Anatomical and topographic features of the kidneys of hens of the Hysex White cross

Poultry farming in Russia occupies a promising and strategic position in the agro-industrial complex, acting as a key source of providing the population with high-quality protein products such as meat and eggs. The urinary system in domestic birds has unique anatomical features, namely the absence of a bladder, direct excretion of urine through the cloaca. The kidneys of birds perform not only the function of filtering blood and removing metabolites, but also participate in calcium metabolism, which is critically important for the formation of eggshells. Fresh carcasses of ten individuals of the Hysex White cross were used as the research material. A study of the anatomical and topographic features of the kidneys of hens of the Hysex White cross revealed a number of differences between males and females. In males, the kidneys are larger, which is due to their greater body weight and increased intensity of metabolic processes. A more active water-salt exchange associated with behavioral factors requires increased filtration capacity. Anatomical asymmetry was found in both sexes: the left kidney is larger than the right one. This is due to the topography: the right kidney borders the liver, which limits its growth in the cranial direction. Analysis of the blood supply showed that the diameter of the renal vessels in males is larger than in females. This feature is associated with the influence of testosterone, which stimulates the development of vascular smooth muscle and enhances angiogenesis. In addition, the high body weight of males requires increased blood flow to supply the kidneys with oxygen and nutrients. These morphological differences reflect the evolutionary adaptation to sexual dimorphism in physiology and energy requirements typical of birds. In hens of Hysex White, such features are more pronounced due to breeding for high productivity, which can enhance the sexual specificity of the vascular system structure.