Indian Journal of Animal Research

  • Chief EditorK.M.L. Pathak

  • Print ISSN 0367-6722

  • Online ISSN 0976-0555

  • NAAS Rating 6.50

  • SJR 0.263

  • Impact Factor 0.5 (2023)

Frequency :
Monthly (January, February, March, April, May, June, July, August, September, October, November and December)
Indexing Services :
Science Citation Index Expanded, BIOSIS Preview, ISI Citation Index, Biological Abstracts, Scopus, AGRICOLA, Google Scholar, CrossRef, CAB Abstracting Journals, Chemical Abstracts, Indian Science Abstracts, EBSCO Indexing Services, Index Copernicus
Indian Journal of Animal Research, volume 54 issue 11 (november 2020) : 1324-1331

Genetic Variability of Bharat Merino Sheep Derived from Pedigree Information

P.K. Mallick, I. Chauhan, S.M.K. Thirumaran, R. Pourouchttamane, Arun Kumar
1Animal Genetics and Breeding Division, ICAR-Central Sheep and Wool Research Institute, Avikanagar-304 501, Jaipur, Rajasthan, India. 
Cite article:- Mallick P.K., Chauhan I., Thirumaran S.M.K., Pourouchttamane R., Kumar Arun (2020). Genetic Variability of Bharat Merino Sheep Derived from Pedigree Information. Indian Journal of Animal Research. 54(11): 1324-1331. doi: 10.18805/ijar.B-3847.
Background: The genetic variability in a population is the raw material for selection, because the estimation of genetic parameters depends on the variability present within the population. The pedigree analysis is a method to assess population genetic variability. An increase in the level of inbreeding disturbs the production performance of the animals. Hence, it is essential to assess the effect of inbreeding on production performance of the animals at regular intervals. The present study was conducted on data of Bharat Merino (BM) sheep with twin objectives of evaluating the population structure by pedigree analysis and possible effect of inbreeding on lamb growth and heritability estimates. 
Methods: The study was conducted on data consisting of a total of 9688 pedigree records of BM sheep born from 1975 to 2018 (43 years), out of which 9050 formed population reference (with both the parents known). ENDOG ver 4.8 program was used to generate different measures of genetic diversity. General Linear Model of SPSS 25.0 was used to ascertain the effect of inbreeding (Fi) or change in inbreeding (ÄFi) on the lamb live weights. Using animal model with software WOMBAT, single trait linear mixed model analyses were performed. The heritability estimates and breeding values were obtained by including or excluding the inbreeding coefficient in the model to observe how the estimates of heritability varied with inclusion or exclusion of the inbreeding coefficient. 
Result: Effective number of founders (fe) was 56, constituting 11.39% founders in the population reference, while the effective number of ancestors (fa) was 43.The genetic contribution of the 15 most influent ancestors explained 50% of the genetic variability in the dataset. The ratio fe/fa, representing the effect of population bottleneck, was 1.302. The average inbreeding coefficients for the whole pedigree was 2.36%, while it was 3.84% for inbred animals. It was found that the inbreeding coefficient (Fi) increased with the addition of each generation to the pedigree. The average relatedness coefficient was 4.53% between members of the population.The effect of individual inbreeding (Fi) or the change in inbreeding (DFi) was not significant on the lamb live weights, except the effect of individual inbreeding (Fi) on three-month body weight and average daily gain (0-3month) and of change in inbreeding (DFi) on three-month body weight. From the analysis of the pedigree data of Bharat Merino sheep, it was found that the most of the measures of genetic diversity were within acceptable limits and the pedigree data was reasonably well maintained. When inbreeding was accounted for in the model, there were reductions in h2 estimates as well as the estimates of breeding values for both 3WT and ADG1 and consequently there were changes in ranking of animals for both 3WT and ADG1. 
  1. Barczak, E., Wolc, A., Wojtowski, J., Slosarz, P. and Szwaczkowski, T. (2009). Inbreeding and inbreeding depression on body weight in sheep. J. Anim. Feed Sci. 18: 42-50.
  2. Barros, E.A., Brasi, A., Tejero, J.P., Delgado-Bermejo, J.V. and Ribeiro, M.N. (2017). Population structure and genetic variability of the Segureña sheep breed through pedigree analysis and inbreeding effects on growth traits. Small Ruminant Research.149: 128-133.
