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C9a. Animal genetic resources – effective population size of Native Breeds at Risk

i.  Goat breeds

ii.  Pig breeds

iii. Horse breeds

iv. Sheep breeds

v. Cattle breeds

Type: State / Benefit Indicator

 

Introduction

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).

Key results

The average effective population size of the native breeds at risk included in this indicator:

Pig icon for pigs decreased from 177 in 2000 to 157 in 2015 and to 129 in 2020;

horse icon for horses decreased from 178 in 2000 to 94 in 2015 and to 75 in 2020;

sheep icon for sheep increased from 245 in 2000 to 361 in 2015 and to 402 in 2020;

cattle icon for cattle increased from 121 in 2000 to 287 in 2015 and to 334 in 2020;

goat icon for goats the dataset starts in 2004 when it was 63, increasing to 83 in 2015 and decreasing to 81 in 2020; prior to 2004, effective population size could only be calculated for one breed.

The average effective population sizes calculated between 2000 and 2020 for the native breeds at risk of goats, pigs, horses, sheep and cattle were each above 50, the figure set by the United Nations Food and Agriculture Organisation as a threshold for concern. However, in 2020, of the Native Breeds at Risk, one breed of goat (Old English Goats), four breeds of horse (British Percheron / Percheron, Cleveland Bay Horse, Eriskay Pony, and Suffolk Punch), one breed of sheep (Devon and Cornwall Longwool) and two breeds of cattle (Northern Dairy Shorthorn, Vaynol), had a Ne less than or equal to 50. No breeds of pig had effective population sizes below the threshold in 2020.

There has been no reported UK extinction of any breeds of goats, pigs, horses, sheep or cattle since 1973.

Figure C9ai. Average effective population size (Ne) of Native Breeds at Risk, 2000 to 2020.

A line chart showing the average effective population size of native breeds at risk in the UK. There are individual lines (measures) in the chart for sheep, cattle, pigs, goats, horses and all breeds from 2000 to 2020. The chart shows that the average effective population sizes calculated between 2000 and 2020 for the native breeds at risk of goats, pigs, horses, sheep and cattle were each above 50, however there are native breeds within these measures which are at risk.

Notes:

  1. The number of breeds included in the indicator varies year by year as a result of data availability for both sires and dams (data for both are needed to calculate effective population size). The maximum number of breeds included in each measure is shown in brackets after the species name in the legend. The annual data collection for the 2020 data accounts for 85% of the total breeds and these are for six goat breeds, 11 pig breeds, 13 horse breeds, 34 sheep breeds, and 22 cattle breeds. Further details of how many breeds are included in each year can be found in the technical background document and the datasheet.
  2. Some of the breed data are collected through the three-yearly survey (most recently published October 2018). The next triennial survey will provide additional data for 2018, 2019 and 2020. Hence the last part of the lines are provisional, and shown as ‘dashed’.
  3. Based on data published in the UK Farm Animal Genetic Resources Breed Inventory published on 23 June 2021. https://www.gov.uk/government/statistics/uk-farm-animal-genetic-resources-fangr-breed-inventory-results
  4. Over the course of time, data for some breeds has been revised. In 2021, four breeds of NBAR cattle (Aberdeen Angus (Original Population); British Friesian (Original); Dairy Shorthorn (Original Population); and Hereford Traditional / Original) were merged with their associated larger non-NBAR populations, this was to ensure there was no duplication of data for these breeds. In addition, one sheep breed (Badger Face Welsh (Torddu and Torwen)) was split into two separate breeds, resulting in a recalculation of the entire data series. Therefore, this indicator is not directly comparable with previous publications.
  5. The dotted black line shows effective population size (Ne) equal to 50; the level set by the United Nations Food and Agriculture Organisation as a threshold for concern. The dark grey line is an average of all 86 Native Breeds at Risk for which Ne could be calculated; this is included to provide context but is not assessed.

Source: British Pig Association; Defra; Grassroots Systems Ltd.; Rare Breeds Survival Trust; and participating breed societies.

Assessment of change in effective population size of Native Breeds at Risk

 

Long term

Short term

Latest year

Goat breeds

Improving2004–2020

Little or no overall change2015–2020

Decreased (2020)

Pig breeds

Deteriorating2000–2020

Deteriorating2015–2020

Decreased (2020)

Horse breeds

Deteriorating2000–2020

Deteriorating2015–2020

Decreased (2020)

Sheep breeds

Improving2000–2020

Improving2015–2020

Decreased (2020)

Cattle breeds

Improving2000–2020

Improving2015–2020

Increased (2020)

Note: Long- and short-term assessments are based on a 5% rule of thumb. Where possible, the base years for these assessments use a three-year average. See Assessing Indicators.

