Persistence of Infection with Gastrointestinal Nematodes during the Fattening of Hair Lambs Supplemented with Virginiamycin

Background: Gastrointestinal nematodes (GIN) are a common problem that affects sheep health and production. There are strategies that have been used to combat these opportunistic microorganisms: chemical agents, nutraceutical plants and nutritional management to reduce the parasite load in animals. Nutrition management can increase resilience, reducing parasitism and increasing immunity to parasites in sheep. Evaluate the persistence of the infection with gastrointestinal nematodes during the fattening of stabled sheep and supplemented with virginiamycin. Methods: 27 lambs of three months of age were distributed in three groups of nine lambs; a control group (CG) and two groups supplemented with virginiamycin powder at 10 and 15 mg/kg per body weight in the diet during 75 days. Result: The supplementation with 10 and 15 g of virginiamycin in lambs crosses Pelibuey x Dorper decreases the FEC count of T. colubriformis and Strongyles spp. on days 3 and 5 of the experimental period.