  3. Boichard, D., Maignel, L., Verriel, E. (1997). The value of using probabilities of gene origin to measure genetic variability in a population. Genet. Sel. Evol. 29: 5-23.
  4. Danchin-Burge, C., Palhiere, I., Francosis, D., Bibe, B., Leroy, G. and Verrier, E. (2010). Pedigree analysis of seven small French sheep populations and implications for the management of rare breeds. J. Anim. Sci. 88: 505-516.
  5. Ghafouri-Kesbi, F. (2010). Analysis of genetic diversity in a close population of Zandi sheep using genealogical information. J. Genet. 89: 479-483.
  6. Ghafouri-Kesbi, F. (2012). Using pedigree information to study genetic diversity and re-evaluating a selection program in an experimental flock of Afshari sheep. Arch. Fuer Tierz. 55: 375-384.
  7. Gonzalez-Recio, O., Lopez de Maturana, E. and Gutiérrez, J.P.J. (2007). Inbreeding depression on female fertility and calving ease in Spanish dairy cattle. J. Dairy Sci. 90: 5744-5752.
  8. Gowane, G.R., Chopra, A., Misra, S.S. and Prince L.L.L. (2014). Genetic diversity of a nucleus flock of Malpura sheep through pedigree analyses. Small Rumin Res. 120: 35-41.
  9. Gowane, G.R., Chopra, A., Prince, L.L.L. and Arora, A.L. (2010a). Effect of inbreeding on lamb growth traits in a closed flock of Bharat Merino sheep. Indian Vet. J. 87: 42-44. 
  10. Gowane, G.R., Prakash, V., Chopra, A and Prince, L.L.L. (2013). Population structure and effect of inbreeding on lamb growth in Bharat Merino sheep. Small Rumin Res. 114: 72-79.
  11. Gowane,G.R., Prince, L.L.L., Ved Prakash, Sharma, R.C. and Kumar, A. (2016). Decline in Additive Genetic Variance for Live Weight and Greasy Fleece Weight in Bharat Merino Sheep. Agricultural Research. 5: 316-323.
  12. Gutierrez, J.P. and Goyache, F. (2005). A note on ENDOG: a computer program for analyzing pedigree information. J. Anim. Breed. Genet. 122: 172–176.
  13. Gutierrez, J.P., Cervantes, I. and Goyache, F. (2009). Improving the estimation of realized effective population sizes in farm animals. J. Anim. Breed. Genet.126: 327–332.
  14. Lacy, R.C. (1989). Analysis of founder representation in pedigrees: founder equivalents and founder genome equivalents. Zoo Biol. 8: 111–123.
  15. Mallick, P.K., Thirumaran, S.M.K., Pourouchottamane, R., Rajapandi, S. Venkatramanan, R., Nagarajan, G., Murali. G. and Rajendiran, A.S. (2016). Genetic trend for growth and wool performance in a closed flock of Bharat Merino sheep at sub temperate region of Kodai hills, Tamil Nadu. Veterinary World. 9: 276-280. 
  16. Mandal, A., Pant, P.K., Rout, P.K., Singh, S.A. and Roy, R. (2002). Influence of inbreeding on growth traits of Muzaffarnagari sheep. Indian J Ani Sci. 72: 988-990.
  17. Meuwissen, T.H.E. and Luo, Z. (1992). Computing inbreeding coefficients in large populations. Genet. Sele. Evol. 24: 305-313.
  18. Meyer, K. (2007). WOMBAT-a tool for mixed model analyses in quantitative genetics by restricted maximum likelihood (REML). J. Zhejiang Univ. Sci. 11: 815-821.
  19. Mokthari, M.S., Shahrbabak, M.M., Esmailzaduh, A.K., Shahrbabak, M.H. and Gutierez, J. P (2014). Pedigree analysis of Iran-Black sheep inbreeding effects on growth and reproduction traits. Small Rumin. Res. 116: 14-20.
  20. Oravcova, M. and Krupa, E. (2011). Pedigree analysis of the former Valachian sheep. Anim. Sci. 44: 6-12.
  21. Pedrosa, V.B., Santana Jr., Oliveira, P.S., Eler, J.P. and Ferraz, J.B.S. (2010). Population structure and inbreeding effects on growth traits of Santa lnes sheep in Brazil. Small Rumin. Res. 93: 135-139.
  22. Prakash, V., Prince, L.L.L., Gowane, G.R. and Arora, A.L. (2012). The estimation of (co) variance components and genetic parameters for growth traits and Kleiber ratios in Malpura sheep of India. Small Rumin. Res.108: 54-58.
  23. Prince, L.L.L., Kumar, S., Mishra, A.K. and Arora, A.L. (2008). Status of inbreeding in a closed flock of Avikalin Sheep. Indian Vet. J. 85: 1054-1056.
  24. Tahmoorespour, M., Sheikhloo, M., (2011). Pedigree analysis of the closed nucleus of Iranian Baluchisheep. Small Rumin. Res. 99: 1-6.
  25. Valera, M., Molina, A., Gutierrez, J.P., Gomez, J., Goyache, F. (2005). Pedigree analysis in the Andalusian horse: population structure, genetic variability and influence of the Carthusian strain. Livest. Prod. Sci. 95: 57-66.
  26. Vatankhah, M., Anil, S. and Abdollahi-Arpanahi. R. (2019). Population structure of Lori-Bakhtiari sheep in Iran by pedigree analysis. Small Rumin. Res. 174: 148-155.
  27. Venkataramanan, R., Subramani, A., Sivaselvam, S.N. and Sivkumar, T. (2013). Pedigree analysis of the Nilagiri sheep of South India. Animal Gen. Res. 53: 11-18. 

Editorial Board

View all (0)