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 aim of this study was to evaluate the factors that affect the transfer of embryos obtained through simple ovulation in alpacas and transferred to alpacas and llamas. The study was conducted under conditions of the Peruvian Highlands during the reproductive season (December to March). Thirteen donor alpacas (Huacaya = 6, Suri = 7) and 80 recipients (40 alpacas and 40 llamas) with at least 15 postpartum days were selected. The embryo recovery rate in 93 consecutive washes were 88.68% in Huacaya alpacas and 80% in Suri alpacas, and the pregnancy rates were 67.57 and 66.67% in alpacas and llamas, respectively without significant differences in both cases. The variables size and quality of the embryo, location and area of the corpus luteum (CL) in the recipient, species of the recipient (llama, alpaca), donor breed (Huacaya, Suri), body condition score (BCS) of the receptor, depth of the ...

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 aim of this study was to evaluate the factors that affect the transfer of embryos obtained through simple ovulation in alpacas and transferred to alpacas and llamas. The study was conducted under conditions of the Peruvian Highlands during the reproductive season (December to March). Thirteen donor alpacas (Huacaya = 6, Suri = 7) and 80 recipients (40 alpacas and 40 llamas) with at least 15 postpartum days were selected. The embryo recovery rate in 93 consecutive washes were 88.68% in Huacaya alpacas and 80% in Suri alpacas, and the pregnancy rates were 67.57 and 66.67% in alpacas and llamas, respectively without significant differences in both cases. The variables size and quality of the embryo, location and area of the corpus luteum (CL) in the recipient, species of the recipient (llama, alpaca), donor breed (Huacaya, Suri), body condition score (BCS) of the receptor, depth of the ...

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 aim of this study was to evaluate the effect of the sexual behaviour process of copulation with castrated males (G1) on ovulation induction, contrasting with the same effect of vasectomized males (G2) and the effect of the application of seminal plasma (G3) in utero in 45 alpacas with preovulatory follicle ≥7 mm in diameter, randomly distributed (n=15) in each experimental group. The occurrence of ovulation was estimated on day 4 post-copula by sexual receptivity (acceptance or rejection) to the male and verified on days 7 and 11 with the detection of a corpus luteum (CL) by transrectal ultrasound. In G1, seminal plasma secretion was determined on days -1, 1, 17 and 21 after castration. The phases of sexual behaviour in the controlled mating were similar between G1 and G2. On day 4 post mating a female from G1 had ovulated. On day 7, the ovulation rate determined by the presence of...

The aim of this study was to determine the effect of three freezing curves on the post-thaw viability of spermatozoa collected from the vas deferens of llamas. Six male llamas with surgical diversion of the vas deferens were used. The samples of the six males were mixed for processing (pools) and diluted with Tris-egg yolk. Cooling was carried out to 5 °C where the dilution was completed (dilutor with glycerol) and was maintained for 30 minutes (equilibrium phase). Samples in 0.25 ml straws were subjected to freezing using a temperature drop rate of -20°C/min until reaching -80°C (TI), -100°C (TII) and -120°C (TIII) in 4, 5 and 6 minutes, respectively, to finally store them in liquid nitrogen. The samples were collected for three months (n=19 pools). Total motility (progressive, circular, oscillatory motility), viability and membrane functionality were determined after collection, i...