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Effect of shearing on oestrus and ovulation in sheep

Published online by Cambridge University Press:  27 March 2009

R. A. Parr
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030
I. F. Davis
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030
A. J. Tilbrook
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030

Extract

Shearing causes a rapid increase in plasma cortisol concentrations (Kilgour & de Langen 1970; Purchas 1973; Fulkerson & Jamieson 1982), indicating that acute physiological responses are associated with the procedure. Environmental stress before mating can result in a delay in the onset of oestrus (Doney et al. 1973) and a reduction in ovulation rates (Doney et al. 1976). Dobson (1988) demonstrated that shearing caused a reduction in the luteinizing hormone (LH) response to exogenous gonadotrophin releasing hormone (GnRH) in anoestrous ewes. Such a response to shearing could influence the incidence of oestrus and ovulation.

Type
Short Note
Copyright
Copyright © Cambridge University Press 1989

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References

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