Investigating the effect of passive immunization, mediated by colostrum from ewes vaccinated with Haemonchuscontortus ES24 antigen on haemonchosis resistance in suckling lambs.

• Grant number: 25/10259-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2025
• End date: July 31, 2027
• Field of knowledge: Biological Sciences - Immunology - Applied Immunology
• Principal Investigator: Cintia Hiromi Okino
• Grantee: Mateus Oliveira Mena
• Host Institution: Embrapa Pecuária Sudeste. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). São Carlos , SP, Brazil
• Associated research grant: 24/09500-0 - Immunotherapy in lambs using specific antibodies against the recombinant 24kDa excretory-secretory protein of Haemonchus contortus., AP.R

Abstract

Twenty White Dorper ewes will be bred with two rams of the same breed. Pregnant ewes will be identified. In thepre-lambing period, half of the pregnant ewes will receive an intramuscular immunization with a 24kDa excretory-secretory recombinant protein of Haemonchus contortus combined with an oil adjuvant; the other half will receiveonly the adjuvant. Plasma samples will be collected from all ewes at 0, 14, and 28 days post-immunization. Afterlambing, milk/colostrum and plasma samples will be collected from the ewes, and plasma and nasal mucosalsecretion samples will be collected from the lambs at 0, 14, 28, and 62 days, as well as at weaning (approximately90 days of age). Plasma, milk/colostrum, and nasal mucosa samples will be analyzed for specific anti-ES24 andanti-L3 H. contortus antibodies of the IgG, IgM, and IgA isotypes using an indirect ELISA technique. Packed cellvolume (PCV) and lamb weight gain will be monitored at the same intervals. Fecal egg counts (FEC), expressed aseggs per gram of feces (EPG), will be performed at 62 days and at weaning. All results will be subjected tostatistical analysis using RStudio software. (AU)