Nutritional application of olive pomace in dairy animals: chemical composition, implications for milk quality and yield, nutrient digestibility, economics, and limitations

<p>The olive oil industry produces large volumes of by-products which, if not properly managed, can negatively impact water resources, aquatic ecosystems, soil quality, and the atmosphere. The extraction process generates several by-products that have previously been regarded as waste. Utilizing these residues as alternative feed ingredients aligns with the principles of a circular economy, making the agri-food system more sustainable, conserving natural resources, and reducing the environmental footprint of livestock production. Therefore, the proper use of industrial by-products is of great importance and requires continuous attention. Olive pomace, a major by-product of olive oil extraction, can be used in animal feed as an inexpensive yet nutritious residue. It consists mainly of pasty pulp, kernel, skin, and vegetation water. Once dried, it becomes a stable by-product suitable for feed use. Olive by-products can be incorporated into animal diets in several forms, such as fresh, ensiled, or dried material, or as components of concentrate pellets and multi-nutrient feed blocks. Among these, dried olive pomace is considered one of the most practical and stable options. Olive pomace, as a by-product of the olive oil industry, is rich in phenolic compounds and beneficial fatty acids that play significant roles in animal health and productivity. Hence, it is crucial to evaluate its potential as a feed ingredient; however, current understanding of its specific effects on livestock production remains limited. This review focuses on the influence of olive pomace inclusion in animal diets on milk production, growth performance, nutrient digestibility, feed efficiency, and overall health status. In general, dietary olive pomace has shown satisfactory results, serving as a low-cost nutrient source that can enhance both the productivity and the quality of animal-derived products.</p>