Genotype by environment interaction and heteroscedasticity influence the expression of parasite resistance in Katahdin sheep.
J Anim Sci
; 1012023 Jan 03.
Article
en En
| MEDLINE
| ID: mdl-37407224
Sheep producers increasingly rely on breeds that express resistance to gastrointestinal parasites because anthelminthic drugs are often ineffective. An example is Katahdin sheep, which are raised in various climates and management systems in the United States. These factors can be combined into eco-management clusters to describe production environments more holistically. Our objective was to determine if a genotype by eco-management cluster (environment) interaction (Gâ
×â
E) affected performance levels, particularly for traits indicative of parasite resistance. Body weights (BW), fecal egg counts (FEC), and FAMACHA scores (FAM) were collected at around 90 d in 3,527 Katahdin lambs delineated into nine eco-management clusters. Heritabilities of BW, FEC, and FAM were 0.36, 0.31, and 0.26, respectively. Genetic correlations of BW with FEC and FAM were low to moderate and favorable (negative). When estimated within eco-management cluster, heritabilities were 0.30 to 0.37 for BW, 0.18 to 0.50 for FEC, and 0.07 to 0.40 for FAM. For FEC and FAM, these differences corresponded with heterogenous variances (heteroscedasticity) across environments. Furthermore, Gâ
×â
E explained 13% (FAM) to 20% (BW) of the variation in a trait. In genetic evaluation of parasite resistance, Gâ
×â
E and heteroscedasticity should be incorporated to improve the efficacy of the breeding program.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Parásitos
/
Enfermedades de las Ovejas
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Anim Sci
Año:
2023
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos