The follicular dynamics was evaluated by ultrasonography in Brown Swiss cattle subjected to a protocol of synchronization of estrus with progestogens in the Peruvian highlands. Three groups of Brown Swiss cattle of nine females each were evaluated. The groups were: lactating cows (<120 and >260 days in milk) and heifers. For synchronization, on day 0 a progesterone-based intravaginal device was applied, and 2 mg estradiol benzoate was injected, on day 8 the device was removed and 0.15 mg cloprostenol and 400 IU eCG were applied, and on day 10 1.05 mg GnRH was applied. Artificial insemination at fixed time was done 12 h after the application of GnRH. The ultrasound evaluation was done on days 8 and 10 to determine the growth rate and maximum diameter of the dominant follicle in the three groups. The follicular growth rate was 2.3 ± 1.5, 2.4 ± 1.8 and 2.3 ± 1.8 mm/day for the grou...

The ovarian follicular dynamics monitored by transrectal (TR) and transvaginal (TV) routes in successive waves was studied in 10 llamas older than 4 years, multiparous, without calves at foot, body condition of 3.0, during a period of 90 days in the reproductive season. The Sonostar SS8® ultrasound equipment was used with a linear transducer for transrectal examination and endocavitary microconvex transducer for transvaginal examination, both with a frequency of 6.5 MHz. The inter-wave interval was 20 ± 4.4 and 22.5 ± 5.3 via TR and VT, respectively; the number of follicles per cohort was 5.21 ± 0.92 and 6.38 ± 1.26 for TR and TV, respectively (p=0.0011); the maximum diameter of follicles was 12.49 ± 3.57 mm for TR and 13.56 ± 3.91 mm for TV; the growth rate was 0.70 ± 0.35 and 0.67 ± 0.32 mm/day for TR and TV, respectively. The regression equation for the ratio of the maximum f...

The follicular dynamics was evaluated by ultrasonography in Brown Swiss cattle subjected to a protocol of synchronization of estrus with progestogens in the Peruvian highlands. Three groups of Brown Swiss cattle of nine females each were evaluated. The groups were: lactating cows (<120 and >260 days in milk) and heifers. For synchronization, on day 0 a progesterone-based intravaginal device was applied, and 2 mg estradiol benzoate was injected, on day 8 the device was removed and 0.15 mg cloprostenol and 400 IU eCG were applied, and on day 10 1.05 mg GnRH was applied. Artificial insemination at fixed time was done 12 h after the application of GnRH. The ultrasound evaluation was done on days 8 and 10 to determine the growth rate and maximum diameter of the dominant follicle in the three groups. The follicular growth rate was 2.3 ± 1.5, 2.4 ± 1.8 and 2.3 ± 1.8 mm/day for the grou...

The ovarian follicular dynamics monitored by transrectal (TR) and transvaginal (TV) routes in successive waves was studied in 10 llamas older than 4 years, multiparous, without calves at foot, body condition of 3.0, during a period of 90 days in the reproductive season. The Sonostar SS8® ultrasound equipment was used with a linear transducer for transrectal examination and endocavitary microconvex transducer for transvaginal examination, both with a frequency of 6.5 MHz. The inter-wave interval was 20 ± 4.4 and 22.5 ± 5.3 via TR and VT, respectively; the number of follicles per cohort was 5.21 ± 0.92 and 6.38 ± 1.26 for TR and TV, respectively (p=0.0011); the maximum diameter of follicles was 12.49 ± 3.57 mm for TR and 13.56 ± 3.91 mm for TV; the growth rate was 0.70 ± 0.35 and 0.67 ± 0.32 mm/day for TR and TV, respectively. The regression equation for the ratio of the maximum f...