This spreadsheet is the underlying data for the biodiversity indicator C9a, Animal genetic resources â effective population size of Native Breeds at Risk.
Genetic diversity is an important component of biodiversity. The UK genetic diversity indicator focuses on the diversity of Native Breeds at Risk of a number of farm animal species (cattle, sheep, goats, horses and pigs). Genetic diversity in livestock breeds is important for a number of reasons. Aside from their cultural importance, local adaptation and links to breed specific products, native or rare livestock breeds provide a resource from which to develop new breeds.
UK farm animal genetic resource is a key asset in economic, environmental, social and cultural terms. Native breeds of farm animals are often associated with traditional land management required to conserve important habitats. The indicator is also relevant to the commitments on conservation of native breeds in the UK National Action Plan on Farm Animal Genetic Resources (FAnGR).
The indicator shows the change in the average effective population sizes (Ne) for breeds of goats, pigs, horses, sheep and cattle classified by the UK Farm Animal Genetic Resources Committee as Native Breeds at Risk (NBAR). The UK Farm Animal Genetic Resource (FAnGR) Committee breed inventory was first published in 2013 with information for pigs, goats and horses, and was expanded in 2014 to include sheep and cattle; though it should be noted that there are currently no data for a number of breeds. In the 2014 inventory, all five native breeds of goats, all 11 native breeds of pigs, 15 of 20 native horse breeds, 46 of 59 native sheep breeds, and 29 of 38 native cattle breeds were classified as NBAR (for definitions of native breeds, and native breeds at risk, see Appendix 1 of the UK Country Report on Farm Animal Genetic Resources 2012). Of the native breeds classified as at risk, data for 12 native cattle breeds at risk, 24 sheep, two horses and one goat were not available in 2014, or for earlier years, and therefore effective population size could not be calculated for these breeds.
Effective population size is a calculation which takes account of the total number of animals in a population and the relative number of sires and dams (male and female parents). A low effective population size signifies a greater likelihood of in-breeding and risk of loss of genetic diversity. A larger effective population size implies a lower risk of inbreeding and higher genetic diversity.
This is one of a suite of 24 UK biodiversity indicators published by JNCC on behalf of Defra; the latest publication date was 19 January 2016 - for indicator C9a the latest data are for 2014. The supporting technical document details the methodology used to create the indicator.