[Postpartum ovarian activity in primiparous Holstein dairy cows]

Postpartum anestrus is a major problem in primiparous dairy cows. The objective of this study was to investigate postpartum ovarian activity in primiparous Holstein dairy cows. Seven primiparous Holstein dairy cows were monitored for ovarian activity using a combination of ultrasound examination and alteration in progesterone concentrations. Daily blood sampling and ultrasound examination were conducted starting from day 6 until the third ovulation postpartum. First wave dominant follicles [>/= 10 mm in diameter] were detected on day 11.5 +/- 1.48 postpartum. This follicle did not ovulate in any of the experimental cows. Moreover, none of the cows ovulated within 20 days postpartum. There was no difference in the follicular growth rate and the diameter of ovulatory follicles between the first, the second and the third ovulations postpartum [p>0.05]. Interval from calving to the firstpostpartum ovulation was 48.1 +/- 6.89 days. Mean diameter of corpus luteum and progesterone concentrations of the first cycle [18.8 +/- 0.94 mm and 2.0 +/- 0.24 ng/mL] were significantly less than those of the second cycle [24.0 +/- 0.89 mm and 3.6 +/- 0.36 ng/mL; p<0.05]. In conclusion, increased interval from parturition to the first ovulation is not due to the delayed or lack of the first wave dominant follicle formation after parturition; but is due to the regression of this follicle

[ effect of norgestomet implant on follicle development in bactrian camel]

Progestagens have been used in order to control follide wave dynamics in camelids, however, the results are contra versial. The purpose of this study was to investigate the effect of single norgestomet implant on ovarian follicle development in Bactrian camel. Bactrian camels [n=8; 6-14 years old] were assigned randomly to two groups. Norgestomet treated group [n=4] received one implant of norgestomet under the skin of ear for 10 days [Day 0= Day of implant insertion]. Camels in Control group [n=4] did not receive any treatment. Daily ultrasound examination using trans-rectal linear probe was conducted to determine ovarian follicle status. Mature follicle was defined as a growing follicle at the size of 13-17mm in diameter. In both groups, there was a female with a persistent follicle throughout the experiment and a new emergence of follicle wave on Day 6-7 of the experiment. The latter follicle did not reach mature size on Day 10 of experiment. In both groups, there was a female with growing follicle during the experiment that became at the range of mature size at the termination of study. In both groups, there was a female with a regressing follicle throughout the experiment and a growing follicle which become mature during 10 days of treatment. One female in Control group had a persistent follicle throughout the experiment and a new emergence on Day 9. One female in Norgestomet treated group, had a persistent follicle during experiment and a growing follicle that ovulated spontaneously between Days 9 and 10 of experiment. In conclusion, single Norgestomet implant for 10 days does not regulate ovarian follicle development in Bactrian camel

effect of LH and GnRH analogues on induction ovulation in Bactrian camel [Camelus bactrianus]

Ovarian follicle response and corpus luteum formation following induction of ovulation using gonadotropin-releasing hormone [GnRH] analogues and luteinizing hormone [LH] in Bactrian camel were characterized. Bactrian camels with a mature follicle [13-19.6 mm] received: 1] natural porcine LH [25 mg, IV, n = 4], 2] Buserelin [20 microg, IV, n = 4] and 3] Alarelin [25 microg, IM, n = 4]. Daily ultrasonography and blood samplings were conducted between day -3 and +15 of the experiment [day 0 = Induction of ovulation]. Data were analyzed by univariat analysis with repeated measures analysis included in the model. Following treatment, mature follicle ovulated within 2 days and a new follicle wave emerged after 2-3 days. New mature follicle reached a size of 13.5 +/- 0.14 mm by day 12. Corpus luteum was detected on day 6 and reached the maximum size of 19.73 +/- 0.81 mm on day 9. Progesterone concentration initiated to increase on day 5, reached maximum concentration on day 9 and decreased significantly on day 11. In conclusion, due to the lack of significant difference among treatment groups [P>0.05], Alarelin may be considered as a drug of choice for inducing ovulation in Bactrian camel because of its effectiveness, simple route of administration [IM vs. IV], lower price, and local availability