EPIDEMIOLOGICAL PROFILE OF GASTROINTESTINAL NEMATODE INFECTIONS AND EVALUATION OF ANTHELMINTIC RESISTANCE IN SHEEP AND GOATS: IMPACTS ON HERD HEALTH AND PRODUCTIVITY

• Grant number: 24/15324-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: José Gabriel Gonçalves Lins
• Grantee: Camila Rios da Silva
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Sheep and Goat Farming in Brazil face challenges due to infections by gastrointestinal nematodes (GINs), causing significant economic losses. This project aims to assess the profile of these helminths and the resistance to anti-helminthic drugs in sheep and goat herds at the teaching, research, and extension farms of UNESP. Resistance to anti-helminthic drugs is a growing problem, complicating the effective treatment of parasitic infections and negatively impacting animal production. The study also aims to propose parasitic control strategies based on epidemiological data and the efficacy testing of anti-helminthic drugs. The study will be conducted in sheep and goat production units at the UNESP teaching farms. Field clinical trials will be carried out to evaluate the anti-helminthic efficacy of different molecules available on the market. The animals will be divided into experimental groups following criteria established by the World Association for the Advancement of Veterinary Parasitology. To assess efficacy, fecal samples will be collected at two distinct times (Day 0 and Day 14) for laboratory analysis, including egg count per gram of feces (EPG) and coproculture to identify infective third-stage larvae (L3) of GINs. The results of efficacy tests will be presented using the Fecal Egg Count Reduction Test (FECRT). A drug will be considered effective when it shows a reduction in egg count in feces (RECF) ¿95%, with a confidence interval ¿90%. Resistance of GINs to drugs will be attributed when the RECF is <95% with a confidence interval <90%. The research seeks to contribute to mitigating the problems faced by sheep and goat farming due to GIN infections in UNESP herds, providing data for the establishment of management and treatment strategies. Anti-helminthic resistance is a significant challenge that requires integrated and strategic approaches to ensure the health and welfare of the herds, as well as the sustainability of animal production. Implementing prophylactic and therapeutic measures based on scientific evidence will help reduce economic losses and promote more sustainable animal production, also enhancing the health and welfare of the herds.