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Analyses of genetic diversity in five C anadian dairy breeds using pedigree data
Author(s) -
Melka M.G.,
Stachowicz K.,
Miglior F.,
Schenkel F.S.
Publication year - 2013
Publication title -
journal of animal breeding and genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 51
eISSN - 1439-0388
pISSN - 0931-2668
DOI - 10.1111/jbg.12050
Subject(s) - inbreeding , genetic diversity , pedigree chart , breed , effective population size , biology , population , zoology , genetics , demography , sociology , gene
Summary The issue of loss of animal genetic diversity, worldwide in general and in C anada in particular, has become noteworthy. The objective of this study was to analyze the trend in within‐breed genetic diversity and identify the major causes of loss of genetic diversity in five C anadian dairy breeds. Pedigrees were analyzed using the software EVA (evolutionary algorithm) and CFC (contribution, inbreeding, coancestry), and a FORTRAN package for pedigree analysis suited for large populations ( PEDIG ). The average rate of inbreeding in the last generation analyzed (2003 to 2007) was 0.93, 1.07, 1.26, 1.09 and 0.80% for A yrshire, B rown S wiss, C anadienne, G uernsey and M ilking S horthorn, respectively, and the corresponding estimated effective population sizes were 54, 47, 40, 46 and 66, respectively. Based on coancestry coefficients, the estimated effective population sizes in the last generation were 62, 76, 43, 61 and 76, respectively. The estimated percentage of genetic diversity lost within each breed over the last four decades was 6, 7, 11, 8 and 5%, respectively. The relative proportion of genetic diversity lost due to random genetic drift in the five breeds ranged between 59.3% and 89.7%. The results indicate that each breed has lost genetic diversity over time and that the loss is gaining momentum due to increasing rates of inbreeding and reduced effective population sizes. Therefore, strategies to decrease rate of inbreeding and increase the effective population size are advised.