Effects of Inbreeding on Lamb Survival in a Flock of Muzaffarnagari Sheep

  • Mandal, Ajoy (Genetics and Breeding Division, Central Institute for Research on Goats, Makhdoom) ;
  • Pant, K.P. (Central Institute for Research on Goats, Makhdoom) ;
  • Rout, P.K. (Genetics and Breeding Division, Central Institute for Research on Goats, Makhdoom) ;
  • Roy, R. (Genetics and Breeding Division, Central Institute for Research on Goats, Makhdoom)
  • Received : 2003.03.04
  • Accepted : 2004.01.15
  • Published : 2004.05.01


A pedigree file of 4,628 records of Muzaffarnagari sheep, maintained at Central Institute for Research on Goats (CIRG), Makhdoom, was used to calculate the inbreeding coefficient of the flock. The flock had been closed for about 25 years (1978 to 2002). The investigation was aimed to study the effects of inbreeding on survivability of lambs. The cumulative survivability of lambs i.e., lambs survived up to 3, 7 and 15 days, 1, 2, 3, 6, 9 and 12 months after birth was considered for the study. The average level of inbreeding of lambs was 1.60%, ranging from 0 to 26.4%. The average inbreeding coefficient of dam over the periods was 1.00% and it ranged from 0 to 25.0%. Significant (p<0.05) adverse effect of lamb's inbreeding was observed on survivability of lambs at all ages except up to 3 and 7 days after birth. On an average, 1% increase in individual inbreeding coefficient should reduce the 0.31, 0.34, 0.32, 0.31, 0.33, 0.44 and 0.49 percent lamb survival up to the age of 15 day and 1, 2, 3, 6, 9 and 12 months, respectively. Ewes inbreeding had non-significant effects on lamb survival at all ages.


Supported by : Sheep Unit of Institute


  1. Lamberson, W. R. and D. L. Thomas. 1984. Effects of inbreeding in sheep: a review. Anim. Breed. Abstr. 52:287-297.
  2. Wiener, G., G. J. Lee and J. A. Woolliams. 1992. Effects of rapid inbreeding and of crossing inbred lines on the body weight growth of sheep. Anim. Prod. 55: 89-99.
  3. Clarke, J. N. 1982. Mating plans and their effects in sheep improvement. In: Sheep Production, Vol. 1. Breeding and reproduction. Wellington, New Zealand, New Zealand Institute of Agricultural Science and Ray Richard Publisher.
  4. Ercanbrack, S. K. and A. D. Knight. 1991. Effects of inbreeding on reproduction and wool production of Rambouillet, Targhee, and Columbia ewes. J. Anim. Sci. 69:4734-4744.
  5. Galal, E. S. E., E. A. Afifi, S. El-Kimaray, I. A. Ahmad and A. F. Shawar. 1981. Lamb survival as affected by inbreeding and cross-breeding. J. Agric. Sci. (Camb.) 96 (1):1-5.
  6. Van Wyk, J. B., G. J. Erasmus and K. V. Konstatinov. 1993. Inbreeding in the Elsenburg Dormer sheep stud. S. Afr. Anim. Sci. 23(3/4):77-80.
  7. Lamberson, W. R., D. L. Thomas and K. E. Rowe. 1982. The effect of inbreeding in a flock of Hampshire sheep. J. Anim. Sci. 55 (4):780-786.
  8. Lax, J. and G. H. Brown. 1967. The effects of inbreeding, maternal handicap and range in age on 10 fleece and body characteristics in Merino rams and ewes. Aust. J. Agric. Res. 18:689-706.
  9. Mandal, A., L. B. Singh and P. K. Rout. 2000. The Muzaffarnagari sheep, a mutton breed in India. Animal Genetic Resources Information, Rome, Food and Agricultural Organization. 28:19-25.
  10. Doney, J. M. 1957. Effects of inbreeding on four families of Peppin Merinos. Aust. J. Agric. Res. 8:299-311.
  11. Afifi, E. A., E. S. E. Galal and I. S. El-Kimary. 1984. Lamb livability in two closed flocks of local Rahmani and Barki sheep. J. Anim. Breed. Gen. 101:312.
  12. Harvey W. R. 1990. User's Guide for LSMLMW MIXMDL, PC-2 Version, Columbus, Ohio, USA.
  13. Bhat, P. N., B. U. Khan, S. K. Koul and S. K. Bhadula. 1978. Breed characteristics of Muzaffarnagri sheep. Indian J. Anim. Sci. 48(7):506-510.
  14. Wiener, G., Carol, Woolliams and N. S. M. Macleod. 1983. The effect of breed, breeding system and other factors on lamb mortality. J. Agric. Sci. (Camb.) 100:539-551.

Cited by

  1. Life history correlates of inbreeding depression in mandrills (Mandrillus sphinx) vol.15, pp.1, 2005,
  2. Inbreeding depression in non-human primates: a historical review of methods used and empirical data vol.69, pp.12, 2007,
  3. Preliminary study of the genetic diversity of eastern Assamese macaques (Macaca assamensis assamensis) in Thailand based on mitochondrial DNA and microsatellite markers vol.55, pp.2, 2014,