Combined analysis of data from two granddaughter designs: A simple strategy for QTL confirmation and increasing experimental power in dairy cattle.
A joint analysis of five paternal half-sib Holstein families that were part of two different granddaughter designs (ADR- or Inra-design) was carried out for five milk production traits and somatic cell score in order to conduct a QTL confirmation study and to increase the experimental power. Data were exchanged in a coded and standardised form. The combined data set (JOINT-design) consisted of on average 231 sires per grandsire. Genetic maps were calculated for 133 markers distributed over nine chromosomes. QTL analyses were performed separately for each design and each trait. The results revealed QTL for milk production on chromosome 14, for milk yield on chromosome 5, and for fat content on chromosome 19 in both the ADR- and the Inra-design (confirmed within this study). Some QTL could only be mapped in either the ADR- or in the Inra-design (not confirmed within this study). Additional QTL previously undetected in the single designs were mapped in the JOINT-design for fat yield (chromosome 19 and 26), protein yield (chromosome 26), protein content (chromosome 5), and somatic cell score (chromosome 2 and 19) with genomewide significance. This study demonstrated the potential benefits of a combined analysis of data from different granddaughter designs.
Bennewitz
Jörn
J
Institut für Tierzucht und Tierhaltung, Christian-Albrechts-Universität, 24098 Kiel, Germany. jbennewitz@tierzucht.uni-kiel.de
Reinsch
Norbert
N
Grohs
Cécile
C
Levéziel
Hubert
H
Malafosse
Alain
A
Thomsen
Hauke
H
Xu
Ningying
N
Looft
Christian
C
Kühn
Christa
C
Brockmann
Gudrun A
GA
Schwerin
Manfred
M
Weimann
Christina
C
Hiendleder
Stefan
S
Erhardt
Georg
G
Medjugorac
Ivica
I
Russ
Ingolf
I
Förster
Martin
M
Brenig
Bertram
B
Reinhardt
Fritz
F
Reents
Reinhard
R
Averdunk
Gottfried
G
Blümel
Jürgen
J
Boichard
Didier
D
Kalm
Ernst
E
D000818:Animals; D002417:Cattle / Q000235:genetics*; D002874:Chromosome Mapping; D003612:Dairying; D003627:Data Interpretation, Statistical; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D008957:Models, Genetic; D010375:Pedigree; D040641:Quantitative Trait Loci / Q000235:genetics*
D005819:Genetic Markers