ABSTRACT The present study aimed to correlate the age and weight of Girolando heifers with uterine and ovarian development. Sixty heifers between 12 and 36 months old were weighed and subjected to ultrasound assessment to measure the diameters of each uterine horn and ovaries, monthly. These measures continued until their first ovulation. The animals were divided, for data analysis, according to their age into five groups: GI (12 to 14 months), GII (15 to 18 months), GIII (19 to 24 months), GIV (25 to 30 months), and GV (31 to 36 months). The dispersion diagram was used to assess the correlation between data collected monthly from uterus/ovaries and weight/age. An average daily growth of 0.0032 mm was recorded for the right ovary (RO) and 0.0051 mm for the left ovary (LO). The average size of the RO in GI was 17.58 mm and the LO was 15.28 mm; in GII, the RO was 16.72 mm and the LO was 15.89 mm; in GIII, the RO was 18.37 mm and the LO was 16.55 mm; in GIV, the RO was 19.09 mm and the LO was 17.49 mm; and in GV, the RO was 19.89 mm and the LO was 18.96 mm. The uterine horns showed an average daily growth of 0.0064 mm and 0.0071 mm for the right (RU) and left (LU) uterine horn, respectively. The average sizes of the uterine horns per group were: RU, 11.46 mm and LU, 11.48 mm; RU, 12.41 mm and LU, 12.63 mm; RU, 13.16 mm and LU, 13.19 mm; RU 14.30 mm and LU, 14.58 mm; and RU, 16.12 mm and LU, 16.68 mm for the groups GI, GII, GIII, GIV, and GV, respectively. The heifers showed an average daily weight gain of 0.224 kg and the groups GI, GII, GIII, GIV, and GV had an average weight of 220.5, 239.3, 287.6, 332.9, and 380.1 kg, respectively. Therefore, weight growth correlates with the growth of the ovaries and uterine horns; furthermore, these data correlate positively as the animals age.

The objective of this study was to evaluate the effect of the follicular wave synchronization method on the superovulatory response of Girolando embryo donors. Seven cows and five heifers were divided into three treatments according to the method of the follicular wave synchronization prior to superovulation. The donors were superovulated with eight FSH decreasing doses, adding 133 mg per animal. The superovulatory response was evaluated using an ultrasound device to quantify the number of corpora lutea. The number and quality of recovered structures were also evaluated. Animal category (cow or heifer) and genetic group influenced the superovulatory response, in which heifers showed a greater response (100% in all treatments) compared with cows, which showed 85.7%, 57.1% and 57.1% superovulatory response for standing estrus, GnRH and P4 + BE groups, respectively. The genetic group also showed influence on superovulatory response, in which the 3/8 animals had an average of 10.3 corpora lutea per donor compared with the 3/4 animals, which showed 4.9. The follicular wave synchronization treatments did not show differences in superovulatory response, recovered structures and viable structures. The treatment of follicular wave synchronization with GnRH or with P4 + BE can be used in Girolando donors with the same efficiency as the standing estrus group, and 3/8 Girolando heifers respond better to the superovulatory treatment.

The objective of this study was to evaluate the reproductive parameters of Sindhi cows aiming to improve the efficiency of fixed-time artificial insemination protocols in this breed. For this purpose, sixteen Sindhi cows were divided into two groups: in group I (EB, n = 8) animals received an intravaginal P4 implant and an application of 2 mg of estradiol benzoate on day 0. On day 8 the implant was removed and 10 mg of Dinoprost were applied; on day 9, 1 mg of estradiol benzoate was applied, and animals were fixed-time artificially inseminated 36 hours later; in group II (EB + eCG, n = 8) animals were subjected to same treatment, and on day eight 400 IU of eCG were applied. From day 0 animals were examined daily by a trans-rectal ultrasound device, where in each assessment the largest follicles of each day were measured. The reproductive parameters observed for groups I and II were: emergence of follicular wave, 4.5±1.4 and 3.8±0.3 days; interval between wave emergence and ovulation, 5.8±1.4 and 7.1±0.3 days; interval between wave emergence and implant removal, 3.5±1.4 and 4.1±0.3 days; interval between implant removal and ovulation, 74.0±11.8 and 82.5±4.2 hours; diameter of the dominant follicle (DF) at the time of implant removal, 7.5±2.5 and 6.6±1.5 mm; maximum diameter of DF, 10.47±8.85 and 3.7±1.2 mm; growth rate of DF, 0.90±0.83 and 0.7±0.6 mm/day; ovulation rate, 75% and 100%; and pregnancy rate, 0% and 50%, respectively. There was no significant difference between the groups. We observed that eCG was not efficient in improving the reproductive parameters analyzed in this breed.