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Sustainable dairy farming - A case study of Holsteins in a developed and an emerging country
Hammami, Hedi; Rekik, Boulbaba; Bormann, Jeanne et al.
2009IDF World Dairy Summit 2009
 

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Abstract :
[en] Sustainability of breeding programs under the flow of exchange among various environments are conditioned by the ability of genotypes to adjust sufficiently their phenotypes in response to changes in their new bio-physical conditions, and also by the capabilities of farmers to balance between environmental, ethical, social. and economic aspects. The objective of this paper was to quantify the effectiveness of genetic responses from indirect selection in high- and low- to medium- input systems using Luxembourg and Tunisian Hoisteins. The magnitude of genotype-by-environment interaction (GxE) for production traits was firstly investigated based on the country border delimitation as environmental character state. Secondly, three herd management levels reflecting feeding and management intensity were identified in each country and GxE was investigated within and across country environments. Significant GxE was detected for milk yield and persistency with large differences in genetic and permanent environmental variances between the 2 countries. Genetic correlations for 305-d milk yield and persistency between Luxembourg and Tunisia were 0.60 and 0.36. Low rank correlations obtained between estimated breeding values of common sires translated a significant re-ranking between the 2 countries. Within-country environments analysis show that the magnitude of GxE varied from only scaling effects resulting from heterogeneous variances in high-input systems to considerable re-ranking of common sires under limited feeding resources, low management care, and stressful conditions in low-input systems. Overall, this study shows that substantial differences exist between Hoisteins in terms of their sensitivity to production environ ment suspecting the sustainability of the dairying system. In high-input systems, GxE effects are expected to be easily managed but harmful effects of intensive dairy systems should be considered. Selection of breeds under less intensive production systems respecting the ruminant's specificities should be encouraged. In law-input systems, selection for adaptive traits under their specifie conditions and improvement of management conditions and husbandry practices are needed.
Disciplines :
Genetics & genetic processes
Animal production & animal husbandry
Author, co-author :
Hammami, Hedi ;  Université de Liège - ULiège > Gembloux Agro-Bio Tech > Gembloux Agro-Bio Tech
Rekik, Boulbaba;  Ecole Supérieure d'Agriculture de Mateur > Productions animales
Bormann, Jeanne;  Administration des Services Techniques de l'Agriculture, Luxembourg
Stoll, Jean;  Convis Herbuch Service Elevage et Génétique > R&D
Gengler, Nicolas  ;  Université de Liège - ULiège > Gembloux Agro-Bio Tech > Gembloux Agro-Bio Tech
Language :
English
Title :
Sustainable dairy farming - A case study of Holsteins in a developed and an emerging country
Publication date :
23 September 2009
Event name :
IDF World Dairy Summit 2009
Event organizer :
GERMAN NATIONAL COMMITTEE
Event place :
Berlin, Germany
Event date :
20-24 septembre 2009
Audience :
International
Available on ORBi :
since 17 October 2009

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