Effect of synchronisation of ovulation on ovarian profile and days open in holstein cows diagnosed as nonpregnant 26 days after timed artificial insemination.

The objective of this study was to clarify the effects of a second protocol of ovulation synchronisation starting on day 26 after timed artificial insemination on ovarian profile and days open in dairy cows diagnosed as nonpregnant. Ninety-four Holstein-Friesian cows received intramuscular injections of a GnRH analogue (GnRH), 100 microg fertirelin, on day 0 and a prostaglandin F(2alpha) analogue (PG), 5 mg etyprostontromethamine, on day 7. GnRH was again administered 48 h after the PG injection, and timed artificial insemination was performed 16 to 20 h later (Ovsynch/TAI). Twenty-six of the 94 cows returned to oestrus within 26 days after TAI and were inseminated. Of the other 68 cows, 44 were not pregnant and were randomly allocated to undergo another Ovsynch/TAI protocol (Resynch group; n=23) or AI only after detection of oestrus (Control group; n=21). The ovarian and hormonal profiles were compared between the first and second Ovsynch protocol periods in the Resynch group. The diameter of the dominant follicle and plasma oestradiol-17 beta concentration at the second GnRH injection were significantly greater than those at PG injection during the second Ovsynch period. Ovulation was synchronised in all of the animals in the second Ovsynch period. The AI submission rates, mean AI intervals and pregnancy rates of the Resynch and Control groups were 100% and 57.1%, 36.0 +/- 0.0 and 43.2 +/- 10.9 and 30.4% and 14.3%, respectively. The mean AI interval was 7 days shorter and the pregnancy rate was higher in the Resynch group than in the Control group, although no significant differences were found due to the small number of the animals. In conclusion, the Resynch protocol initiated on day 26 after TAI in the first protocol has the potential to reduce days open and increase the pregnancy rate in dairy cows.

Plasma and fecal sex steroid hormone profiles during the estrous cycle in a Japanese serow (Capricornis crispus).

We aimed to determine plasma progesterone and estradiol-17beta concentrations, as well as fecal progesterone concentrations during the estrous cycle in a female 8-year-old Japanese serow (Capricornis crispus). The step frequencies during the night were recorded by a pedometer attached to the serow's hind leg from October to the following June. Estrous behavior was also monitored during the day. Blood samples were taken once a day from 8 February to 10 March from an indwelling catheter placed in the jugular vein. Fecal samples were taken once or twice a day from 1 January to 29 April. Plasma and fecal progesterone and plasma estradiol concentrations were determined using time-resolved fluoroimmunoassays. The estrus behavior observed lasted for 2-3 days. Peak step frequencies were recorded between November and April, at intervals of 17-19 days. Plasma progesterone concentrations remained elevated (1-7.7 ng/ml) for 12 days during non-estrus, and plasma estradiol concentrations were highest when the peak step frequency and estrous behavior were observed. Step frequency increased around the times fecal progesterone levels fell to basal levels. Progesterone concentrations in feces were significantly correlated with those in sera. Thus, measurement of fecal progesterone concentrations might be useful for monitoring the reproductive status of the Japanese serow.