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Biomedical subjects

J F Roche

Publications and source records attributed to J F Roche.

At least 145 records · Page 8Linked to original sources
PubMed1977

Control of ovulation and fixed time insemination in heifers following cloprostenol.

The time of ovulation was determined in heifers following two injections 11 days apart of 500 microgram of cloprostenol by recovery of reproductive tracts at slaughter. Ovulation had not begun by 72 hours while 31%, 61% and 95% had ovulated by 78, 92 and 96 hours respectively after the second injection of cloprostenol. Injection of synthetic LH-releasing factor (GnRH) given 48 hours after cloprostenol significantly hastened the time of ovulation in animals slaughtered at 78 hours after the second cloprostenol injection. Insemination of heifers at 48, 60 or 72 hours resulted in lower fertility than two inseminations at 60 and 72 hours or at 48 and 72 hours after treatment. Controlling the time of ovulation with GnRH did not increase the fertility following a single insemination 71 hours after the treatment with cloprostenol.

Animals↗
PubMed1976

Comparison of pregnancy rate in heifers and suckler cows after progesterone or prostaglandin treatments.

The pregnancy rate in 321 Friesian dairy replacement heifers was not different following two inseminations on a fixed time basis when oestrus was synchronised with either a 12-day progesterone treatment using silastic coils or a double injection regimen of a synthetic analogue of prostaglandin f2alpha (chloprostenol). There was a significantly higher (P less than 0-01) pregnancy rate following insemination when 143 Hereford-cross beef suckler cows were treated with the 12-day progesterone treatment (55 per cent pregnant) in comparison to the pregnancy rate following insemination of 131 cows receiving the double injection of cloprostenol 12 days apart (32 per cent pregnant). The ovarian activity at the start of treatment affected pregnancy rate following the cloprostenol regimen but not following the progesterone regimen. In suckler cows in these trials where ovarian activity was classified at the start of treatment, 30 per cent had inactive ovaries, indicating the magnitude of the problems of synchronising oestrus in beef suckler cows.

Animals↗
PubMed1976

Fertility in cows after treatment with a prostaglandin analogue with or without progesterone.

Two infections each of 500 mug Cloprostenol (ICI-80,996), a synthetic analogue of PGF-2alpha, 11 or 12 days apart or pretreatment for 7 days with progesterone from an intravaginal silastic coil and one injection of 500 mug Cloprostenol were both effective in synchronizing oestrus in heifers or nursing beef cows. After two inseminations at 72 and 96 hr after the end of treatment, the calving rate for cows observed in oestrus after both treatments or for cows that had oestrous-like mucus after the progesterone+Cloprostenol treatment did not differ from that of control cows, but was significantly (P less than 0-025) lower for cows diagnosed as ready for insemination by the characteristics of mucus after the two injections of Cloprostenol. Treated cows disgnosed per rectum as having inactive ovaries had a significantly (P less than 0-005) lower calving rate than those diagnosed as having active ovaries at the start of treatment. Significantly (P less than 0-005) more treated than control cows were inseminated and became pregnant in the first 15 days of the treatment period, but the overall level of reproductive efficiency was low.

Animals↗
PubMed1975

Control of time of ovulation in heifers treated with progesterone and gonadotrophin-releasing hormone.

The time of ovulation was determined in twenty-nine heifers by laparoscopy following treatment with progesterone. In addition, twenty-five of the animals received 100 mug Gn-RH 30 hr after the end of the progesterone treatment. Only eight of the heifers treated with Gn-RH ovulated. This contrasted with results obtained following examination of ovaries after slaughter in similar animals treated in identical fashion. Heifers which were treated with progesterone for 12 days and then slaughtered had not begun to ovulate 65 hr after the end of treatment, but five of eleven animals had ovulated 4 hr later. When Gn-RH was given, ovulation had started 60 hr after the end of progesterpme treatment, 60% of heifers had ovulated at 65 hr and 90% at 69 hr. Treatment with Gn-RH can synchronize and hasten the time of ovulation in heifers given progesterone. Possible reasons for the discrepancy between the results obtained following laparoscopy and slaughter are discussed.

Animals↗