title: Quantitative trait loci analysis for leg weakness-related traits in a Duroc × Pietrain crossbred population.
abstract: BACKGROUND
  Leg weakness issues are a great concern for the pig breeding industry, especially with regard to animal welfare. Traits associated with leg weakness are partly influenced by the genetic background of the animals but the genetic basis of these traits is not yet fully understood. The aim of this study was to identify quantitative trait loci (QTL) affecting leg weakness in pigs.
  
  
  METHODS
  Three hundred and ten F₂ pigs from a Duroc × Pietrain resource population were genotyped using 82 genetic markers. Front and rear legs and feet scores were based on the standard scoring system. Osteochondrosis lesions were examined histologically at the head and the condylus medialis of the left femur and humerus. Bone mineral density, bone mineral content and bone mineral area were measured in the whole ulna and radius bones using dual energy X-ray absorptiometry. A line-cross model was applied to determine QTL regions associated with leg weakness using the QTL Express software.
  
  
  RESULTS
  Eleven QTL affecting leg weakness were identified on eight autosomes. All QTL reached the 5% chromosome-wide significance level. Three QTL were associated with osteochondrosis on the humerus end, two with the fore feet score and two with the rear leg score. QTL on SSC2 and SSC3 influencing bone mineral content and bone mineral density, respectively, reached the 5% genome-wide significance level.
  
  
  CONCLUSIONS
  Our results confirm previous studies and provide information on new QTL associated with leg weakness in pigs. These results contribute towards a better understanding of the genetic background of leg weakness in pigs.
authors.affiliation: Institute of Animal Science, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Watchara
authors.initials: W
authors.lastname: Laenoi
authors.forename: Muhammad Jasim
authors.initials: MJ
authors.lastname: Uddin
authors.forename: Mehmet Ulas
authors.initials: MU
authors.lastname: Cinar
authors.forename: Christine
authors.initials: C
authors.lastname: Grosse-Brinkhaus
authors.forename: Dawit
authors.initials: D
authors.lastname: Tesfaye
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Jonas
authors.forename: Armin M
authors.initials: AM
authors.lastname: Scholz
authors.forename: Ernst
authors.initials: E
authors.lastname: Tholen
authors.forename: Christian
authors.initials: C
authors.lastname: Looft
authors.forename: Klaus
authors.initials: K
authors.lastname: Wimmers
authors.forename: Chirawath
authors.initials: C
authors.lastname: Phatsara
authors.forename: Heinz
authors.initials: H
authors.lastname: Juengst
authors.forename: Helga
authors.initials: H
authors.lastname: Sauerwein
authors.forename: Manfred
authors.initials: M
authors.lastname: Mielenz
authors.forename: Karl
authors.initials: K
authors.lastname: Schellander
mesh_terms: D000818:Animals; D015519:Bone Density / Q000235:genetics; D001947:Breeding; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D005528:Foot / Q000502:physiology*; D005819:Genetic Markers; D018908:Muscle Weakness / Q000235:genetics*; D055034:Osteochondrosis / Q000235:genetics / Q000473:pathology; D040641:Quantitative Trait Loci / Q000235:genetics*; D034421:Sus scrofa / Q000235:genetics*
chemical_list: D005819:Genetic Markers