be influenced by dietary factors such as the level of methionine, lysine, choline, and folate in the diet. Other important epigenetic modifications in dairy cows are histone modification and microRNAs as regulators of gene expression. Overall, these findings suggest that nutrition can have a significant impact on the epigenetic regulation of gene expression in dairy cows. By optimizing the diet of dairy cows, it may be possible to improve their health and productivity by promoting beneficial epigenetic modifications. This paper reviews the main nutrients that can cause epigenetic changes in dairy cattle by analyzing the effect of diet on milk production and its composition.