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Oestrous activity of Suffolk, Mutton Merino and their crosses with subtropical Ossimi sheep

  • A. M. Aboul-Naga (a1), M. B. Aboul-Ela (a1) and F. Hassan (a1)

Summary

Two trials were conducted to study the seasonal variation in oestrous activity over the year in Suffolk (S) or mutton Merino (M) temperate breeds, and their crosses with the local Ossimi (O) sheep under the prevailing subtropical conditions. In the first trial, groups of S, 75% S, 50% S, and O were used and the second trial involved groups of M, ¾M, ½M, ½M and O. The incidence of oestrus was measured by teasing with vasectomized rams. Suffolk ewes had a restricted period of oestrous activity (August–January) whereas M had a longer breeding season (August–March) with high incidence of long and double cycles. Local O showed irregular oestrous activity almost around the year, with particular decline in April. In both trials, all crosses had better oestrous activity than the pure parents, with the 50% S and the ½M having the best performance in the two trials, respectively. The period from September to February seemed to be the period of normal cycling activity in all breed groups, whereas the period from March to May was associated with marked breed-group variation in oestrous activity. Normal cycle length of the S was significantly (P < 0·01) shorter than the local O (16·0 v.17·7 days) and was more consistent than other breed groups. In the two trials, normal cycle length of the cross-breds was ranked between the two purebred parents.

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Aboul-Naga, A. M. (1975). Reproductive performance of Merino, sub-tropical Egyptian sheep and their crosses. Journal of Agricultural Science, Cambridge 84, 383386.
Aboul-Naga, A. M. (1978). Using Suffolk sheep for improving lamb production from sub-tropical Egyptian sheep. 1. Reproductive performance. Journal of Agricultural Science, Cambridge 90, 125130.
Aboul-Naga, A. M. & Aboul-Ela, M. B. (1984). Oestrous activity of Egyptian fat-tailed Ossimi ewes raised at different locations. Journal of Agricultural Science, Cambridge 103, 481486.
Amir, D. & Volcani, R. (1965). The sexual season of the Awassi fat-tailed ewe. Journal of Agricultural Science, Cambridge 64, 8385.
El-Fouly, M. A., Shafie, M. M., Abdbl-Aziz, A. S. & Kandeal, S. A. (1977). Seasonal variation in oestrous activity in Ossimi and Rahmani ewes. Egyptian Journal of Animal Production 17, 7585.
Hafez, E. S. E. (1951). Sexual season of the ewe and day light environment. Nature, London 166, 822.
Hafez, E. S. E. (1952). Studies on the breeding season and reproduction of the ewe. Journal of Agricultural Science, Cambridge 42, 189265.
Lambeeson, W. R. & Thomas, D. L. (1982). Effect of season and breed of sire on incidence of oestrus and ovulation rate in sheep. Journal of Animal Science 54, 533539.
Land, R. B. (1970). Ewe fertility. Animal Breeding Research Organization Report 1970, pp. 2732.
Lees, J. L. (1971). Some aspects of reproductive efficiency in sheep. Veterinary Record 88, 8696.
Ragab, M. T. (1960). A comparative study of some foreign breeds of sheep in Tahreer Province. First Near East Meeting on Animal Production and Health, Cairo, 4–14 04 1960.
Rowell, J. G. & Walters, D. E. (1976). Analysing data with repeated observations on each experimental unit. Journal of Agricultural Science, Cambridge 87, 423432.
Sefidbakht, N., Mostafavi, M. S. & Farid, A. (1978). Annual reproductive rhythm and ovulation rate in four fat-tailed sheep breeds. Animal Production 26, 177184.
Tempest, W. M. & Boaz, T. G. (1973). The seasonality of reproductive performance of Merino sheep in Britain. Animal Production 17, 3341.
Wheeler, A. G. & Land, R. B. (1977). Seasonal variation in oestrous and ovarian activity of Finnish Landrace, Tasmanian Merino and Scottish Blackface ewes. Animal Production 24, 363376.

Oestrous activity of Suffolk, Mutton Merino and their crosses with subtropical Ossimi sheep

  • A. M. Aboul-Naga (a1), M. B. Aboul-Ela (a1) and F. Hassan (a1)

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