Genetic parameters for worm resistance in Santa Inês sheep using the Bayesian animal model

Objective: The objective of this study was to estimate the genetic parameters for worm resistance (WR) and associated characteristics, using linear-threshold animal model via Bayesian inference in single- multiple-trait analyses.Methods: Data were collected from a herd Santa Inês breed sheep. All information with animals submitted natural contamination conditions. data (number eggs per gram feces [FEC], Famacha score [FS], body condition [BCS], hematocrit [HCT]) on same day. weighed individually day after collection (after 12-h fasting). WR trait defined by multivariate cluster analysis, FEC, HCT, BCS, FS material naturally infected sheep breed. variance components WR, traits estimated under linear threshold model.Results: A low magnitude obtained repeatability worm-related traits. mean values heritability low-to-high (0.05 0.88) magnitude. FS, weight showed higher (although magnitude) due increased about characters significant correlation, estimates ranged (0.44; single-trait model) high (0.88; model).Conclusion: Therefore, we suggest that be included as criterion ovine selection endoparasite it will provide greater gains when compared any single trait. In addition, its measurement is easy inexpensive, exhibiting correlation worms.