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Pedigree analysis of the Nilagiri sheep of South India

Published online by Cambridge University Press:  13 September 2013

R. Venkataramanan ,
A. Subramanian ,
S.N. Sivaselvam ,
T. Sivakumar ,
C. Sreekumar ,
R. Anilkumar  and
M. Iyue
R. Venkataramanan*
Affiliation:
Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600 051, India
A. Subramanian
Affiliation:
Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600 051, India
S.N. Sivaselvam
Affiliation:
Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600 051, India
T. Sivakumar
Affiliation:
Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600 051, India
C. Sreekumar
Affiliation:
Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600 051, India
R. Anilkumar
Affiliation:
Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600 051, India
M. Iyue
Affiliation:
Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600 051, India
*
Correspondence to: R. Venkataramanan, Post Graduate Research Institute in Animal Sciences, Kattupakkam, Kancheepuram District, Chennai, Tamil Nadu 603 203, India. email: venkyvet@gmail.com
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Summary

The Nilagiri sheep is a dual utility (fine wool and meat), native to the Nilagiri hills of Tamil Nadu. It is known for its adaptability to high altitude and low input system of rearing. At present, this breed is endangered with less than a thousand numbers existing, of which about 50 percent is maintained at Sheep Breeding Research Station, Sandynallah. Efforts are on to conserve the breed in-situ. Generation interval (GI), pedigree completeness level, inbreeding coefficient (F), average relatedness (AR), effective population size (Ne), and effective number of founders (fe) and ancestors (fa) were studied for the breed. Pedigree analysis was carried out using data available at the research station on 5 051 animals from 1965 onwards using ENDOG ver. 4.8. Higher values of pedigree completeness (more than 80 percent for 5th generation), balance in percent of ancestors between sire and dam pathways and higher equivalent complete generations (7.12) for the reference population were indicative of the depth in pedigree. The GI, F, and AR were 3.36 years, 2.17 and 3.45 percent, respectively. Ne based on maximum number of generations and individual increase in inbreeding was 298.83 and 97.25, respectively. fe and fa were 59 and 41, respectively, for the reference population. F was far from critical values of inbreeding and fe/fa ratio indicated absence of stringent bottlenecks. The effective population size was on the higher end of the range reported for endangered sheep breeds. The knowledge on genetic diversity and effective population size coefficients would support the cause of conservation.

Résumé

Les moutons Nilagiri, bétail à double aptitude (laine fine et viande), sont originaires des montagnes Nilagiri du Tamil Nadu. Ces animaux sont réputés pour leur capacité d'adaptation aux altitudes élevées et aux systèmes d'élevage à faible intensité d'intrants. Avec moins d'un millier de têtes recensées, dont environ la moitié est maintenue à la Station de Recherche en Sélection d'Ovins de Sandynallah, la race est à présent menacée. Des efforts se réalisent pour la conservation in vivo de la race. L'intervalle générationnel (GI), le niveau de complétude de la généalogie, le coefficient de consanguinité (F), la parenté moyenne (AR), la taille effective de la population (Ne) et le nombre effectif de fondateurs (fe) et d'ancêtres (fa) ont été étudiés pour la race. L'analyse de généalogie a été menée avec des données, de 1965 en avant, disponibles à la station de recherche pour un total de 5 051 animaux, en utilisant ENDOG ver. 4.8. Des valeurs de complétude de la généalogie élevées (plus de 80 pour cent sur la cinquième génération), l'équilibre dans les pourcentages d'ancêtres entre lignes paternelles et maternelles et un nombre élevé de générations complètes équivalentes (7,12) pour la population de référence sont signe de la profondeur de la généalogie. GI, F et AR ont été de 3,36 ans, 2,17 pour cent et 3,45 pour cent, respectivement. La Ne basée sur le nombre maximal de générations et l'augmentation individuelle de la consanguinité a été de 298,83 et 97,25, respectivement. Pour ce qui est de fe et fa, les résultats ont été, respectivement, de 59 et 41 pour la population de référence. La valeur de F a été loin d'être critique et le rapport fe/fa a indiqué une absence de goulots d'étranglement sévères. La taille effective de la population s'est située sur l'extrême supérieur de la plage de valeurs rapportées pour les races ovines menacées. Les connaissances en diversité génétique et l'appréciation des coefficients de la taille effective de la population serviraient à soutenir la cause de la conservation.

