Body Weight Change, Milk Production and Reproductive Parameters in Suckled vs. Non-suckled Awassi Ewes

  • Ishmais, M.A. Abu (Department of Animal production, Faculty of Agriculture, Jordan University of Science and Technology) ;
  • Kridli, R.T. (Department of Animal production, Faculty of Agriculture, Jordan University of Science and Technology) ;
  • Omer, S.A. (College of Veterinary Medicine and Animal Production, Sudan University of Science and Technology)
  • Received : 2003.10.10
  • Accepted : 2004.06.04
  • Published : 2004.09.01


The objective of this study was to identify the effect of early weaning on body weight change, milk production and the return to estrus in Awassi ewes. Twenty multiparous winter-lambing Awassi ewes were randomly assigned to either suckled (S, n=10) or non-suckled (NS, n=10) groups in a completely randomized design. Lambs in the NS group were removed from their dams on day 2 postpartum (PP). Animal body weights (BW) and body condition scores (BCS) were recorded at the beginning of the study and every 3 weeks thereafter until the end of the experiment. Milk production was estimated by machine milking at weekly intervals for 4 weeks beginning on d 11 PP. Blood samples were collected from each ewe every third day for 4 weeks beginning on day 15 PP. Initial body weight was similar for both treatments. By the end of the experiment, NS ewes gained an average of 1.8${\pm}$1.0 kg while S ewes lost an average of 7.0${\pm}$1.0 kg (p<0.001). Body condition scores followed a trend similar to that observed for BW and was greater (p<0.001) in the NS ewes. Significant correlation existed (p<0.01) between BW and BCS (r=0.77). The first milk production recording for both suckled and non-suckled was similar. Later recordings, however, showed that the S group had greater milk production (p<0.01) compared with the NS group. Lambs in the NS group were heavier (p<0.05) than those in the S group on d 10 PP. By the end of the study, lamb weights in the NS group were significantly lower (p<0.001) when compared with S group. The first rise in plasma progesterone ($P_{4}$) occurred earlier (p<0.05) in the NS than S ewes (day 27.0${\pm}$2.2 vs. 34.0${\pm}$2.2 postpartum, respectively). All of the NS ewes (10/10) and 60% (6/10) of the S ewes expressed estrus following ram introduction (p<0.05). Results of the current study indicate that non-suckled ewes gained more weight and displayed ovarian activity earlier than suckled ewes. Early lamb removal can be used to obtain biannual lambing in Awassi sheep.