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Further detail

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 Resources (FAnGR) Committee breed inventory was first published in 2014 with information for pigs, goats and horses, and was expanded in 2015 to include sheep and cattle.

In the inventory published in 2021 (data for 2020), all six native breeds of goats, all 11 native breeds of pigs, 13 of 19 native horse breeds, 48 of 61 native sheep breeds, and 23 of 30 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).

For pigs, data to calculate effective population size is available for all years for all breeds included in the indicator (from 2000 to 2020 for 11 breeds). However, for goats, horses, sheep and cattle, the number of breeds contributing to the indicator increases over time as more data becomes available (for details see the technical document).

As all pedigree animals need to be registered with their respective society to receive their pedigree certificate, the breed society records are comprehensive. Data in the inventory is sourced from individual breed society records and is drawn from two sources. To maximise efficiency in data collection, central database suppliers who maintain the breed society databases supply the data to the Defra Farm Animal Genetic Resources team. This is the main source of data used in the indicator and breed societies have given their permission for these companies to supply the data to Defra every year for this exercise. Additional data is collected through a three-yearly survey of individual breed societies, which provides further breed data. The most recent triennial survey was published in October 2018, providing breed data for 2015, 2016 and 2017. The next triennial survey will provide data for 2018, 2019 and 2020. This means that while most of the breed data for the indicator is published on an annual basis, some additional data becomes available on a three-yearly basis through the breed society survey. The triennial survey receives data from about two thirds of the breed societies contacted and therefore there are some breeds for which data is not available and thus are not included in the indicator.

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 inbreeding and risk of loss of genetic diversity. A larger effective population size implies a lower risk of inbreeding and higher genetic diversity.

The assessment of change for the indicator was made by applying a 5% rule of thumb. 5% was chosen to recognise the human element in the choice of which sires breed with which dams (which is not random for non-feral breeds), and because this level has already been chosen by the Rare Breeds Survival Trust to identify changes from the previous year’s Watchlist publication. The arithmetic mean of the first three years of the data series for each species was compared with the most recent value (2020), to determine the assessment for the long-term trend. An arithmetic mean of the year five years prior in the time-series and the year either side of this (2014, 2015, 2016) was calculated to compare with the most recent value (2020) to assess the short-term trend. It should be noted that single year variations in the measures are not hugely meaningful, due to the human element in which sires breed with which dams.

The United Nations Food and Agriculture Organisation (FAO) recommends a minimum effective population size (Ne) of at least 50 individuals to reduce the rate of inbreeding to less than 1% and ensure the long-term survival of a breed. Figure C9ai shows that, on average, all five species have Ne greater than 50. However, examination of the data for the individual breeds reveals (Figure C9aii) that there are a small number of breeds with Ne less than or equal to 50 in many years. The breeds which are represented in Figure C9aii may change from year to year; see the downloadable datasheet for details. In 2020, one breed of goat (Old English Goats), four breeds of horse (British Percheron/Percheron, Cleveland Bay Horse, Eriskay Pony, and Suffolk Punch), one breed of sheep (Devon and Cornwall Longwool) and two breeds of cattle (Northern Dairy Shorthorn and Vaynol), had an Ne less than or equal to 50. No breeds of pig had effective population sizes below the threshold in 2020.

In 2021, the FAnGR Committee took the decision to merge four breeds of NBAR cattle (Aberdeen Angus (Original Population); British Friesian (Original); Dairy Shorthorn (Original Population); and Hereford Traditional / Original) with their associated larger non-NBAR populations. This was to ensure there was no duplication of data for these breeds. It was determined that the merging of these breeds was only for the purpose of the national inventory, should be applied to the entire indicator data series, and does not represent removal of these breeds from the BAR or NBAR lists. Furthermore, in the 2021 Breed Inventory, the NBAR sheep breed, Badger Face Welsh (Torddu and Torwen), has been split into two separate breeds (Badger Face Welsh (Torddu) and Badger Face Welsh (Torwen)). The original combined version has been removed, and the two split breeds added to the indicator. As a consequence of these changes to cattle and sheep, the entire data series has been recalculated and the 2021 version of the indicator is not directly comparable with previously published versions. Please refer to the technical background document for further details. These are also documented in the Breed Inventory Results (Excel datasheet) published on 23 June 2021: https://www.gov.uk/government/statistics/uk-farm-animal-genetic-resources-fangr-breed-inventory-results.

