Analysis of genetic diversity in four Canadian swine breeds using pedigree data

M G Melka, F. Schenkel
2010 Canadian Journal of Animal Science  
Melka, M. G. and Schenkel, F. 2010 . Analysis of genetic diversity in four Canadian swine breeds using pedigree data. Can. J. Anim. Sci. 90: 331Á340. Conservation of animal genetic resources entails judicious assessment of genetic diversity as a first step. The objective of this study was to analyze the trend of within-breed genetic diversity and identify major causes of loss of genetic diversity in four swine breeds based on pedigree data. Pedigree files from Duroc (DC), Hampshire (HP),
more » ... pshire (HP), Lacombe (LC) and Landrace (LR) containing 480 191, 114 871, 51 397 and 1 080 144 records, respectively, were analyzed. Pedigree completeness, quality and depth were determined. Several parameters derived from the in-depth pedigree analyses were used to measure trends and current levels of genetic diversity. Pedigree completeness indexes of the four breeds were 90.4, 52.7, 89.6 and 96.1%, respectively. The estimated percentage of genetic diversity lost within each breed over the last three decades was approximately 3, 22, 12 and 2%, respectively. The relative proportion of genetic diversity lost due to random genetic drift in DC, HP, LC and LR was 74.5, 63.6, 72.9 and 60.0%, respectively. The estimated current effective population size for DC, HP, LC and LR was 72, 14, 36 and 125, respectively. Therefore, HP and LC have been found to have lost considerable genetic diversity, demanding priority for conservation. Key words: Genetic drift, effective population size Melka, M. G. and Schenkel, F. 2010. Analyse de la diversite´ge´ne´tique de quatre races de porc canadiennes a'partir des donne´es ge´ne´alogiques. Can. J. Anim. Sci. 90: 331Á340. La pre´servation des ressources ge´ne´tiques animales suppose avant tout une e´valuation judicieuse de la diversite´ge´ne´tique. L'e´tude devait analyser les tendances de la diversite´ge´ne´tique au sein de la race et identifier les principales raisons pour lesquelles cette diversite´s'amoindrit chez quatre races de porc, d'apre's les donne´es ge´ne´alogiques. À cette fin, les auteurs ont analyse´l'ascendance des races Duroc ( DC), Hampshire (HP), Lacombe (LC) et Landrace (LR) graˆce aux dossiers contenant respectivement 480 191, 114 871, 51 397 et 1 080 144 entre´es. Ils ont de´termine´la comple´tude, la qualite´et l'e´tendue de la ge´ne´alogie. Plusieurs parame'tres de´rive´s de ces analyses approfondies ont permis de mesurer les tendances et le degre´actuel de diversite´ge´ne´tique. L'indice de comple´tude pour chacune des quatre race s'e´tablissait respectivement a'90,4, 52,7, 89,6 et 96,1%. Le pourcentage de diversite´ge´ne´tique qu'on estime avoir perdu au sein de chaque race au cours des trois dernie'res de´cennies se chiffrait respectivement a'environ 3, 22, 12 et 2%. La proportion relative de la diversite´ge´ne´tique perdue attribuable a'la de´rive ge´ne´tique due au hasard chez les porcs DC, HP, LC et LR s'e´tablissait respectivement a'74,5, 63,6, 72,9 et 60,0%. La taille efficace actuelle de la population de porcs DC, HP, LC et LR a e´te´estime´e a'72, 14, 36 et 125, respectivement. Par conse´quent, ce sont les porcs HP et LC qui ont perdu la plus grande diversite´et ces races devraient eˆtre juge´es prioritaires sur le plan de la conservation. Mots clé s: De´rive ge´ne´tique, taille efficace de la population 331 Can. J. Anim. Sci. Downloaded from pubs.aic.ca by University of Saskatchewan on 05/10/11 For personal use only. Can. J. Anim. Sci. Downloaded from pubs.aic.ca by University of Saskatchewan on 05/10/11 For personal use only.
doi:10.4141/cjas10002 fatcat:v4yobc6kezdnneht6ymhiq5d6m