Animal genetic resources conservation in the Netherlands and Europe: poultry perspective.

Increased global use of highly productive breeds of farm animals has been coupled to loss of genetic diversity in most species. In European countries, various governmental, non-governmental, and private organizations try to preserve genetic diversity of livestock in situ (e.g., by stimulating the use of indigenous, rare breeds by farmers; in nature reserves; or in noncommercial farms). In the case of poultry, maintaining in situ populations of the noncommercial (fancy) breeds largely relies on hobby farmers. In addition to in situ conservation, gene banks are being established for ex situ conservation. In at least 2 countries, France and The Netherlands, there are limited collections of frozen semen of rare poultry breeds. Since 2003, the CGN has started with a more systematic effort to collect, freeze, and store semen of indigenous Dutch poultry breeds. At present, the CGN gene bank contains semen of 11 Dutch rare poultry breeds. Also, CGN has performed research on the methodology for cryopreservation of fowl semen. This recent work was focused on finding a suitable replacement for glycerol, which is contraceptive in the hen, as a cryoprotectant. For reasons of hygiene and sample identification, we favored straw freezing, as opposed to the highly effective pellet freezing method. A significant interaction was found between cooling rate and cryoprotectant concentration. Best post-thaw sperm quality was obtained when combining 0.6 mol of dimethylacetamide/L with a cooling rate of +/- 200 degrees C/min. Inseminations twice per week with 0.3 billion sperm per insemination resulted in 97 and 88% fertilized eggs with fresh and frozen semen, respectively. In 2005, CGN has used this straw freezing method to extend the collection of poultry semen in the Dutch gene bank.