
%0 Journal Article
%A Davis, SR 
%A Smith, JF 
%A Gluckman, PD 
%T Effects of growth hormone injections on ovulation rate in ewes
%J Reproduction, Fertility and Development
%D 1990/04/01
%V 2
%N 2
%P 173-178
%K 
%R https://doi.org/10.1071/RD9900173
%U https://www.publish.csiro.au/paper/RD9900173 
%X Coopworth ewes were either treated with 5 mg recombinant-derived bovine growth hormone per day for each day of the oestrous cycle or were untreated. Ovulation rates at the pre-treatment, post-treatment and a subsequent oestrus were determined by endoscopy. These were 1.34, 1.51, 1.38 for the treated ewes and 1.32, 1.43, 1.39 for the control ewes. The ovulation rate post-treatment was significantly higher than for the other two cycles in the treated ewes but it was not significantly different from the post-treatment value of the control ewes. Plasma concentrations of insulin-like growth factor-I (IGF-I) were elevated during treatment (90-130 nmol L-1) compared with concentrations of 25-50 nmol L-1 in the control ewes. No relationship was found between plasma IGF-I concentration and ovulation rate. Injection of ewes grazing ryegrass/white clover pasture with bovine growth hormone did not result in increased ovulation rate. 
