Development of a genetic indicator of biodiversity for farm animals

Villanueva, Beatriz; Sawalha, R. M.; Roughsedge, T.; Rius-Vilarrasa, E.; Woolliams, John

doi:10.1016/j.livsci.2010.01.025

Cited by 18 publications

(11 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This was applied in the UK by Villanueva et al (2010) as a biodiversity indicator for the UK Government. Globally such activities are rare, and indeed there is no international standard for assessment of livestock genetic variation (Martyniuk et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

“…When groups are merged, for each species apart from goat at least one positive correlation has been found between N e (LD) or N e (DF) as the dependent variable, and N e (Wright) or N c (Table 2). Recalculating the regressions with the intercept set as zero (forcing the regression line through the origin) follows Villanueva et al (2010) in setting N e of an extinct breed as zero and yields empirically derived, predictive equations (Table 4). Perhaps different regression equations would be appropriate for different groups of breeds, but further investigation would seem to be premature until more comprehensive data matching N e estimates to breed census are available.…”

Section: Discussionmentioning

confidence: 99%

“…Responsibility for monitoring global conservation status has been assigned to the Food and Agricultural Organization (FAO) of the United Nations, whose global database, known as DAD-IS (http://dad.fao.org/) documents the numerical status of each country's livestock breeds. In some countries, including the UK Villanueva et al, 2010), national suites of biodiversity indicators include indices based not only on numerical status of breeds but also on the globally accepted measure of within-breed genetic diversity, namely effective population size N e . Maintenance of N e at, or above, 50 to 100 is a principle of breed conservation (Meuwissen, 2009).…”

Section: Introductionmentioning

confidence: 99%

“…Santiago and Caballero (1995) described from a theoretical basis, coupled with simulations, how N e can be deduced from N c in a population in which every individual is subject to selection. Predictive equations were used by Villanueva et al (2010) to deduce N e in breeds lacking pedigree records. The approach in the present study is, in contrast, purely empirical.…”

Section: Introductionmentioning

confidence: 99%

“…Studies reporting N e (DF) used bespoke software or other packages. Eight British sheep breeds whose N e had been deduced by predictive equations (Villanueva et al, 2010) were included in the N e (DF) data set. Total numbers of breeds of each species for which N e (DF) were known were as follows; cattle 130, sheep 85, horse 51, pig 44 and goat 11.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Effective population sizes in cattle, sheep, horses, pigs and goats estimated from census and herdbook data

Hall¹

2016

Animal

View full text Add to dashboard Cite

Accurate measures of effective population sizes ( N e ) in livestock require good quality data and specialized skills for their computation and analysis. N e can be estimated by Wright's equation N e = 4MF/( M + F) (M, F being sires and dams, respectively), but this requires assumptions which are often not met. Total census sizes N c of livestock breeds are collated globally. This paper investigates whether estimates of N e can be made from N c ; this would facilitate conservation monitoring. Some N e methodologies avoid the assumptions of Wright's equation and permit measurement, rather than estimation, of N e . Those considered here employ, respectively, linkage disequilibrium (LD) of single-nucleotide polymorphisms (yielding N e ( LD)), and genealogical analysis (rate of increase of inbreeding, DF), yielding N e (DF). Considering breeds of cattle, sheep, horses, pigs and goats for which N c and either N e ( LD) or N e ( DF) are known (totals of 203 breeds and 321 breeds, respectively), proportionality has been investigated between N c and these measures of N e . N e ( LD) was found to increase with N c , significantly in sheep and horses, less so in cattle, but not at all in pigs. N e ( DF) was correlated with log 10 ( N c ) in cattle, sheep and horses (53, 56, 43 breeds, respectively). N e ( LD) was correlated in cattle (73 breeds) and pigs (31 breeds) with the log 10 transformation of N e as calculated by Wright's equation.Further verification and refinement are needed, particularly of census data, but credible predictions of N e are obtainable by applying the following multipliers to log 10 ( N c ): cattle 17.61, sheep 97.72, horse 70.78. For cattle and pigs, multiplying log 10 ( N e (Wright)) by, respectively, 40.69 and 60.09, also gives credible predictions. Such census-based estimates of N e could in principle be generated by non-specialists and are likely to be suited to audits of conservation activity when financial resources or availability of data are limiting. The ratio N e /N c varied among species with an overall median value of 0.03, less than a tenth of that typically observed in wild mammals. Characteristics were also investigated of a distinct herdbook-based methodology, namely the development of Wright's equation to take into account variances of progeny numbers to yield what has been termed here N e (Hill). Comparison of these values with N e (Wright) could help to identify breeds with breeding structures conducive or inimical to genetic conservation. However, N e (Hill) requires breed-specific values for these variances, and this restricts its applicability.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%