Olive Waste as Feed Supplement: Morphometrical Effects on the <i>Ansa spiralis coli</i> in Lambs

Feedlot systems for small ruminants require nutritionally adequate and viable diets, and the incorporation of olive residues can offer a sustainable and economically advantageous alternative. This study evaluated the effects of including olive waste at 7.5%, 15%, 22.5% and 30% in the diets of Texel × Ile-de-France lambs, assessing the architecture and structure of the Ansa spiralis coli through gross anatomy, morphometry and light microscopy using ImageJ software (Fiji). Diets with up to 22.5% olive residue did not modify the morphology or morphometric parameters of the Ansa spiralis coli, with all specimens exhibiting three centripetal and three-and-a-half centrifugal gyri and a mean length ratio of 1.18; however, the 30% inclusion level significantly increased the thickness of the tunica muscularis, suggesting potential effects on intestinal motility. These findings indicate that up to 22.5% olive residue can be safely incorporated into lamb feed as a sustainable and economically viable option, helping bridge knowledge gaps on olive byproduct use in ruminant nutrition while offering practical solutions for producers seeking to optimize regional feed resources and maintain animal health and productivity.