The technique of laparoscopic oocyte aspiration has been increasingly used in animals; however, there are few records of its use in buffaloes. To describe this technique, six suckling Murrah buffaloes aged between 3 and 5 months were used. Three laparoscopic ovum pick-ups were performed in each animal, with intervals of 15 days between surgeries, completing a total of 18 procedures. The technique used three surgical ports with optics and a high-definition video camera. The introduction of the first portal and insufflation of the abdomen was performed through the open technique, with aspiration using a 20 G needle transabdominally and a vacuum pump calibrated at 50 mmHg. The mean complete surgical time from anesthesia to the removal of the animal from the litter was 49 ± 9.8 min. There were 27.8% cases of insufflation on the wrong side of the omentum. The oocyte recovery rate of 60.3% remained within the normal range. However, the rate of viable oocytes recovered was low, with only 40.8% of those recovered undergoing in vitro embryo production (IVEP). These data demonstrate that this simple, minimally invasive technique is an excellent reproductive tool for the genetic improvement of buffalo species.

Platelet-rich plasma (PRP) has anti-inflammatory and regenerative properties with the potential use in advanced age mares uterine alterations. Our objective was to evaluate the effect of intrauterine PRP infusion in older embryo donor mares on embryo recovery rate. Endometrial biopsy was performed for histopathological classification, once, in 18 mares aged 18~25 years. Mares were examined routinely for estrus monitoring. During each estrus phase, uterine cytology was collected and evaluated. When a 35 mm follicle and edema ≥ 2 was detected, ovulation was induced using 1 mg deslorelin acetate, followed by intrauterine infusion, according to treatment: 1) PRP: intrauterine infusion of 5 mL of PRP, and 2) Control: intrauterine infusion of 5 mL of Lactated Ringer’s solution. Within 24 h of ovulation induction and intrauterine infusion, mares were inseminated with fresh semen and subsequently 24 h ovulation was detected. Eight days after ovulation, embryos were recovered and classified. Statistical analyses were performed using GraphPad Prism 9® software. In histological classification, IIA mares presented higher embryonic recovery rate in the PRP group than in Control (P = 0.04). In cytological evaluation, no significant difference was observed between groups. A total of 49 embryo recovery attempts were performed, in Control group recovery rate was 21.7% (5 embryos from 23 flushes) while in PRP was 34.6% (9 embryos from 26 flushes), with significant difference in PRP infusion number of recovered embryos (P = 0.04). Intrauterine infusion of autologous PRP, at the time of ovulation induction, increases the chance of embryonic recovery in older embryo donor mares.

Aim of study: To investigate the correlation between antral and preantral ovarian follicular populations in adult cattle, given the discrepant previous reports, and to evaluate this correlation for the first time in buffalo. Area of study: Amazon region, North of Brazil. Material and methods: Ovaries of non-pregnant, adult, cycling, Bubalus bubalis (n=10), Bos indicus (Nelore; n=10), and Bos indicus × Bos taurus (Nelore × Angus crossbreed; n=10) were collected at the slaughterhouse, measured, and weighed. Antral follicles were counted (AFC), and the preantral population was estimated by histology. The correlation between ACF and preantral population was analyzed within each animal group, before and after categorizing females as low or high AFC. Main results: Nelore and crossbreed presented similar ovarian morphometry results (p>0.05), while buffalo (Bubalus bubalis) had the smallest and lightest ovaries (p<0.05). Nelore showed the highest AFC (p0.05). Nelore and buffalo ovaries had similar (p>0.05) amounts of preantral follicles, while crossbreed ovaries had the largest population (p<0.05). A strong indivi-dual variation in the preantral follicular population was observed, and no correlation was observed between AFC and preantral population in any animal group, even after categorizing females as low or high AFC. Research highlights: In cattle, this study brings more evidence about the non-existence of a correlation between AFC and preantral follicular population, and, in buffalo, this is the first report in the literature eva-luating this correlation. These results add to the debate on the use of AFC as a selection method for female reproduction.