Skip to main content Accessibility help

The seasonality of reproductive performance of Merino sheep in Britain

  • W. M. Tempest (a1) and T. G. Boaz (a1)


A study has been carried out to determine the length of the breeding season and the feasibility of lambing twice a year in Merino sheep in Britain.

Six groups of 18 ewes were exposed to rams at monthly intervals, and twice per year, from April 1969 to June 1970. A well-defined breeding season, from August to January, was found, and its shortness, linked with the inability of the ewes to conceive immediately post partum, prevented lambing twice in the year.



Hide All
Averill, R. L. W. 1955. Fertility of the ewe. In Studies on Fertility (ed. Harrison, R. G.), Vol. 7, Ch. 14, pp. 139148. Blackwell Scientific, Oxford.
Barrett, J. F., Reardon, T. F. and Lambourne, L. J. 1962. Seasonal variation in reproductive performance of Merino ewes in northern New South Wales. Aust. J. exp. Agric. Anim. Husb. 2: 6974.
Forbes, J. M. 1968. Partial synchronisation of oestrus in ewes resulting from the introduction of rams. Vie Int. Cong. Anim. Reprod. Artif. Insem., Paris, 1968, Vol. 11, pp. 14351438.
Hafez, E. S. E. 1952. Studies on the breeding season and reproduction of the ewe. J. agric. Sci., Comb. 42: 189231.
Hammond, J. 1957. Fertility and the production of fat lamb. Agric. Rev., Lond. 3: 2327.
Hammond, J. 1960. In Farm Animals, Their Growth, Breeding and Inheritance, 3rd ed., p. 95. Edward Arnold, London.
Hunter, G. L. 1962. Observations on oestrus in Merinos. Proc. S. Afr. Soc. Anim. Prod. 1:6769.
Hunter, G. L. 1968. Increasing the frequency of pregnancy in sheep. I. Some factors affecting rebreeding during the post-partum period. Anim. Breed. Abstr. 36: 347378.
Kelley, R. B. 1937. Studies in fertility of sheep. Bull. Coun. sci. industr. Res. Aust., No. 112.
Kelley, R. B. 1946. Studies on the breeding performance of ewes. Bull. Coun. sci. industr. Res. Aust., No. 205.
Kelley, R. B. and Shaw, H. E. B. 1943. Fertility in sheep. An experimental study of periodicity of oestrus and non-breeding seasons in Australia. Bull. Coun. sci. industr. Res. Aust., No. 166.
Kirillov, V. 1944. [The organisation of two lamb crops in a year.] Sovhoz. Proizvod., 12: 3436.
Large, R. V. 1970. The biological efficiency of meat production in sheep. Anim. Prod. 12: 393401.
Newton, J. E. and Betts, J. E. 1966. Factors affecting litter size in the Scots Halfbred ewe. I. Treatment with PMS and progesterone. J. Reprod. Fert. 12: 165175.
Radford, H. M. and Watson, R. H. 1957. Influence of rams on ovarian activity and oestrus in Merino ewes in the spring and early summer. Aust. J. agric. Res. 8: 460470.
Riches, J. H. and Watson, R. H. 1954. The influence of the introduction of rams on the incidence of oestrus in Merino ewes. Aust. J. agric. Res. 5: 141147.
Schinckel, P. G. 1954. The effect of the presence of the ram on the ovarian activity of the ewe. Aust. J. agric. Res. 5: 465469.
Smith, I. D. 1962. Nutrition and oestrus. Aust. vet. J. 38: 338340.
Spedding, C. R. W. 1965. In Sheep Production and Grazing Management. 1st ed., p. 348. Bailliere, Tindall and Cox, London.
Spedding, C. R. W., Betts, J. E., Large, R. V., Wilson, I. A. N. and Penning, P. D. 1967. Productivity and intensive sheep stocking over afive-yearperiod. J. agric. Sci., Camb. 69: 4769.
Tempest, W. M. and Boaz, T. G. 1970. The impact of hormone treatment on the reproductive and lamb-rearing performance of Scottish Halfbred ewes. Anim. Prod. 12: 358 (Abstr.).
Underwood, E. J., Shier, F. L. and Davenport, N. 1944. Sheep husbandry in Western Australia. V. The breeding season of Merino, Crossbred and British breed ewes in the agricultural districts. J. Dept. Agric. West. Aust. 21: 135143.
Watson, R. H. 1962. Seasonal variation in occurrence of oestrus in Merino ewes in Southern Victoria. Aust. vet. J. 38: 310323.

The seasonality of reproductive performance of Merino sheep in Britain

  • W. M. Tempest (a1) and T. G. Boaz (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed