Forage Carbohydrate Profiles and Endocrine Morphometric Interactions in Traditionally Managed Horses from Romania

Horses maintained under traditional management systems and dependent on natural forages are often exposed to seasonal and compositional variations that can affect metabolic homeostasis. This study examined associations between forage nutrient composition and metabolic-morphometric indicators in horses from four agroecologically distinct regions of northwestern Romania. Eighty-eight horses managed under semi-extensive rural conditions underwent clinical examination, body condition scoring (BCS), cresty neck scoring (CNS), and fasting blood sampling. Forage samples (n = 34) from daily rations were analyzed for fermentable carbohydrate content, while serum insulin, leptin, and adiponectin were quantified using validated equine-specific ELISA assays. Forage composition varied substantially among regions, influencing both endocrine and morphometric outcomes. Horses consuming carbohydrate-rich forages exhibited higher insulin (0.95-219 μIU/mL) and leptin concentrations (925-28,190 pg/mL), accompanied by elevated BCS and CNS scores, whereas adiponectin levels tended to decrease with increasing carbohydrate content. These findings demonstrate that naturally occurring variation in forage quality can significantly influence metabolic regulation in horses managed under low-input, traditional systems. Integrating forage nutrient evaluation with clinical and endocrine assessments provides a practical framework for identifying animals at risk of metabolic dysfunction and guiding nutritional strategies to mitigate the incidence of laminitis and related disorders.