Modelling and estimation of genotype by environment interactions for production traits in French dairy cattle

Abstract

BackgroundGenotype by environment interactions are currently ignored in national genetic evaluations of dairy cattle. However, this is often questioned, especially when environment or herd management is wide-ranging. The aim of this study was to assess genotype by environment interactions for production traits (milk, protein, fat yields and fat and protein contents) in French dairy cattle using an original approach to characterize the environments.MethodsGenetic parameters of production traits were estimated for three breeds (Holstein, Normande and Montbéliarde) using multiple-trait and reaction norm models. Variables derived from Herd Test Day profiles obtained after a test day model evaluation were used to define herd environment.ResultsMultiple-trait and reaction norm models gave similar results. Genetic correlations were very close to unity for all traits, except between some extreme environments. However, a relatively wide range of heritabilities by trait and breed was found across environments. This was more the case for milk, protein and fat yields than for protein and fat contents.ConclusionsNo real reranking of animals was observed across environments. However, a significant scale effect exists: the more intensive the herd management for milk yield, the larger the heritability.

Genetic Control of Environmental Variation of Two Quantitative Traits ofDrosophila melanogasterRevealed by Whole-Genome Sequencing

“…The first definition gives rise to genotype-byenvironment interaction at the level of the mean, a topic that has a long history due to its relevance in livestock and plant breeding as well as in medical genetics. Recent articles on specific areas are Huquet et al (2012) in livestock, El-Soda et al (2014) in plants, andHutter et al (2013) in humans.The second definition implies that environmental variance is under genetic control and is the subject of the present work. Genetic control of environmental variation has implications in evolutionary biology, in animal and plant improvement, and in medicine.…”

“…The first definition gives rise to genotype-byenvironment interaction at the level of the mean, a topic that has a long history due to its relevance in livestock and plant breeding as well as in medical genetics. Recent articles on specific areas are Huquet et al (2012) in livestock, El-Soda et al (2014) in plants, and Hutter et al (2013) in humans.…”

Characterisation of terminal sire sheep farm systems, based on a range of environmental factors: a case study in the context of genotype by environment interactions using Charollais lambs

“…The studies carried out by Weigel and Rekaya (2000) and Espasandin et al (2013) are two examples where clusters of farm environments were identified across different countries, thus allowing genetic correlations to be estimated between cluster groups rather than between countries. Similar methods have also been used within countries (Neser et al, 2008;Huquet et al, 2012b). The variables used to cluster the farms, in the cattle studies mentioned above, often included information such as climatic conditions, performance indicators (such as milk yield or weight at weaning) and herd size.…”

“…For example, it may be that if the Texel data were used, the reliability of estimates associated with Cluster 3 would be improved due to the increased number of flocks allocated to this cluster. An alternative option available to breeders would be the potential use of reaction norm models, which rely less on the connectedness between individual farms because the environments are measured on a continuous scale (Huquet et al, 2012b). Further investigation, using this method, would also be beneficial.…”

Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes: I-selection goals and criteria

“…The literature mostly indicates that G × E interactions in dairy cattle are very weak for milk traits. This has been evidenced on farms subject to markedly differing environmental conditions within a country (Haile-Mariam et al, 2008), such as intensive v. grazing systems (Boettcher et al, 2003;Kearney et al, 2004), or different production levels (Huquet et al, 2012). For international breeds such as the Holstein (Mark, 2004) this difference has also been demonstrated between countries, with some of the weakest correlations (0.72 to 0.76) being seen between New Zealand and countries from Europe or North America.…”