Osso trabecular de Gallus gallus

Abstract

The morphological distinctions and particularities of the bones of production animals are very evident, especially when comparing classes, such as those observed when studying birds and mammals. Bird bones, although thin and often hollow (pneumatic) to reduce weight for flight, are structurally more rigid and dense due to a greater deposition of mineral salts, mainly calcium phosphate. This higher mineral density compensates for the reduction in total bone mass and provides the necessary rigidity to withstand the stresses of flight. As a consequence, they become more rigid, but also more susceptible to fractures. To compensate for this fragility, birds have developed important physiological adaptations, including the presence of internal structures called trabecular bones or medullary bones. The present academic work aimed to highlight the anatomical differences between the bones of birds and those of mammals, focusing mainly on trabecular bones and their functions. This material was developed by academics from the extension project “Knowing, respecting and producing birds: didactic and alternative models in the teaching and learning process”, linked to the Domestic Animal Anatomy (BA065) course of the Animal Science program at the Federal University of Paraná (UFPR). Trabecular bones function as an important support structure, distributing forces and stresses more efficiently, which increases the mechanical resistance of the skeleton. In laying hens, they also act as a mineral reserve, especially calcium, which can be mobilized into the bloodstream when necessary and directed to the uterus, where it directly participates in the formation of the eggshell. This process is regulated by hormonal action, which stimulates the release and deposition of calcium according to physiological demand, making its knowledge important for feed management in animal production.