Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-26T18:20:33.167Z Has data issue: false hasContentIssue false
  • English
  • Français

Post partum conception in lactating Awassi and East Friesian × Awassi dairy ewes

Published online by Cambridge University Press:  27 March 2009

M. Morag  and
E. Eyal
M. Morag
Affiliation:
Negev Institute for Arid Zone Research, Beer-Sheva, Israel
E. Eyal
Affiliation:
Volcani Institute of Agricultural Research, Rehovot, Israel
Get access Rights & Permissions [Opens in a new window]

Summary

Two attempts were made to increase the number of lamb crops in intensively managed dairy sheep flocks. Rams were introduced into the flocks for the first 100 days after lambing. The ewes were milked twice daily from parturition. In the first flock of 188 ewes, the lambs were weaned at birth. Half the ewes received a course of progesterone and PMS in the third week post partum. 49% of the treated ewes conceived at average of 49 days post partum, and 59% of the non-treated ewes at an average of 53 days post partum. The hormone treatment reduced milk yield by 17% in the ewes which conceived and by 26% in those which did not conceive. Milk yield was 7% lower in those ewes which conceived a second time. Yield in the subsequent lactation was very low. In the second flock, the lambs of 83 ewes were weaned 40 days after lambing. 89% of the sheep conceived at an average of 64 days after lambing. The pregnant ewes yielded 6% less milk than those ewes which did not conceive. Yield in the following lactation was satisfactory. The practical implications of the results in terms of the possibilities of future production in dairy flocks are discussed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 77 , Issue 1 , August 1971 , pp. 109 - 116
Copyright
Copyright © Cambridge University Press 1971

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amir, D. & Volcani, R. (1965). The sexual season of the Awassi fat-tailed ewe. J. agric. Sci., Camb. 64, 83–5.Google Scholar
Ayalon, N. (1968). (The use of hormones for oestrus synchronization in sheep.) Hanoked 48, 34–7 (Hebrew).Google Scholar
Copenhaver, J. S. & Carter, R. C. (1964). Maximizing ewe productivity by very early weaning and rebreeding. J. Anim. Sci. 23, 302.Google Scholar
Copenhaver, J. S. & Carter, B. C. (1966). Early weaning and multiple weaning. Prog. Rep. Va agric. Expl Stn, 1965–1966, 54–7.Google Scholar
Eyal, E. & Goot, H. (1968). Vital statistics and milk and lamb production of F 1 ewes (Awassi × East Friosian) under farm conditions. Volcani Institute of Agricultural Research Pamphlet no. 124, 1–24.Google Scholar
Finci, M. (1957). The improvement of the Awassi breed of sheep in Israel. Bull. Res. Coun. Israel 6B, 1–106.Google Scholar
Folman, Y., Volcani, R. & Eyal, E. (1966). Motheroffspring relationship in Awassi sheep. 1. The effect of different suckling regimes and time of weaning on the lactation curve and milk yield in dairy flocks. J. agric. Sci., Camb. 67, 359–68.CrossRefGoogle Scholar
Goot, H. (1965). Studies on the native Awassi sheep and its crosses with exotic East Friesian milk sheep. Ph.D. Thesis, Hebrew University, Jerusalem (Hebrew).Google Scholar
Gordon, I. (1963). The induction of pregnancy in the anoestrous ewe by hormonal therapy. V. Progesterone-pregnant mare's serum therapy on Clun forest maiden sheep and general conclusions. J. agric. Sci., Camb. 60, 77–85.CrossRefGoogle Scholar
Gordon, J. G. & Tribe, D. E. (1951). The self selection of diet by pregnant ewes. J. agric. Sci., Camb. 41, 187–90.Google Scholar
Hammond, J. (1957). Fertility and the production of fat lambs. Agric. Rev., Lond. 3, 23–7.Google Scholar
Hunter, G. L. (1968 a). Increasing the frequency of pregnancy in sheep. I. Some factors affecting rebreeding during the post partum period. Anim. Breed. Abstr. 36, 347–78.Google Scholar
Hunter, G. L. (1968 b). Increasing the frequency of pregnancy in sheep. II. Artificial control of breeding, and problems of conception and maintenance of pregnancy during the post partum period. Anim. Breed. Abstr. 36, 533–53.Google Scholar
Kali, J. & Amir, S. (1967). The relationship between the level of concentrate feeding and body weight, and conception rate, in Israeli-Friesian dairy cows. J. Dairy Sci. 50, 1011.Google Scholar
Mauléon, P. & Dauzier, L. (1965). Variations de durée de l'anoestrus de lactation chez les brebis de race Ile-de-France. Annls Biol. anim. Biochim. Bio-phys. 5, 131–43.Google Scholar
McDonald, P., Edwards, R. A. & Greenhalgh, J. F. D.. (1968). Animal Nutrition, pp. 188–9. Edinburgh and London: Oliver and Boyd.Google Scholar
Morag, M. (1966). Models of milk secretion in the ewe and the cow. Ph.D. Thesis, University of Reading.Google Scholar
Morag, M., Raz, A. & Eyal, E. (1970). Mother-offspring relationship in Awassi sheep. IV. The effect of weaning at birth, or after 15 weeks, on lactational performance in the dairy ewe. J. agric. Sd., Camb. 75, 183–7.Google Scholar
Reid, R. L. & Hinks, N. T. (1962). Feed requirements and voluntary food intake in late pregnancy. Aust. J. agric. Res. 13, 1092–111.Google Scholar
Smith, V. R. (1959). Physiology of Lactation, 5th ed. p. 84. Ames, Iowa: Iowa State University Press.Google Scholar
Smith, L. W. & Inskeep, E. K. (1970). Effect of progesterins on lactation in the ewe. J. Anim. Sci. 30, 957–9.Google Scholar
Solomonov, H. (1965). The effect of milking ewes during the breeding season on their performance. Zhivot. Nauk. 2, 217–23. (Bulgarian.)Google Scholar
Thibault, C. & Mauléon, P. (1964). Quelques problèmes neuro-endocriniens intéressants de la reproduction des mammifères domestiques. 5th Int. Congr. Anim. Reprod. A.I. Trento, 1964, vol. III, 427–70.Google Scholar
Wallace, L. R. (1948). The growth of lambs before and after birth in relation to the level of nutrition. J. agric. Sci., Camb. 38, 93–153.Google Scholar