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UK Biodiversity Indicators 2021. Indicator C9a – Animal genetic resources (effective population size of Native Breeds at Risk) 2021

Corporate UK Biodiversity


These documents support indicator C9a – Animal genetic resources (effective population size of Native Breeds at Risk). The documents include a datasheet and technical background document.

Genetic diversity is an important component of biological diversity. Rare and native breeds of farm animals are part of our cultural heritage, are often associated with traditional land management required to conserve important habitats, and may have genetic traits of value to future agriculture. The genetic diversity in UK breeds can be assessed by the effective population size (Ne), which accounts for the total number of animals in a population and the relative numbers of sires and dams (male and female parents). A low effective population size signifies a greater likelihood of inbreeding and risk of loss of genetic diversity.

This indicator shows the change in the average effective population sizes for breeds of goats, pigs, horses, sheep and cattle classified by the UK Farm Animal Genetic Resources Committee as Native Breeds at Risk (NBAR).

Please note the technical background document was republished in March 2022 following a minor amendment to clarify the approach taken regarding the merging of cattle breed data.

These resources may not be fully accessible for all users. If you need a copy of any of these resources in a different or more accessible format, please get in touch.

Resource type Publication

Topic category Environment

Reference date 2021·10·20

Department for Environment, Food and Rural Affairs, UK. 2021. UK Biodiversity Indicators 2021.

The UK Biodiversity Indicators were first published in 2007. They were created to provide a measure for reporting on the UK’s progress towards meeting international biodiversity goals and targets. The indicators were comprehensively reviewed during 2011 and 2012 to ensure they continued to be based on the most robust and reliable available data, and remained relevant to the new international goals and targets developed in 2010 and 2011.

Responsible organisation
Communications, JNCC distributor

Limitations on public access No limitations

Use constraints Released under the Open Government Licence v3.0. Attribution statement "Contains public sector information from Defra, licenced under the Open Government Licence v3.0"

Metadata date 2022·03·03

Metadata point of contact
Communications, JNCC

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