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Biomedical subjects

W R Dukelow

Publications and source records attributed to W R Dukelow.

At least 91 records · Page 5Linked to original sources

Induction of multiple ovulation in the cow with single injections of FSH and HCG.

A gonadotrophin regimen was developed to induce a high incidence of double and triple ovulations in the beef cow using a single injection of FSH on Day 16 followed by a low dose of HCG on the day of oestrus. Conception rate was not affected by gonadotrophin treatment and 1/9 cows experiencing multiple ovulations gave birth to twin calves.

Animals↗

The morphology of follicular development and ovulation in non-human primates.

A colony of Macaca fascicularis have been under continuous observation for the past 4 years to ascertain the follicular morphological changes that occur prior to ovulation and during the development of the corpus luteum. Of 609 experimental cycles, laparoscopy was performed at least once in 44-5% of the cycles. Of the 104 cycles where the ovulatory status was definitely known, 89-4% were deemed ovulatory and 10-6% anovulatory. The presence or absence of ovulation in the previous cycle did not have an effect on the cycle length either for the total cycles or when analysing only cycles over 28 days. Similarly, the occurrence of two consecutive ovulations (in consecutive cycles) on the same vs. opposite ovaries did not have a significant effect on the cycle length. Neither laparoscopic stress or anaesthesia effected the normal cyclicity of the animals. The characteristic changes in follicular morphology are most clearly defined in M. fascicularis. In this species the 24 of 36 hr prior to ovulation are accompanied by discrete changes which occur in a fixed sequence, allowing one to predict the time of ovulation with reasonable accuracy. In S. sciureus ovulation is preceded by extensive bulging at the follicular apex and haemorrhaging at the base of the follicle. Due to this haemorrhaging post-ovulatory follicles in S. sciureus are generally more easily discernible than in fascicularis. The formation of clear areas (stigma) is not as evident in either S. sciureus or G. senegalensis as in the macaque. Actual ovulation has been observed four times in M. fascicularis and twice in S. sciureus.

Animals↗