Impact of hemoparasite load on hematological, biochemical, and immunological parameters in ISA Brown laying hens in southern Togo.

Abstract

BACKGROUND: One of the major causes of economic losses in layer hen farming in Togo is the infestation of these birds by hemoparasites. OBJECTIVES: This study aimed to determine the prevalence of hemoparasites in laying hens and assess their impact on hematological, biochemical, and immunological parameters. MATERIALS AND METHODS: The study was conducted in southern Togo, specifically in the localities of Vo, Ave, and Golf. Fifty heavily parasitized Isa Brown laying hens, aged between 26 and 46 weeks, were selected. Blood samples were collected directly from the heart. Blood smears were made from drops of blood with unmeasured volume, air-dried, fixed with methanol, and stained using the rapid RAL 555 technique. The slides were examined under a light microscope at 100× magnification, followed by detailed observation under oil immersion at 1000× magnification. RESULTS: Analysis revealed hematological, biochemical, and immunological alterations associated with hemoparasitic infections. Babesia spp. and Leucocytozoon spp. were identified using Soulsby's method (1982). Hematological analyses showed decreased red blood cell counts (RBC), which is 1.60 ± 0.71; 1.49 ± 0.49; 2.82 ± 0.28 respectively in bird infested by Babesia spp. (Ba), Leucocytozoon spp. (Leu) and Uninfected (Ni). In other hand, Reduced hematocrit levels (Leu = 31.03 ± 6.34; 23.25 ± 3.76) in infected hens was noted. Differential leukocyte counts revealed monocytosis, lymphocytosis, and eosinophilia. Biochemical analysis of collected serum samples indicated significant differences (p = 0.03; p = 0.008) in serum protein levels and Aspartate Aminotransférase (AST) between infected and uninfected birds. Immunological assays also showed significant differences (p ≤ 0.001) in beta- and gamma-globulin concentrations between the two groups. Furthermore, significant variation (p = 0.027) in the density of Babesia spp. (1.31) and Leucocytozoon spp. (0.78) was observed among infected hens. CONCLUSION: These findings offer helpful physiological markers for early detection and emphasize the significance of hemoparasitic infections in the decline of laying hen health. Integrating these findings into management practices could optimize health-related decision-making and reduce economic losses in poultry farming.