Abstract
The study of macro-morphological changes is important for recognizing disturbances in egg formation that cause pathologies, especially co-infection. The current study aimed to evaluate the level of egg productivity and macro-morphological parameters of eggs in domestic chickens of the Rhode Island breed with co-infection of Histomonas, Trichomonas, and Eimeria. Clinical and parasitological, coproscopic, morphometric research, and statistical analysis methods were used for this research. Pathogens of Histomonas and Trichomonas were detected by microscopy of smears of fresh feces, and Eimeria oocysts were identified by flotation according to the Fullenborn method. During 30 days of research, there was a significant decrease in egg production (52%), a decrease in egg weight by 16.8%, and a decrease in the shell thickness by 30.43% during spontaneous Eimeria-Histomonosis-Trichomonosis co-infection in laying hens. The eggshell indicated noticeable macro-morphological changes, including deformations and defects resulting from insufficient calcification. These changes manifest as combined damage to the shell, characterized by small cracks, roughness, bumpy or spilled thickenings, and complete or partial depigmentation. When evaluating the internal content of eggs in 12% of their samples, there were bloody spots, relatively smaller and lighter yolks, thinning of the protein part. Thus, the specified macro-morphological changes and egg defects were the result of the negative impact of co-infection on the processes of egg formation, which indicates the systemic nature of the lesion and the morphofunctional insufficiency of the egg-forming organs.