Epigenetic Modifications Influence Reproductive Traits in Small Ruminants

The epigenome undergoes dynamic changes shaped by the intricate interplay of genetic and environmental factors, which are crucial for individual growth and development. Recent studies suggest that factors such as nutrition, thermal stress (TS), infections, and assisted reproductive technologies (ARTs) can influence epigenetic changes in small ruminants (sheep and goats), potentially altering gene expression and affecting reproductive traits and productivity. Among these changes, DNA methylation, defined by the addition of a methyl group to the DNA molecule, is one of the most significant in small ruminants. Histone modifications and microRNAs also play critical roles as epigenetic factors that regulate gene expression. Epigenetic control profoundly affects gene expression patterns, which can be harnessed to target specific traits, including germ cell development, embryonic growth, and sperm quality in small ruminants. Additionally, studies in nutri‐epigenomics highlight the impact of maternal diet on the epigenetic modulation of metabolic balance in the offspring of sheep and goats. This review identifies the key environmental factors that trigger epigenetic modifications in small ruminants by assessing the effects of nutrition, TS, infections, and ART on reproductive traits. Epigenetic research in livestock is still limited due to a lack of recognition, insufficient funding, and a shortage of international collaboration. Therefore, understanding the epigenetic mechanisms that influence ruminant reproductive traits is essential for enhancing their management and performance.