Resumen

El ganado ovino Nilagiri, de aptitud doble (lana fina y carne), es oriundo de los montes Nilagiri de Tamil Nadu. Estos animales son conocidos por su capacidad de adaptación a altitudes elevadas y a sistemas de cría con bajos insumos. En la actualidad, esta raza está amenazada, quedando menos de un millar de ejemplares censados, de los cuales cerca de la mitad se mantienen en la Estación de Investigación en Mejora de Ganado Ovino de Sandynallah. Se están realizando esfuerzos para la conservación in situ de la raza. Se han estudiado, para la raza, el intervalo generacional (GI), el nivel de compleción del pedigrí, el coeficiente de endogamia (F), el parentesco medio (AR), el tamaño efectivo de población (Ne) y el número efectivo de fundadores (fe) y ancestros (fa). El análisis de genealogía fue llevado a cabo con datos, de 1965 en adelante, disponibles en la estación de investigación para un total de 5 051 animales, usando ENDOG ver. 4.8. Valores altos de completitud del pedigrí (más del 80 por ciento para la quinta generación), el equilibrio en el porcentaje de ancestros entre vías paternas y maternas y un elevado número de generaciones completas equivalentes (7,12) para la población de referencia son indicativos de la profundidad de la genealogía. El GI, F y AR fueron, respectivamente, de 3,36 a|ños, 2,17 por ciento y 3,45 por ciento. El Ne basado en el número máximo de generaciones y el incremento individual en consanguinidad fue de 298,83 y 97,25, respectivamente. Los resultados de fe y fa fueron de 59 y 41, respectivamente, para la población de referencia. El valor de consanguinidad F estuvo lejos de ser crítico y el ratio fe/fa indicó ausencia de cuellos de botella severos. El tamaño efectivo de la población se situó en el extremo superior del intervalo referido para razas ovinas amenazadas. El conocimiento de la diversidad genética y de los coeficientes del tamaño efectivo de población sería de ayuda para la causa de la conservación.

Keywords

pedigree analysisNilagiri sheepeffective population sizeinbreedingrelatednessanalyse généalogiquemoutons Nilagiritaille effective de la populationconsanguinitéparentéanálisis de genealogíaovejas Nilagiritamaño efectivo de la poblaciónconsanguinidadparentesco
Type
Research Article
Information
Animal Genetic Resources/Resources génétiques animales/Recursos genéticos animales , Volume 53 , December 2013 , pp. 11 - 18
Copyright
Copyright © Food and Agriculture Organization of the United Nations 2013 

