marker-assisted selection in wheat - ictsd

Chapter 12 – Marker-assisted selection in dairy cattle 211Table 1Summary of dairy cattle genome scansExperimentaldesignBreed Country Traits analysed ReferencesGranddaughter Ayrshire Finland Milk production 1 Vilkki et al., 1997; de Koning et al.,2001; Viitala et al., 2003SCS 2 , mastitis, other treatments Schulman et al., 2004Jersey New Zealand Conformation Spelman, Garrick and vanArendonk, 1999Holstein Canadian Milk production Plante et al., 2001France Milk production Boichard et al., 2003Germany Milk production Thomsen et al., 2001Functional Kuhn et al., 2003Conformation, temperament, Hiendleder et al., 2003milking speedNetherlands conformation, SCS, fertility, Schrooten et al., 2000calving, milking speed,gestation, birth weight,temperamentNew Zealand Conformation Spelman, Garrick and vanArendonk, 1999USA Milk production Ashwell et al., 1998b; Ashwell andTassell 1999; Ashwell et al., 1997,2004; Ashwell, Van Tassell andSonstegard, 2001;Georges et al.,1995; Heyen et al., 1999; Zhang etal., 1998SCS Ashwell et al., 1996, 1997, 1998b;Ashwell and Van Tassell, 1999;Heyen et al., 1999Herdlife Heyen et al., 1999Conformation Ashwell et al., 1998a, 1998b;Ashwell and Van Tassell, 1999Fertility Ashwell et al., 2004Montbeliarde France Milk production Boichard et al., 2003Normande France Milk production Boichard et al., 2003Norwegian Norway Milk production Olsen et al., 2002SCS, mastitis Klungland et al., 2001Swedish Sweden SCS, mastitis, other diseases Holmberg and Andersson-Eklund,2004Daughter Holstein Israel Milk production, SCS, fertility, Ron et al., 2004herdlife% protein Mosig et al., 20011Milk, fat, and protein production, and fat and protein concentration.2Somatic cell concentrationenvironmental factors. Cows are scatteredover many different herds with differentmanagement levels, and distribution of siresacross herds is not random or orthogonal.Furthermore, cows generally producemultiple lactations that are correlated. Inorder to account for the limited heritability,and co-variances among relatives, geneticeffects are generally assumed to berandom, while most environmental effectsare assumed to be fixed. Thus, geneticevaluation is performed by the mixedmodel using best linear unbiased prediction(BLUP) methodology (Henderson, 1984).Beginning in the late 1980s, the modelof choice for genetic evaluation for milkproduction traits was the individual animalmodel, in which a genetic effect is computed