The degree to which a breed is exposed to becoming extinct, i.e. its degree of endangerment (DE), is an essential information to orient conservation policies. Assessing DE properly is a difficult task, as numerous factors are involved. Several methods are currently used in Europe and the paper first discusses the development of some objective criteria to promote the creation of a uniform system. Both demographic and genetic aspects of population decline are considered. It is proposed to estimate the number of years needed to reach a critical population size, which is also a measure of time available to evaluate options and undertake action before extinction. Thresholds of endangerment for both the demographic and genetic aspects are discussed. In addition, the population growth rate of 110 European cattle breeds is analysed. Growth rate is normally distributed with a mean of 1.00 (S.D. 0.09, range 0.77-1.27). Population size at the beginning of the analysed period and country of breeding affect growth rate significantly.
Criteria to assess the degree of endangerment of livestock breeds in Europe / G.C. Gandini, L. Ollivier, B. Danell, O. Distl, A. Georgudis, E. Groeneveld, E. Martiniuk, J. van Arendonk, J. Woolliams. - In: LIVESTOCK PRODUCTION SCIENCE. - ISSN 0301-6226. - 91:1-2(2004), pp. 173-182. [10.1016/j.livprodsci.2004.08.001]
Criteria to assess the degree of endangerment of livestock breeds in Europe.
G.C. GandiniPrimo
;
2004
Abstract
The degree to which a breed is exposed to becoming extinct, i.e. its degree of endangerment (DE), is an essential information to orient conservation policies. Assessing DE properly is a difficult task, as numerous factors are involved. Several methods are currently used in Europe and the paper first discusses the development of some objective criteria to promote the creation of a uniform system. Both demographic and genetic aspects of population decline are considered. It is proposed to estimate the number of years needed to reach a critical population size, which is also a measure of time available to evaluate options and undertake action before extinction. Thresholds of endangerment for both the demographic and genetic aspects are discussed. In addition, the population growth rate of 110 European cattle breeds is analysed. Growth rate is normally distributed with a mean of 1.00 (S.D. 0.09, range 0.77-1.27). Population size at the beginning of the analysed period and country of breeding affect growth rate significantly.
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