Criteria for the Recognition and Prioritisation of Breeds of Special Genetic Importance
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1 ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ Criteria for the recognition and prioritisation of breeds of special genetic importance L. Alderson Countrywide Livestock Ltd, 6 Harnage, Shrewsbury, Shropshire SY5 6EJ, United Kingdom Summary de races locales dans leur contexte international. Rare Breeds International a développé et appliqué un système qui The State of the World survey of animal surmonte ces problèmes, et qui coïncide avec genetic resources (SoWAnGR) has les critères appliqués par la FAO. Le système highlighted the necessity to reconcile the utilise trois critères: la distinction, varying systems applied by different l’adaptation locale, et la scarcité numérique; organisations for the identification and cette dernière est mesurée de préférence par categorisation of endangered breeds of le nombre de femelles enregistrées chaque livestock. Currently, many of these systems année plutôt que par le nombre de femelles are irreconcilable. In particular, there is a croisées. Le système est simple, précis et need to interpret national breed populations effectif, et se base sur des données globales, in the context of their international ce qui permet une interprétation plus efficace population. Rare Breeds International has des rapports SoW. developed and applied a system which overcomes these problems, and which Keywords: Endangered breeds, Prioritisation, coincides with criteria applied by FAO. The Characterisation, Adaptation, Distinctiveness, system utilises three criteria, namely Population. distinctiveness, local adaptation, and numerical scarcity. Numerical scarcity is measured preferentially by the number of Introduction annual female registrations rather than the number of breeding females. The system Procedures for the identification and embodies simplicity, accuracy and categorisation of endangered breeds of effectiveness, based on global data, and will livestock have developed inconsistently. enable more effective interpretation of Different systems are applied by various SoWAnGR reports. organisations involved with programmes for the conservation of animal genetic resources. This at least may cause difficulty and Résumé confusion when attempting to compare data, and at worst may yield misleading results L’enquête sur la Situation mondiale des from analytical studies. ressources génétiques animales (SoW) a souligné le besoin de standardiser les systèmes appliqués par les différentes organisations pour l’identification et la classification des races domestiques en danger. Souvent, certains de ces systèmes ne Paper presented at the joint RBI-EAAP workshop peuvent pas être standardisés. En particulier, held in Cairo, Egypt on 29 August 2002. il existe le besoin d’interpréter les populations ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ AGRI 2003, 33: 1-9 Recognition and priorisation of breeds 2 ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ The difficulties were addressed and Union for Conservation of Nature analysed in the Rachel Ella Nussbaum standards), and a different critical Memorial Lecture at the Rare Breeds population size applied to each species. International (RBI) Congress in 1994 In practice, the modifications proved too (Alderson, 1995), but only limited subsequent complex, and the system was applied mainly action has been taken. There is a need to on the simple criterion of number of implement more fully an agreed system registered purebred breeding females. The which will permit effective and rapid other factors (number of breeding units, exchange of information between number of unrelated sire lines, trends of international and national databases, and population, distance between major breeding which will give an accurate measurement of units) exert a significant influence on the the endangered status of each breed. The degree of endangeredness, but were objective of this paper was to establish a disregarded in the interests of simplicity. framework for an internationally acceptable procedure to evaluate the status of endangered breeds. Other NGO models Variations of the basic model were adopted Current Situation by rare breeds NGOs in other countries. For example, American Minor Breeds First model Conservancy (AMBC, later ALBC) segregated breeds on the basis of their national and international population into The earliest procedure to identify breeds four categories of vulnerability – critical, rare, worthy of support as endangered breeds was watch and study. Breeds also were formulated by the author in 1975 (Alderson categorised into four types, namely landrace, 1994). It evaluated breeds initially on an standardised, industrial and feral (Christman assessment of their status as a distinct and et al, 1997). Most of the endangered breeds in recognisable population, and then USA have their origin in the Old World, but categorised them by numerical criteria. This the introduction of the term ‘landrace’ was a procedure was applied in the United significant recognition of the importance of Kingdom and, with some minor native (indigenous, autochthonous) breeds, modifications and refinements, was used although it has potential for confusion with until 2001. the named ‘Landrace’ breeds of sheep and The principles embedded in this pig. procedure were based on genetic integrity, In Europe, the University of Hannover indicated by absence of recent introgression, followed a different line by attempting to and degree of vulnerability from either estimate the potential loss of genetic geographical limitations or numerical variability (Simon 1995). Greater emphasis scarcity. Critical population size was was placed on estimates of increase in calculated through a formula based on homozygosity (inbreeding), and effective mating ratio, reproductive rate and population size (Ne) was the favoured generation interval, but was modified by criterion. Ne is a valuable tool, but trends of population, number of distinct sire underestimates genetic erosion where lines, number of breeding units and selection intensity is high. Without modifying geographical distribution. Four priority factors it is accurate only when random categories were recognised namely ‘critical’, breeding is practised. Its value in commercial ‘endangered’, ‘vulnerable’ and ‘at risk’ or farm conditions is limited for this reason. (broadly compatible with International ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ Alderson 3 ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ A proposal from the Genetic Resources Evaluation of existing procedures Committee of European Association for Animal Production (EAAP, 2001/2) uses the 1. The major shortcoming with most systems number of breeding females as the basic is that data are not current, and in some criterion, but applies modifying factors cases not accurate. In some cases derived from the percentage of females used population figures are estimates, as a for purebreeding, trend in number of result of the difficulty of collecting breeding females, number of herds, and complex information. Comprehensive trend in number of herds, to calculate the current information is available only corrected number of breeding females. spasmodically. 2. It is clear that many breeds that are genetically important are excluded by the Governmental bodies procedures used by some organisations. This is evident from an analysis of breeds FAO used a standard population size for all of cattle in the United Kingdom (Table 3), species and initially set a limit of and results from the use of population size 10 000 breeding females. As a result of later as the dominant indicator of changes, the numerical criteria adopted by endangeredness. Numerical scarcity is not FAO were a maximum of 1 000 breeding the only factor which should determine females for endangered status, and prioritisation for recognition and support. 100 breeding females for critical status 3. There are fundamental species differences (Scherf, 2000). In Europe the criteria were derived especially from variation in length determined by population size throughout of breeding life, but also from mating EU rather than simply in the country of ratios and reproductive rate. These are origin. The limits ranged from 4 000 breeding recognised in the UK procedure and in females for cattle and equine breeds with the proposed EAAP system, but not in increasing populations to 9 000 breeding many others. females for sheep and goat breeds with 4. In most systems population size is declining populations. Current proposals assessed through the number of breeding within EU favour a return to a criterion of a females. This may not be the best criterion. regional (European) breed population of The purpose of prioritisation is to assess breeding females of 7 500 cattle, the vulnerability of a breed. The number 10 000 sheep and goats, 5 000 horses and of breeding females has provided useful ponies, 15 000 pigs and 25 000 poultry guidance but it has shortcomings. For (Regulation 445/2002 Article 14). example, not all organisations carry out a Cultural and socio-economic factors in census of breeding animals, some females developing countries demand the application may be used in crossing programmes, not of different criteria. There is rarely a system all females are registered, not all females of individual identification or registration of may be bred each year, and not all animals and research workers at ILRI have progeny may be registered. The attempt developed a concept of ‘extinction by Hannover to base prioritisation on