Five individual bar charts for goats, pigs, horses, sheep and cattle. Each bar chart shows the number of native breeds at risk for each species with an effective population size of less than or equal to 50, for the period between 2000 and 2020. Refer to the indicator text for further details of the trends.

Note: Based on data in the UK Farm Animal Genetic Resources Breed Inventory published on 23 June 2021.

Source: British Pig Association; Defra; Grassroots Systems Ltd.; Rare Breeds Survival Trust; and participating breed societies.

goat icon Goats

The average Ne of the six goat breeds in the indicator is above 50 and has changed little in the short term. Three of the six breeds increased. Bagot increased in Ne from 48 in 2000 to 112 in 2020. Golden Guernsey increased in Ne from 197 in 2004 to 393 in 2020. Saanen has increased slightly in Ne from 44 in 2004 to 55 in 2020; the highest point in the data range (2004 to 2020) was in 2017 when the Ne was 71. Toggenburg has remained stable. Old English Goats have been added to the dataset for the first time, with an Ne of eight recorded in 2020.

horse icon Horses

Nine of the 13 horse breeds in the indicator have had declines in Ne, showing a long-term decrease, and this is matched by an overall short-term decline in the average Ne . The Eriskay pony has had an effective population size of less than 50 each year since 2000 with the Ne for 2016 and 2018 being four. Since 2001 when it joined the indicator, the Suffolk Punch has had an Ne of less than 50 every year but one (2009, when the value was 53). The Ne for New Forest Pony has declined from 716 in 2000 to 251 in 2020. Since 2002 when it joined the indicator, the Cleveland Bay Horse has had an Ne of 50 or less, for 10 of the 19 years it has been included, with the lowest effective population size being 31 in 2020. The Ne for the Clydesdale Horse increased from 119 in 2002 to 154 in 2020, an increase of 29%. The Ne for British Percheron/Percheron, for which there are only eight years’ worth of data, has decreased to 10 in 2020.

pig icon Pigs

No NBAR pig breeds have had an Ne of less than 50 since 2003. There was a dip in pig numbers in 2001 as a result of foot and mouth disease, and a peak in 2007 as a result of breeding for export. Six pig breeds have increased in Ne since 2000 (the biggest increase was for Oxford Sandy and Black) and four breeds have decreased – the largest decrease (-89%) was for Landrace from 652 in 2000 to 59 in 2020. Large Black has remained stable over this period.  

sheep icon Sheep

As with pigs, there was a dip in numbers in 2001 as a result of foot and mouth disease. The time-series for these breeds varies in length; of the 27 breeds with at least 10 years of data, 20 breeds have had an increase in Ne (for example, Boreray, Castlemilk Moorit, Hampshire Down, Kerry Hill, Leicester Longwool, and Shropshire) and five a decrease (Black Welsh Mountain, Cotswold, Devon and Cornwall Longwool, Whitefaced Woodland and Wiltshire Horn), with two breeds remaining stable (Manx Loaghtan and Wensleydale). There has been a strong increase in the Ne for Boreray, from a low of 15 in 2001 to 199 in 2020. There are six years of data (2012 to 2017) for Cambridge, but Ne is low (ranging between 35 and 42) for all six years.

cattle icon Cattle

As with sheep, the time-series for the breeds contributing to the indicator varies in length. Of the 15 breeds with at least 10 years of data, 12 have increased (for example, Belted Galloway, Lincoln Red including Lincoln Red (Original), and Luing) and two breeds have decreased (Galloway and Gloucester), while one has remained stable (British White). The effective population size of Vaynol has been in single figures for 10 of the 13 years it has been included in the indicator, apart from 2016 where it was 10; 2017 where it was 14; and 2019 where it was 16. The effective population size of Chillingham for which there are only three years of data (2012 to 2014) is four for each of those years.

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Relevance

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 or improve existing 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).

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Background

The UK is home to some of the richest and most diverse farm animal genetic resources in the world, with approximately 700 breeds including cattle, sheep, goats, pigs, horses and ponies and poultry; the UK contains more than 9% of the total of global livestock breeds. There are some 200 native breeds according to the definition adopted by the UK Farm Animal Genetic Resources (FAnGR) Committee, the majority of which are considered to be “at risk”. A list of known breeds in the UK is given in Appendix 2 of the 2012 UK Country Report on Farm Animal Genetic Resources and in the Annex of the 2010 Poultry in the UK report. Defra and its FAnGR Committee monitor the status of UK breeds to determine if they are native, exotic, at risk or not; and ensure that eligible species/breeds:

  • Are offered potential protection in an outbreak of an exotic disease (as far as possible within the constraints of controlling the disease).
  • Have potential access to a grazing supplement under agri-environment schemes.

