Genetic diversity is the key to all genetic progress, past and future. Over the last 10,000 years, poultry was domesticated first from the wild jungle fowl, then in the last 1,000 years into standard breeds. In the last century, those breeds have been further reduced into a few commercially produced types. These lines have since been strongly selected for both growth and egg production among other traits. During this process, genetic variability has been lost at each step. Important issues include: ¿How much variability has been lost¿ and ¿Is there adequate variability to meet future challenges, such as new diseases"? To achieve this goal, a panel of 2551 informative SNPs were genotyped on 2580 individuals including 1440 commercial birds. Allele loss was assessed by determining the relationship with inbreeding, and through the use of SNP ¿weights¿ that correct for ascertainment bias and avoid the need to extrapolate from the inbreeding coefficient. The methods presented are general and could be used to assess loss of biodiversity based on SNP panels. Results indicate that sampled broiler lines of multiple companies have lost between 55%-70% of allelic diversity while sampled layer lines of one commercial layer company have lost between 80%-90% of allelic diversity. However, Insillico crosses among lines show that many of the lost alleles can be found in other lines within the company resulting in true loss across the industry of approximately 50%. However, the alleles lost were primarily those that were rare; it is not known if rare vs. common alleles are more or less likely to be important for response to new challenges. These allele may still exist in standard breeds or wild birds, but the issue remains of how to assess the importance of those alleles to phenotype, and/or how to move them into commercial populations without introducing unwanted alleles.
|Publication status||Published - 2008|
|Event||Plant and Animal Genome XVI Conference - |
Duration: 12 Jan 2008 → 16 Jan 2008
|Conference||Plant and Animal Genome XVI Conference|
|Period||12/01/08 → 16/01/08|