Electrophoretic Pattern of Serum Proteins and Concentrations of Serum Protein Fractions in Lambs Infected With Haemonchus contortus

The aim of this study was to evaluate the blood serum protein profile separated by electrophoresis in 10 lambs experimentally infected with Haemonchus contortus and to describe the changes in the distribution of serum protein fractions over a 107‐day postinfection period. These lambs were a part of a previous experiment that examined the effects of alternative treatment on the H. contortus infection. Blood samples were collected from 10 lambs infected with H. contortus on Days 0 (before infection), 14, 28, 42, 56, 70, 84, 98, and 107 postinfection. Total serum protein concentrations were analyzed using the biuret method, and the major protein fractions were separated with agarose gel electrophoresis. Only one lamb showed clinically observable signs of haemonchosis; these results were excluded from the statistical analysis. Changes in the analyzed parameters in animals without clinical signs ( n  = 9) were highly significant, except for the relative values of β1‐globulins. The most notable changes after infection were observed between Days 14 and 42, where the absolute concentrations of total proteins, albumin, α ₂ ‐, β ₁ ‐, and γ ₁ ‐globulins decreased significantly ( p < 0.05 to p < 0.001). Conversely, the relative concentrations of α ₁ ‐and α ₂ ‐globulins increased ( p < 0.01 and p < 0.001, respectively), and γ ₁ ‐globulin decreased ( p < 0.01). From Day 56 onward, several parameters showed a steady trend toward baseline values before infection. The changes observed in the lamb with clinical signs were more severe, characterized by extremely low total protein and albumin levels and markedly higher relative values of α ‐ and γ ‐globulin fractions on Days 98 and 107 postinfection. These results suggest that alterations in the protein profile and serum protein fraction distribution occur even in animals infected with H. contortus without clinical symptoms, which should be considered when addressing this health issue.