Many of the UK’s habitats that are now valued for their biodiversity were created by, or for, farm animals. These habitats include various types of upland and lowland grasslands and heathlands, hay meadows and pasture-woodlands. Other habitats, such as sand dunes, salt marshes and even woodlands may also benefit from light grazing. If these habitats are not grazed they may lose their special conservation value as they become invaded and eventually dominated by scrub and trees through the process of ecological succession.

Although it is not possible to measure the genetic variation in all traits of interest, the average rate of loss in genetic variation can be estimated, since this rate can be described by calculating the ‘effective population size’.

The UK Farm Animal Genetic Resources (FAnGR) Breed Inventory is an electronic monitoring system. It was first published by Defra in July 2014 and updated annually since then. The monitoring system contains data on the status and trends in the domestic pig, goat, horse, sheep and cattle farm animal genetic resources with continuous data from 2000 to 2020 for around 100 NBAR breeds which are present in the UK. More recently, the electronic monitoring system for FAnGR is collecting more information and more regularly, which is leading to greater completeness of data provided in non-triennial years.

Defra and the Farm Animal Genetic Resources Committee will continue to monitor populations of UK livestock breeds regularly; the list of Breeds considered to be at Risk is kept under annual review using the monitoring data collected, with Breeds at risk potentially eligible for protection in an outbreak of an exotic disease (within the constraints of controlling the disease).

Supplementary information from the Rare Breeds Survival Trust Watchlist

The Rare Breeds Survival Trust (RBST) works to conserve and protect the United Kingdom’s rare native breeds of farm animals from extinction as a resource for future generations and for the benefit of agriculture. Between 1900 and 1973, the United Kingdom lost 26 of its native breeds. This was caused by changing farming methods and a much more intensive approach to food production. Since the formation of the Trust in 1973 no other native livestock breed has become extinct in the UK.

The RBST publishes an annual watchlist, which highlights changes in breed population trends. The 2021-22 Watchlist has been compiled using a new methodology, based on effective population size (previously the number of registered females was used) and taking into account the degree of inbreeding. Thus this approach is now more comparable to that used in this indicator. The Watchlist now categorises ‘Priority’ and ‘At Risk’ breeds for sheep, cattle, equine, pigs, goats and poultry, as well as listing ‘UK Native Breeds’ and ‘Irish Breeds in the UK’.

Within the Priority and At Risk categories, the 2021-22 Watchlist includes 28 breeds of sheep, 14 cattle, 11 pigs, four goats and 12 horse breeds.

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Goals and Targets

Aichi Targets for which this is a primary indicator

Strategic Goal C. To improve the status of biodiversity by safeguarding ecosystems, species and genetic diversity.

Aichi Target 13

Target 13: By 2020, the genetic diversity of cultivated plants and farmed and domesticated animals and of wild relatives, including other socio-economically as well as culturally valuable species, is maintained, and strategies have been developed and implemented for minimizing genetic erosion and safeguarding their genetic diversity.

Aichi Targets for which this is a relevant indicator

Strategic Goal C. To improve the status of biodiversity by safeguarding ecosystems, species and genetic diversity.

Aichi Target 12

Target 12: By 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.

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Reference Title
Defra UK National Action Plan on Farm Animal Genetic Resources (2006) (PDF, 1.3Mb)
Defra Poultry in the UK (PDF, 3.5Mb)
Defra  UK Country Report on Farm Animal Genetic Resources 2012
Defra   UK Breeds at risk list
Defra   UK Farm Animal Genetic Resources (FAnGR): breed inventory results 2020
Defra   Previous indicator, first published in 2009 Research Report: UK Biodiversity Indicators – development of an indicator of genetic diversity in selected farm breeds (WC0717)  (search term = WC0717) Indicator fiche in The National Archives
European Farm Animal Biodiversity Information System (EFABIS) UK page Note: Statistical data in the UK EFABIS database is automatically carried over to the clone database systems at the European level and global levels.
Rare Breeds Survival Trust Rare Breeds Survival Trust Watchlist
Food and Agriculture Organisation of the United Nations Domestic Animal Diversity Information System (DAD-IS)
Food and Agriculture Organisation of the United Nations Management of small populations at risk

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Downloads

Download the Datasheet and Technical background document from JNCC's Resource Hub.

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Last updated: October 2021

Latest data: 2020

Please note this page was republished on 3 March 2022 following a minor amendment to clarify the approach taken regarding the merging of cattle breed data.

This content is available on request as a pdf in non-accessible format. If you wish for a copy please go to the enquiries page.

Categories:

UK Biodiversity Indicators 2021

Published: .

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