Shearing Pregnant Ewes to Improve Lamb Birth Weight Increases Milk Yield of Ewes and Lamb Weaning Weight

  • Cam, M.A. (Ondokuz Mayis University, Faculty of Agriculture, Department of Animal Science, Kurupelit) ;
  • Kuran, M. (Ondokuz Mayis University, Faculty of Agriculture, Department of Animal Science, Kurupelit)
  • Received : 2003.12.19
  • Accepted : 2004.05.21
  • Published : 2004.12.01


Milk yield, lamb birth weight and weaning weight responses to shearing during winter in sheep were investigated. A total of 46 Karayaka ewes were allocated into two treatment groups. Pregnant ewes in one group were shorn on day 100 of gestation (Shorn, n=24) and the remaining ewes were left unshorn to serve as controls (Unshorn, n=22). The ewes were maintained on pasture during the day and housed in the evenings. Lamb birth weight, weaning weight and ewes'' daily milk yield in fifteen dayintervals until weaning (75 days) were recorded. Shearing ewes on day 100 of pregnancy increased gestation length (p<0.01) compared to unshorn ewes (147.8${\pm}$0.45 vs. 145.9${\pm}$0.42 days). Birth weights of lambs from shorn ewes on day 100 of their pregnancy were higher (p<0.01) than those from unshorn ewes (3.7${\pm}$0.11 vs. 3.2${\pm}$0.07 kg). Shearing pregnant ewes increased (p<0.05) the lamb weaning weight at day 75 post-lambing (23.6${\pm}$1.10 vs. 19.5${\pm}$0.91). It also increased milk yield (p<0.05). Milk yields on day 75 of lactation were 302${\pm}$33 and 425${\pm}$25 g per day for unshorn and shorn ewes on day 100 of pregnancy, respectively. Lamb survival at weaning was higher (p<0.05) in lambs from shorn ewes compared to those from unshorn ewes. In conclusion, shearing pregnant ewes in winter months enhanced milk yield, lamb birth weight, lamb weaning weight and lamb survival. It is suggested that increasing both lamb birth weight and subsequent milk yield of dams by shearing ewes on day 100 of pregnancy during winter may improve postnatal lamb viability.


