Thus, producers can make early management decisions based on the predicted individual production. Lactation curves provide a description of milk yield performance, which make it possible to predict total milk yield from a single or several test days early in lactation. NCSS can be used to estimate EBV for lactation persistency and total milk yield, which in turn can be used in whole-genome association studies.įor dairy producers, the accurate description of lactation curves is a valuable tool for selection and management. Several SNP were found to be associated with both traits and these were used to identify candidate genes for further investigation. Persistency EBV were correlated with peak yield but not with total milk yield. ResultsĮstimated sire breeding values (EBV) for persistency and milk yield were calculated using NCSS. The sire solutions for persistency and total milk yield were derived using NCSS and a whole-genome approach based on a hierarchical model was developed for a large association study using single nucleotide polymorphisms (SNP). NCSS were used to model the sire effect on the lactation curves of cows. It has been shown that Natural Cubic Smoothing Splines (NCSS) can model the features of lactation curves with greater flexibility than the traditional parametric methods.
Fixed effects asreml stratum drivers#
Understanding the genetic drivers for the phenotypic variation of both these traits could provide a means for improving these traits in commercial production. From a breeding and production viewpoint, milk yield persistency and total milk yield are important traits.
Fixed effects asreml stratum plus#
Collectivement, la survie durant le stade de vie en eau douce pourrait être plus grande pour les individus d’ascendance domestiquée que pour les individus d’ascendance génétique sauvage en présence de prédateurs dont la commissure des mâchoires est limitée, qui préfèrent de plus petits individus en revanche, le succès de reproduction des mâles pourrait être plus faible pour les individus domestiqués, leur potentiel de reproduction durant l’étape en eau douce étant réduit.For dairy producers, a reliable description of lactation curves is a valuable tool for management and selection. La probabilité de maturation des tacons mâles ajustée selon la taille était de 34 % dans la lignée sauvage, mais significativement réduite à 10 % et 7 %, respectivement, après trois et cinq générations de domestication. La croissance en présence d’une menace de prédation n’était réduite que pour les individus sauvages, ce qui donne à penser qu’il y a cosélection par la domestication d’une résistance au stress associé aux prédateurs. Une taille initialement plus grande et la capacité de dépasser la taille de proie plus rapidement se sont traduites par une mortalité par prédation selon la taille plus faible pour les individus domestiqués. La sélection associée à une croissance rapide sur trois et cinq générations dans deux lignées s’est traduite par des tailles de deux à trois fois plus grandes des tacons de moins d’un an par rapport à celles de leurs ancêtres sauvages. Nous avons étudié les modifications de caractères associés à l’aptitude provoquées par la domestication chez le saumon atlantique ( Salmo salar) dans des conditions de laboratoire enrichies naturellement avec et sans menace de prédation. La domestication peut modifier des caractères associés à l’aptitude. Together, freshwater-stage-specific survival for individuals with a domesticated background relative to individuals with a wild genetic background might be higher in the presence of gape-limited predators preferring small individuals, but male reproductive success might be lower for domesticated individuals as their reproduction potential during the freshwater phase is reduced. Size-adjusted male parr maturation probability was 34% in the wild strain, but significantly reduced to 10% and 7% after three and five generations of domestication, respectively. Growth under threat of predation was only reduced for wild individuals, suggesting that domestication co-selects for predator-related stress resistance.
An initially larger size and ability to outgrow prey size more rapidly resulted in lower size-selective predation mortality for domesticated individuals. Selection in two strains for rapid growth for three and five generations resulted in two and three times larger sizes of under-yearling parr relative to their wild ancestor. We investigated domestication-induced changes in fitness-related traits in Atlantic salmon ( Salmo salar) under naturally enriched laboratory conditions with and without threat of predation. Domestication can change fitness-related traits.
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