Humoral Immune Response in Pelibuey Ewes to Haemonchus contortus Antigen During the Peripartum Period

The anthelmintic resistance in endo-parasites forces the search for different alternatives to control gastrointestinal nematodes. One choice is promoting the natural resistance of the host to self-regulate gastrointestinal nematodes infections, as a sustainable method. The aim of this study was to analyze the performance of immunoglobulins A, G, and M in Pelibuey ewes infected with gastrointestinal nematodes during the peripartum period. Hematological and fecal egg count of H. contortus were recorded. In addition, blood serum obtained from 31 three-year-old Pelibuey ewes in the peripartum stage was used to detect antibodies against crude antigen of nematodes by indirect enzyme linked immunosorbent assay. Data from Pelibuey ewes were grouped by physiological stage (pregnancy and lactation) and divided into early (weeks 1–6), mid (weeks 7–14), and late (weeks 15–22) pregnancy. Lactation was also divided into early (weeks 1–4 post-partum), mid (weeks 5–9), and late (weeks 10–13) lactation. Data were analyzed as repeated measures over time. Fecal egg counts of gastrointestinal nematodes showed differences between pregnancy and lactation (p < .03), with lower fecal egg count during pregnancy (279 ± 86 eggs per gram of feces) than during lactation (489 ± 46 eggs per gram of feces). The susceptible ewes showed values greater than 1054 ± 1099 eggs per gram of feces, while the resistant ones showed fecal egg count on average of 81 ± 152 eggs per gram of feces. The relative expression of IgG and IgM was significantly higher during pregnancy (51.39% and 46.15%, respectively) compared to lactation (38.25% and 38.49%, respectively). The IgA response in resistant ewes had a significantly higher expression (32.7%) compared to the intermediate (19.6%) and susceptible (20.5%) groups. IgA stands out for its direct relationship with parasite inhibition, evidenced by negative correlations with eggs per gram of feces. Immunoglobulins (A, G, and M) have a relevant role in the humoral immune response during the peripartum period.

Cite this article as: Pulido-López, M. G., Hernández-Mendo, O. , González-Garduño, R. , Torres-Hernández, G. , & Gallegos-Sánchez, J. (2026). Humoral immune response in pelibuey ewes to Haemonchus contortus antigen during the peripartum period. Acta Veterinaria Eurasia, 52, 0230, doi:10.5152/actavet.2026.25230.