Supported by : ndokuz Mayis University, Faculty of Agriculture Research Fund


  1. Black, H. J. and D. M. B. Chestnutt. 1990. Influence of shearing regime and grass silage quality on the performance of pregnant ewes. Anim. Prod. 51:573-582.
  2. Chaturvedi, O. H., R. Bhatta, A. Santra, A. S. Mishra and J. S. Mann. 2003. Effect of supplementary feeding of concentrate on nutrient utilization and production performance of ewes grazing on community rangeland during late gestation and early lactation. Asian-Aust. J. Anim. Sci. 16:983-987.
  3. Clarke, L., M. J. Bryant, M. A. Lomax and M. E. Symonds. 1997. Maternal manipulation of brown adipose tissue and liver development in the ovine fetus during late gestation. Br. J. Nutr. 77:871-783.
  4. Dabiri, N., C. W. Holmes, S. N. McCutcheon, W. J. Parker and S. T. Morris. 1995. Resistance to cold stress in sheep shorn by cover comb or standard comb. Anim. Sci. 60:451-456.
  5. Knight, C. H. 2000. The importance of cell division in udder development and lactation. Livest. Prod. Sci. 66:169-176.
  6. McFadin, E. L., C. D. Morrison, P. R. Buff, N. C. Whitley and D. H. Keisler. 2002. Leptin concentrations in periparturient ewes and their subsequent offspring. J. Anim. Sci. 80:783-743.
  7. Perry, V. E. A., S. T. Norman, R. C. W. Daniel, P. C. Owens, P. Grant and V. J. Doogan. 2002. Insulin-like growth factor levels during pregnancy in the cow are affected by protein supplementation in the maternal diet. Anim. Reprod. Sci. 72:1-10.
  8. Sejrsen, K., S. Purup, M. Vestergaard, M. S. Weber and C. H. Knight. 1999. Growth hormone and mammary development. Domest. Anim. Endoc. 17:117-129.
  9. Swanson, E. W. and J. I. Poffenberger. 1978. Mammary development of dairy heifers during their first gestation. J. Dairy Sci. 62:702-714.
  10. Yuen, B. S., I. C. McMillen, M. E. Symonds and P. C. Owens. 1999. Abundance of leptin mRNA in fetal adipose tissue is related to fetal body weight. J. Endocrinol. 163:R11-14.
  11. Morris, S. T. and S. N. McCutcheon. 1997. Selective enhancement of growth in twin fetuses by shearing ewes in early gestation. Anim. Sci. 65:105-110.
  12. Thompson, G. E., J. M. Bassett, D. E. Samson and J. Slee. 1982. The effects of cold exposure of pregnant sheep on foetal plasma nutrients, hormones and birth weight. Br. J. Nutr. 48:59-64.
  13. Rastogi, A., N. Dutta and K. Sharma. 2003. Effect of strategic feed supplementation during gestation on intake, blood-biochemical profile and reproductive performance of goats. Asian-Aust. J. Anim. Sci. 16:1725-1731.
  14. Rattray, P. V., W. N. Garrett, N. E. East and N. Hinman. 1974. Growth, development and composition of the ovine conceptus and mammary gland during pregnancy. J. Anim. Sci. 38:613-626.
  15. Revell, D. K., S. F. Main, B. H. Breier, Y. H. Cottam, M. Hennies and S. N. McCutcheon. 2000. Metabolic responses to midpregnancy shearing that are associated with a selective increase in the birth weight of twin lambs. Domest. Anim. Endocrinol. 18:409-422.
  16. Waldes, P. D., W. Ruan, M. Feldman and D. L. Kleinberg. 1998. Evidence that the mammary fat pad mediates the action of growth hormone in mammary gland development. Endocrinol. 139:659-662.
  17. Harding, J. E., L. Liu, P. C. Evans and P. D. Gluckman. 1994. Insulin-like growth factor 1 alters feto-placental protein and carbohydrate metabolism in fetal sheep. Endocrinol. 134:1509-1514.
  18. Jopson, N. B., G. H. Davis, P. A. Farquhar and W. E. Bain. 2002. Effects of mid-pregnancy nutrition and shearing on ewe body reserves and foetal growth. Proc. NZ. Soc. Anim. Prod. 62:49-52.
  19. Bonnet, M., I. Gourdou, C. Leroux, Y. Chilliard and J. Djiane. 2002. Leptin expression in the ovine mammary gland: Putative sequential involvement of adipose, epithelial, and myoepithelial cells during pregnancy and lactation. J. Anim. Sci. 80:723-728.
  20. Kenyon, P. R., S. T. Morris, D. K. Revell and S. N. McCutcheon. 2002b. Nutrition during mid to late pregnancy does not affect the birth weight response to mid pregnancy shearing. Austr. J. Agric. Res. 53:13-20.
  21. Forsyth, I. A. 1996. The insulin-like growth factor and epidermal growth factor families in mammary cell growth in ruminants: action and interactions with hormones. J. Dairy Sci. 79:1085-1096.
  22. Kenyon, P. R., S. T. Morris, D. K. Revell and S. N. McCutcheon. 2002a. Maternal constraint and the birth weight response to mid-pregnancy shearing. Austr. J. Agric. Res. 53:511-517.
  23. Chilliard, Y., M. Bonnet, C. Delevaud, Y. Faulconnier, C. Leroux, J. Djiane and F. Bocquier. 2001. Leptin in ruminants. Gene expression in adipose tissue and mammary gland, and regulation of plasma concentration. Domest. Anim. Endocrinol. 21:271-295.
  24. Chaiyabutr, N., S. Komolvanich, S. Thammacharoen and S. Chanpongsang1. 2004. The plasma level of insulin-like growth factor-I (IGF-I) in relation to mammary circulation and milk yield in two different types of crossbred Holstein cattle. Asian-Aust. J. Anim. Sci. 17:343-348.
  25. Mead, R. and R. N. Curnow. 1990. Statistical Methods in Agriculture and Experimental Biology. Chapman and Hall, London.
  26. Symonds, M. E., M. J. Bryant, L. Clarke, C. J. Darby and M. A. Lomax. 1992. Effect of maternal cold exposure on brown adipose tissue and thermogenesis in the neonatal lamb. J. Physiol. (London) 455:487-502.
  27. Morris, S. T., S. N. McCutcheon and D. K. Revell. 2000. Birth weight responses to shearing ewes in early to mid gestation. Anim. Sci. 70:363-369.
  28. Revell, D. K., S. T. Morris, Y. H. Cottam, J. E. Hanna, D. G. Thomas, S. Brown and S. N. McCutcheon. 2002. Shearing ewes at mid-pregnancy is associated with changes in fetal growth and development. Austr. J. Agric. Res. 53:697-705.
  29. Ocak, N., M. A. Cam and M. Kuran. 2004. The effect of high dietary protein levels during late gestation on clolstrum yield and lamb survival rate in singleton-bearing ewes. Small Rumin. Res. (in press).
  30. Symonds, M. E., M. J. Bryant and M. A. Lomax. 1986. The effect of shearing on the energy metabolism of the pregnant ewe. Br. J. Nutr. 56:635-643.
  31. Assan, N., S. Makuza, F. Mhlanga and O. Mabuku. 2002. Genetic evaluation and selection response of birth weight and weaning weight in indigenous Sabi sheep. Asian-Aust. J. Anim. Sci.15:1690-1694.
  32. Knight, C. H. and C. J. Wilde. 1993. Mammary cell changes during pregnancy and lactation. Livest. Prod. Sci. 53:3-19.
  33. SPSS. 1998. SPSS Inc. Headquarters, (Release 9.0) 233 S. Wacker Drive, 11th floor Chicago, Illinois 60606.
  34. Laud, K., I. Gourdou, L. Belair, D. H. Keisler and J. Djian. 1999. Detection and regulation of leptin receptor mRNA in ovine mammary epithelial cells during pregnancy and lactation. FEBS Letters 463:194-198.
  35. Vipond, J. E., M. E. King and D. M. Inglis. 1987. The effect of winter shearing of housed pregnant ewes on food intake and animal performance. Anim. Prod. 45:211-221.

Cited by

  1. Mid-pregnancy shearing can increase birthweight and survival to weaning of multiple-born lambs under commercial conditions vol.46, pp.7, 2006,
  2. Shearing male lambs in the cold season improves the carcass yield without affecting fattening performance vol.78, pp.3, 2007,
  3. Mid-pregnancy shearing of autumn-lambing ewes in New Zealand vol.48, pp.7, 2008,
  4. Birth weight effect in twin‐born lambs from mid‐pregnancy shearing is associated with changes in maternal IGF‐I concentration vol.52, pp.3, 2009,
  6. Time of shearing the ewe not only affects lamb live weight and survival at birth and weaning, but also ewe wool production and quality pp.1175-8775, 2017,
  7. Shearing ewes in the first third of gestation improves offspring performance vol.58, pp.10, 2018,
  8. Heat dissipation rate constrains reproductive investment in a wild bird vol.33, pp.2, 2019,