Abstract
<jats:p>Vitamin and mineral deficiencies, as well as imbalances in their ratios, have a critical impact on bone and joint health in birds, leading to a range of osteo-articular disorders that affect skeletal development, productivity, and welfare. A primary example is the calcium-phosphorus ratio. In broilers, deficiencies halt bone mineralization, causing rickets, while in adults, the same deficit results in osteoporosis with reduced bone density, skeletal alterations, and increased fracture risk. The condition is exacerbated when calcium deficiency is combined with excess phosphorus, promoting tibial dyschondroplasia, characterized by abnormal cartilage development at the proximal tibial growth plate and spontaneous fractures. Electrolyte imbalances, such as excessive sodium with low potassium, further increase susceptibility. Trace elements play a similarly vital role. Manganese and zinc deficiencies lead to perosis, presenting as shortened bones, tibiometatarsal joint hypertrophy, and Achilles tendon malposition. Copper deficiency causes lameness, bone fragility, and epiphyseal thickening, emphasizing its importance in skeletal integrity. Vitamin D3 is central to calcium and phosphorus absorption; its deficiency promotes rickets and osteoporosis even with adequate dietary minerals. B-complex vitamin deficiencies correlate with neurological and musculoskeletal signs, including polyneuritis, myelin degeneration, tibiotarsal instability, varus/valgus deformities, and perosis. Vitamin A deficiency, typically after seven weeks, causes anorexia, weakness, and uncoordinated gait without directly affecting locomotion. Vitamin E deficiency leads to ataxic movements, though these signs indicate encephalomalacia rather than osteo-articular disease. Thus, skeletal health in birds depends on a precise balance of minerals, trace elements, and vitamins. Any deficiency or improper ratio can trigger pathological mechanisms compromising skeletal development and performance. Maintaining optimal nutritional balance, rather than focusing solely on individual supplements, is essential to ensure bone integrity and overall bird welfare.</jats:p>