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References

Alderson, G.L.H. 1992. A system to maximize the maintenance of genetic variability in small populations. In Alderson, L. & Bodo, I. (eds) Genetic Conservation of Domestic Livestock II. CABI, Wallingford, UK, pp. 18–29.Google Scholar
Bhatia, S. & Arora, R. 2005. Biodiversity and conservation of Indian sheep genetic resources – an overview. Asian-Australasian Journal of Animal Science 18: 1387–1402.CrossRefGoogle Scholar
Bijma, P. & Wooliams, J.A. 2000. Prediction of rates of inbreeding in populations selected on best linear unbiased prediction of breeding value. Genetics 156: 361–363.Google Scholar
Boichard, D., Maignel, L. & Verrier, E. 1997. The value of using probabilities of gene origin to measure genetic variability in a population. Genetics Selection Evolution 29: 5–23.CrossRefGoogle Scholar
Cassell, B.G., Adamec, V. & Pearson, R.E. 2003. Effects of incomplete pedigree on estimates of inbreeding and inbreeding depression for days to first service and summit milk yield in Holsteins and Jerseys. Journal of Dairy Science 86: 2967–2976.CrossRefGoogle ScholarPubMed
Danchin-Burge, C., Palhiére, I., Francois, D., Bibé, B., Leroy, G. & Verrier, E. 2009. Pedigree analysis of seven small French sheep populations and implications for the management of rare breeds. Journal of Animal Science 88: 505–516.Google Scholar
Dunner, S., Checa, M.L., Gutiérrez, J.P., Martín, J.P. & Canón, J. 1998. Genetic analysis and management in small populations: the Asturcon pony as an example. Genetics Selection Evolution 30: 397–405.CrossRefGoogle Scholar
Ercanbrack, S.K. & Knight, A.D. 1991. Effects of inbreeding on reproduction and wool production of Rambouillet, Targhee and Columbia sheep. Journal of Animal Science 69: 4734–4744.CrossRefGoogle Scholar
Falconer, D.S. & Mackay, T.F.C. 1996. Introduction to Quantitative Genetics. Longman, Harlow.Google Scholar
Ganesakale, D. & Rathnasabapathy, V. 1973. Sheep breeds of Tamil Nadu. Cheiron 2: 146–155.Google Scholar
Ghafouri-Kesbi, F. 2010. Analysis of genetic diversity in a close population of Zandi sheep using genealogical information. Journal of Genetics 89: 479–483.Google Scholar
Goyache, F., Gutiérrez, J.P., Fernández, I., Gómez, E., Álvarez, I., Díez, J. & Royo, L.J. 2003. Using pedigree information to monitor genetic variability of endangered populations: the Xalda sheep breed of Asturias as an example. Journal of Animal Breeding and Genetics 120: 95–103.Google Scholar
Gutiérrez, J.P. & Goyache, F. 2005. A note on ENDOG: a computer program for analysing pedigree information. Journal of Animal Breeding and Genetics 120: 357–360.Google Scholar
Gutiérrez, J.P., Altarriba, J., Díaz, C., Quintanilla, A.R., Cañón, J. & Piedrafita, J. 2003. Genetic analysis of eight Spanish beef cattle breeds. Genetics Selection Evolution 35: 43–64.CrossRefGoogle ScholarPubMed
Gutiérrez, J.P., Cervantes, I., Molina, A., Valera, M. & Goyache, F. 2008. Individual increase in inbreeding allows estimating realised effective sizes from pedigrees. Genetics Selection Evolution 40: 359–378.Google Scholar
Gutiérrez, J.P., Cervantes, I. & Goyache, F. 2009. Improving the estimation of realized effective population sizes in farm animals. Journal of Animal Breeding and Genetics 126: 327–332.CrossRefGoogle ScholarPubMed
Goyache, F., Fernandez, I., Espinosa, M.A., Payeras, L., Perez-Pardal, L., Gutierrez, J.P., Royo, L.J. & Alvarez, E.L. 2010. Demographic and genetic analysis of the Mallorquina sheep flockbook. Informacion Tecnica Economica Agraria 106: 3–14.Google Scholar
Haris, G., Sivaselvam, S.N., Karthickeyan, S.M.K. & Saravanan, G. 2007. Molecular characterisation of Nilagiri sheep (Ovis aries) of South India based on microsatellites. Asian-Australasian Journal of Animal Science 20: 633–637.Google Scholar
James, J.W. 1972. Computation of genetic contributions from pedigrees. Theory and Applied Genetics 42: 272–273.CrossRefGoogle ScholarPubMed
Lacy, R.C. 1989. Analysis of founder representation in pedigrees: founder equivalents and founder genome equivalents. Zoo Biology 8: 111–123.CrossRefGoogle Scholar
Lamberson, W.R., Thomas, D.L. & Rowe, K.E. 1982. The effect of inbreeding in a flock of Hampshire sheep. Journal of Animal Science 55: 780–786.CrossRefGoogle Scholar
Li, M.H., Strandén, I. & Kantanen, J. 2009. Genetic diversity and pedigree analysis of the Finnsheep breed. Journal of Animal Science 87: 1598–1605.CrossRefGoogle ScholarPubMed
Littlewood, R.W. 1936. Livestock of Southern India. Government of Madras, Madras, pp. 202–216.Google Scholar
Lutaaya, E., Misztal, I., Bertrand, J.K. & Mabry, J.W. 1999. Inbreeding in populations with incomplete pedigree. Journal of Animal Breeding and Genetics 116: 475–480.Google Scholar
Maiwashe, A.N. & Blackburn, H.D. 2010. Genetic diversity in and conservation strategy considerations for Navajo Churro sheep. Journal of Animal Science 82: 2900–2905.CrossRefGoogle Scholar
Mandal, A., Pant, K.P., Notter, D.R., Rout, P.K., Roy, R., Sinha, N.K. & Sharma, N. 2005. Studies on inbreeding and its effect on growth and fleece traits of Muzzaffarnagari sheep. Asian-Australasian Journal of Animal Science 18: 1363–1367.Google Scholar
Meuwissen, T.H.E. 1999. Operation of conservation schemes. In Oldenbroek, J.K. (ed) Genebanks and the Conservation of Farm Animal genetic Resources. DLO Institute for Animal Science and Health, Lelystad, The Netherlands, pp. 91–112.Google Scholar
Oravcova, M. & Krupa, E. 2011. Pedigree analysis of the former valachian sheep. Slovakian Journal of Animal Science 44: 6–12.Google Scholar
Oravcova, M. & Margetin, M. 2011. Preliminary assessment of trends in inbreeding and average relatedness of the Former Valachian sheep. Slovakian Journal of Animal Science 44: 90–96.Google Scholar
Prod'homme, P. & Lauvergne, J.J. 1993. The Merino Rambouillet flock in the National Sheep Fold in France. Small Ruminant Research 10: 303–315.CrossRefGoogle Scholar
Report, 2008. Sheep Breeding Research Station, Sandynallah. TANUVAS, Chennai (available at http://www.tanuvas.ac.in/SBRS.html)Google Scholar
Rieman, B.E. & Allendorf, F.W. 2001. Effective population size and genetic conservation criteria for Bull trout. North American Journal of Fisheries Management 21: 756–764.Google Scholar
Shortt, J. 1869. An account of the hill tribes of the Neilgherries. Transactions of the Ethnological Society of London 7: 230–290.Google Scholar
Vanwyk, J.B., Erasmus, G.J. & Konstantinov, K.V. 1992. Inbreeding in the Elsenburg Dormer sheep stud. South African Journal of Animal Science 23: 77–80.Google Scholar
Wright, S. 1923. Mendelian analysis of the pure breeds of livestock. I. The measurement of inbreeding and relationship. Journal of Heredity 14: 339–348.CrossRefGoogle Scholar
Wright, S. 1931. Evolution in Mendelian populations. Genetics 16: 97–159.CrossRefGoogle ScholarPubMed