Fecha/hora: 22/05/2024 23:03:23

Biblioteca(s): 	INIA Las Brujas.	
Tipo de la producción científica: 	Artículos en Revistas Indexadas Internacionales	
Circulación/Nivel: 	B - 1	
Fecha corriente: 	26/09/2014	
Fecha de la última actualización: 	15/10/2019	
Autoria: 	GOLDBERG, V.; CIAPPESONI, C.; AGUILAR, I.	
Afiliación: 	VIRGINIA GOLDBERG BIANCHI, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay; CARLOS GABRIEL CIAPPESONI SCARONE, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay; IGNACIO AGUILAR GARCIA, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay.	
Título: 	Genetic parameters for nematode resistance in periparturient ewes and post-weaning lambs in Uruguayan Merino sheep.	
Año de publicación: 	2012	
Fuente/Imprenta: 	Livestock Science, 2012, v.147, no.1-3, p.181-187.	
DOI: 	10.1016/j.livsci.2012.05.003	
Idioma: 	Inglés	
Notas: 	Article history: Received 14 December 2011 / Received in revised form 2 May 2012 / Accepted 3 May 2012.	
Contenido: 	ABSTRACT.

Gastrointestinal (GI) parasites are one of the main sanitary and economic constraints for sheep production worldwide. In Uruguay, resistance to GI parasites has been included in genetic evaluations of Merino and Corriedale breeds since 1994, using Faecal worm Egg Count measured in post-weaning lambs (lambFEC) as a selection criterion. Although adult categories are more resistant to GI parasites, a temporary loss of acquired immunity is present in the periparturient period (=periparturient rise). The purpose of the present study is to estimate the genetic parameters of resistance to GI parasites in periparturient ewes and post-weaning Merino lambs. A total 2110 faecal samples of 748 periparturient ewes (eweFEC), the progeny of 107 sires, were collected in 2009 and 2010. 9458 lambFEC records from 7506 lambs born between 2001 and 2009 were analysed as well. (Co)variance components and systematic effects were estimated using a multi-trait animal model, with a Bayesian analysis using the Gibbs sampler algorithm. Direct and correlated responses (DR and CR) of eweFEC to selection using eweFEC and lambFEC respectively, were also estimated. Posterior medians (posterior standard deviation) for heritability (h2) and repeatability were 0.25 (0.03) and 0.34 (0.02) for lambFEC, and 0.08 (0.03) and 0.18 (0.03) for eweFEC, respectively. Posterior median for genetic correlation between both traits was 0.81 (0.11). CR obtained by selecting for lambFEC was two times more efficient than DR from selection by eweFEC. In conclusion, eweFEC has a lower h2 than lambFEC while their genetic correlation is moderate to high. Therefore, indirect selection by using lambFEC will be more effective than direct selection on eweFEC, and will produce ewes that eliminate less worm eggs, resulting in less pasture contamination. 
© 2012 Elsevier B.V..	
Palabras-Clave: 	FEC.	
Thesagro: 	MEJORAMIENTO GENETICO ANIMAL.	
Categoría del tema: 	L10 Genética y mejoramiento animal	
Registro original: 	INIA Las Brujas (LB)	
Ejemplares: 	LB - (100110-1) - PXI - AP - DD - PP/LIVESTOCK SCIENCE/2012 -  -  - DIS