C9. Genetic resources for food and agriculture

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

 

Indicator Description

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 in-breeding 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).

Summary

 

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

Pig for pigs increased from 177 in 2000 to 230 in 2011, but decreased to 145 in 2016;

horsefor horses decreased from 179 in 2000 to 169 in 2011 and to 116 in 2016;

sheep for sheep increased from 228 in 2000 to 359 in 2011 and was little changed at 356 in 2016;

Cattle for cattle increased from 91 in 2000 to 196 in 2011 and to 308 in 2016; 

goat for goats the dataset starts in 2004 when it was 63, increasing to 73 in 2011 and to 89 in 2016; prior to 2004, effective population size could only be calculated for one breed. 

The average effective population sizes calculated between 2000 and 2016 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 2016, of the Native Breeds at Risk, two breeds of goat (Saanan, Toggenburg), three breeds of horse (Cleveland Bay Horse, Eriskay Pony, Suffolk), and one breed of cattle (Vaynol), had a Ne less than 50.  No breeds of sheep or pig had effective population sizes below the threshold in 2016.

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 2016.

 

Figure C9ai. Average effective population size (Ne) of Native Breeds at Risk, 2000 to 2016.

 

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 2016 values are based on four goat breeds, 11 pig breeds, 13 horse breeds, 27 sheep breeds, and 16 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. Data for 2015 and 2016 are provisional, hence the last part of the lines are shown as ‘dashed’.  It is expected that the provisional data can be confirmed in 2018 (see the technical document for details).
  3. Based on data in the UK Farm Animal Genetic Resources Breed Inventory published on 23 May 2017.  
  4. Historic data for some breeds of sheep and cattle are now available in the inventory published in 2017, affecting the series for these species.  As a result, this indicator is not directly comparable with the previous publication. 
  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 pale grey line is an average of all 88 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, 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

indicator improving
2004–2016

indicator improving
2011–2016

Increased (2016)

Pig breeds

2010 indicator stable2000–2016

2010 indicator declining
2011–2016

 

Decreased (2016)

 

Horse breeds

2010 indicator declining

2000–2016

2010 indicator declining
2011–2016

Decreased (2016)

Sheep breeds

indicator improving

2000–2016

2010 indicator stable2011–2016

Decreased (2016)

Cattle breeds

indicator improving
2000–2016

indicator improving
2011–2016

Increased (2016)

 

Download Fiche

Download Datasheet 

Download Technical background document

 

Last updated: August 2017

Latest data: 2016