Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-25T06:55:16.096Z Has data issue: false hasContentIssue false

The effect of sudden introduction of rams on oestrus pattern of tropical ewes

Published online by Cambridge University Press:  27 March 2009

L. O. Ngere
Affiliation:
University of Ghana, Legon
J. M. Dzakuma
Affiliation:
University of Ghana, Legon

Summary

Observations were made over a period of 3 years on a total of 331 Nungua Black Head and 104 West African Dwarf sheep. It was shown that ewes of these breeds responded strongly to stimulation occasioned by the sudden introduction of rams which had been separated from them for 10 months. Sudden ram presence apparently altered the normal oestrous cycle of a substantial number of ewes which unlike temperate breeds showed behavioural oestrus soon after being run with the rams resulting in about a quarter of the flock being bred on the first day of association with the ram. This behavioural oestrus must have been accompanied by ovulation as shown by the lambing records 5 months later. The observations also suggested the existence of breed differences in the degree of ewe response to sudden ram presence.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1975

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

REFERENCES

Ababio, L. N. K. (1969). Proceedings of the 1969 Animal Science Symposium. University of Ghana, Legon.Google Scholar
Dyrmundsson, O. R. & Lees, J. L. (1972). Effect of rams on the onset of breeding activity in Clun Forest ewe lambs. Journal of Agricultural Science, Cambridge 79, 269–71.CrossRefGoogle Scholar
Dzakuma, J. M. (1972). Observations on the mating activity of the Nungua Black head and Forest type sheep. Unpublished B.Sc. dissertation, University of Ghana, Legon.Google Scholar
Jollans, J. L. (1960). A study of West African Dwarf sheep in the closed forest zone of Ashanti. West African Journal of Biological Chemistry 3, 77.Google Scholar
Lasley, J. F. (1968). In Reproduction in Farm Animals (ed. Hafez, E. S. E.). Philadelphia: Lea and Febiger.Google Scholar
Lishman, A. W. (1969). The seasonal pattern of oestrus among ewes as affected by isolation from and joining with rams. Agroanimalia 1, 95101 (A.B.A. 2013).Google Scholar
Mason, I. L. (1951). The classification of West African Livestock (Technical Communication No. 7). Farnham Royal, CAB.Google Scholar
Schinckel, P. G. (1954 a). The effect of the ram on the incidence and occurrence of oestrus in ewes. Australian Veterinary Journal 30, 189–95.CrossRefGoogle Scholar
Schinckel, P. G. (1954 b). The effect of the presence of the ram on the ovarian activity of the ewe. Australian Journal of Agricultural Research 5, 465–9.CrossRefGoogle Scholar
Williamson, G. & Payne, W. J. A. (1959). Animal Husbandry in the Tropics. London: Longmans, Green and Co.Google Scholar
Wilson, A. S. B. (1965). In Annual Report 1965–66. University of Ghana Agricultural Research Station, Nungua.Google Scholar