  1. Carruthers, T. D. and H. D. Hafs. 1980. Suckling and four times daily milking: influence on ovulation, estrus and serum LH, glucocorticoids and prolactin in postpartum Holstein. J. Anim. Sci. 50:919-925.
  2. Schillo, K. K. 1992. Effects of dietary energy on control of luteinizing hormone secretion in cattle and sheep. J. Anim. Sci. 70:1271-1282.
  3. Schirar, A., Y. Cognie, F. Louault, N. Poulin, M. C. Levasseur and J. Martinet. 1990. Resumption of gonadotrophin release during the postpartum period in suckling ewes and non-suckling ewes. J. Reprod. Fertil. 88:593-604.
  4. Smart, D., I. Singh, R. F. Smith and H. Dobson. 1994. Opioids and suckling in relation to inhibition of estradiol-induced LH secretion in postpartum ewes. J. Reprod. Fert. 101:115-119.
  5. Mbayahaga, J., S. N. M. Mandiki, J. L. Bister and R. Paquay. 1998. Body weight, oestrus and ovarian activity in the local Burundian ewes and goats after parturition in the dry season. Anim. Reprod. Sci. 51(4):289-300.
  6. Yavas, Y. and J. S. Walton. 2000. Postpartum acyclicity in beef cows: A review. Theriogenology 54:25-55.
  7. Fray, M. D., G. E. Lamming and W. Haresign. 1995. Induction of ovulation in the acyclic postpartum ewe following continuous, low-dose subcutaneous infusion of GnRH. Theriogenology 43:1019-1030.
  8. Fadel, I., J. B. Owen, R. Kassem and H. Juha. 1989. A note on the milk composition of Awassi ewes. Anim. Prod. 48:606-610.
  9. Wallace, J. M., J. J., Robinson and R. P. Aitken. 1989. Does inadequate luteal function limit the establishment of pregnancy in early postpartum ewe? J. Reprod. Fertil. 85:229-240.
  10. Edgerton, L. A. 1980. Effect of lactation upon the postpartum interval. J. Anim. Sci. 51(Suppl. II):40-52.
  11. Mitchell, L. M., M. E. King, F. E. Gebbie, M. J. Ranilla and J. J. Robinson. 1998. Resumption of estrus and ovarian cyclicity during the postpartum period in autumn-lambing ewes is not influenced by age or dietary protein content. Animal Science 67:65-72.
  12. Schirar, A., Y. Cognie, F. Louault, N. Poulin, M. C. Levasseur and J. Martinet. 1989. Resumption of estrus behavior and cyclic ovarian activity in suckling ewes and non-suckling ewes. J. Reprod. Fertil. 87:789-794.
  13. Hamadeh, S. K., E. K. Barbour, M. Abi-Said and K. Daadaa. 1996. Reproductive performance of postpartum Awassi ewes under different lambing regimes. Small Rum. Res. 19(2):149-154.
  14. Williams, G. L. 1990. Suckling as a regulator of postpartum rebreeding in cattle: A review. J. Anim. Sci. 68:831-852.
  15. Boland, M. P., P. Lonergan and D. O’Callaghan. 2001. Effect of nutrition on endocrine parameters, ovarian physiology, and oocyte and embryo development. Theriogenology 55:1323-1340.
  16. Harb, M. 1994. The use of progesterone sponges and PMSG in Awassi sheep reproduction. Dirasat. 21:149-161.
  17. National Research Council. 1985. Nutrient requirement of sheep. $6^{th}$ Rev. Edition. National Academy of Sciences. Washington, DC.
  18. Rutter, L. M. and R. D. Randel. 1984. Postpartum nutrient intake and body condition: Effect on pituitary function and onset of estrus in beef cattle. J. Anim. Sci. 58: 265-274.
  19. Mandiki, S. N. M., J. L. Bister and R. Paquay. 1990. Effects of suckling mode on endocrine control of reproductive activity resumption in Texel ewes lambing in July or November. Theriogenology 33:397-413.
  20. Tasende, C., A. Meikle, E. Rubianes and E. G. Garofalo. 1996. Restoration of estrogen and progesterone uterine receptors during the ovine postpartum period. Theriogenology 45:1545-1551.
  21. Scaramuzzi, R. J., Y. Cognie and J. A. Downing. 1996. The ovarian secretion of androstenedione and estradiol during late pregnancy and the early postpartum period in sheep with an autotransplanted ovary. Reprod. Nutr. Dev. 36:531-543.
  22. Kridli, R. T., S. G. Haddad and M. M. Muwalla. 2001. The effect of feeding ruminally undegradable protein on postpartum reproduction of Awassi ewes. Asian-Aust. J. Anim. Sci. 14:1125-1128.
  23. Rhind, S. M., S. McMillen, W. A. C. Mckelvey, F. F. Rodriguez-Herrejon and A. S. McNeilly. 1989. Effect of the body condition of ewes on the secretion of LH and FSH and the pituitary response to gonadotropin-releasing hormone. J. Endocrinol. 120:497-502.
  24. SAS Institue Inc. 1989. SAS/STAT User’s Guide: Version 6. 4th edn. SAS Institute Inc. Cary, North Carolina.
  25. Epstein, H. 1982. Awassi sheep. World Anim. Rev. 44:9-18.

Cited by

  1. Alfalfa hay improves nursing performance of Awassi ewes and performance of growing lambs when used as a source of forage compared with wheat straw pp.1573-7438, 2018,