Stress is known to result in lowered female reproductive efficiency. The objective of this study was to examine how increased pituitary-adrenal activity may influence gonadotrophin release in anoestrous ewes. Various doses (0.06-1.0 mg) of a synthetic adrenocorticotrophic hormone (ACTH(1-24)) preparation were injected into ewes 30 min or 3 h before an i.v. injection of 500 ng gonadotrophin-releasing hormone (GnRH). The LH response to GnRH given 30 min after ACTH(1-24) was similar to that after GnRH alone, whereas the response 3 h after ACTH(1-24) was significantly lower, irrespective of the dose of ACTH(1-24). At 30 min and 3 h after ACTH(1-24) the concentrations of cortisol exceeded 50 nmol/l compared with baseline values of less than 10 nmol/l. The effect of ACTH(1-24) on oestradiol-induced LH release was also examined. Those ewes receiving 0.8 mg ACTH(1-24) depot and 50 micrograms oestradiol benzoate simultaneously had a preovulatory-type increase in LH 14-20 h later, similar to when oestradiol benzoate was given alone. None of the ewes receiving an additional 0.8 mg ACTH(1-24) depot 10 h after oestradiol benzoate had increases in LH concentration. The cortisol concentrations in all ewes receiving either one or two injections of ACTH(1-24) were greater than 35 nmol/l at 10 h after the oestradiol injection. However, concentrations of progesterone increased from 0.9 +/- 0.3 (S.E.M.) nmol/l at the time of the second ACTH(1-24) injection to 2.1 +/- 0.3 nmol/l after 2 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Doses of 0.005-1.0 mg of ACTH1-24 given intravenously, intramuscularly or as an intramuscular depot injection caused increases in cortisol concentrations within 15 min in the plasma of ewes. There was, however, considerable animal-to-animal variation in maximum concentrations achieved. A curvilinear dose-response relationship to ACTH1-24 was obtained which was similar for each route of administration when expressed in terms of maximum cortisol concentrations. However, for a given dose, more prolonged release of cortisol occurred after i.m. injection compared to i.v., with maximum concentrations occurring 6 h after the depot formulation injection. Five repeated daily doses of 1.0 mg depot ACTH1-24 resulted in no diminution of cortisol response indicating considerable synthesizing capacity of the adrenals in clinically normal ewes. Comparison of cortisol concentrations after an acute stressor (shearing) suggests that doses of ACTH1-24 greater than 0.25 mg are excessive for simulation of stress-induced adrenal activity.

The study was investigated to compare the effectiveness of Folltropin and two products (Fostimon and Menogon) of a recombinant human follicle stimulating hormone (rhFSH) on ovarian super-stimulation and embryo production in dairy Holstein cows. Two different doses for each super-ovulatory product were investigated. The relationship between the levels of Anti-Mullerian Hormone (AMH) in the blood serum before super-stimulation initiation and ovarian response and embryos production were also evaluated. At random stage of the estrus cycle, the donor cows were received intra-vaginal controlled internal drug release device (CIDR) and injected with 100µg of gonadotropin-releasing hormone (GnRH). On fourth day of CIDR insertion, cows were divided according to the product types of superovulatory hormones into three equal main groups. According to hormonal dose, each main group was re-divided into two equally subgroups ; low and high dose. Superovulatory hormones was injected IM as decreasing doses; 40%, 30%, 20% and 10% of the total dose twice daily for 4 days. On day 7, CIDRs were removed and each cow received 2 doses of PGF 2 α with 12hr interval. Based upon heat detection, donor's cows were inseminated with frozen semen three times 8-10hrs interval and concurrent with 100µg GnRH injection at first insemination. Non-surgical embryos recovery was performed on day's 7-8 post insemination and ovarian super-stimulation was checked using sonography to estimate ovarian response. Recovered embryos were morphologically evaluated as grades. Twelve embryos collected from Menogon donors group were transferred to six recipient's cows. The mean numbers of CL, recovered embryo/ova, fertilized ova and transferable embryos are significantly (P<0.01) higher in Folltropin and Menogon treated cows than Fostimon group. Donor cows treated with high doses of Folltropin and Menogon showed higher means for transferable and freezable embryos. Three recipients (50%) who received embryos appeared pregnant and one of them born calf. Significant positive correlations were reported between AMH on one side and CL, total ovarian response, transferable and freezable embryos on the other side, and cows having AMH≥230ng/L exhibited significant higher means. In conclusion: Menogon can be used as rhFSH for embryos production with transferable quality. AMH can be used as indicator to helpful select cow's candidates as donors. More studies are needed using Fostimon accompanied with different levels of LH.