In situ preservation: a suggestion on conservation of animal genetic resources
W.ChanghSin
Biotehnologija u Stocarstvu 13(3/4): 41-48
1997
Accession: 003169609
The world-wide crisis in breed resources, due to a nearly exhausted gene pool, has been caused by the predominant use in developed countries of breeds with high economic potential (for pigs, Large White and Landrace in Europe and these plus Duroc and Hampshire in North America; for dairy cattle Holstein world-wide; for fowls White Leghorn-derived hybrids for egg production and White Plymouth Rock plus White Cornish-derived hybrids for meat production), the undiscriminating use of foreign breeds to the detriment of indigenous breeds in developing countries, and the lack of conservation of indigenous breeds. The minimum size of population needed to conserve a genetic resource was estimated for various levels of inbreeding and different generation intervals. The ratio between the effective population size and generation interval ranged from 480 for a generation interval of 1 year to 25 for a generation interval of 20 years. Generation intervals considered were 8 years for horses, 5 for cattle, 4 for wool sheep and goats, 3 years for meat sheep, 2.5 years for pigs and 1.5 years for poultry. Setting up breed resource farms is discussed; it is suggested that to be effective these would require 60 males and 300 females for small animal species and 30 males and 150 females for large animals. An example is given of the conservation of a fowl breed-the Beijing Oil.