Cravinhos, Brazil
Cravinhos, Brazil
Time filter
Source Type

Gimenes L.U.,São Paulo State University | Ferraz M.L.,Vida Reprodutiva Consultoria | Fantinato-Neto P.,University of Sao Paulo | Chiaratti M.R.,Federal University of Santa Catarina | And 7 more authors.
Theriogenology | Year: 2015

The aim of the present study was to determine the optimal phase of the follicular wave to perform ovum pickup (OPU) for invitro embryo production (IVEP) in various genetic groups. For this purpose, 27 heifers-nine Bos taurus (Holstein), nine Bos indicus (Nelore), and nine Bubalus bubalis (Mediterranean)-were maintained under the same nutritional, management, and environmental conditions. Heifers within each genetic group were submitted to six consecutive OPU trials with 14-day intersession intervals, at three different phases of the pharmacologically synchronized follicular wave (Day 1, 3, or 5 after follicular wave emergence), in a 3×3 crossover design. When OPU was performed at different phases of the pharmacologically synchronized follicular wave (Day 1, 3, or 5), no differences were found in the percent of oocytes recovered (70.5±3.1%, 75.0±3.1%, 76.0±3.2%, respectively; P=0.41) or blastocyst production rates (19.4±2.9%, 16.6±2.9%, 15.9±2.6%, respectively; P=0.36). Comparing genetic groups, B indicus showed a higher blastocyst rate (28.3a±2.8%; P<0.01) than B taurus and B bubalis (14.1b±2.9% and 10.2b±2.0%, respectively). However, only B indicus heifers showed a variation in the number of visualized follicles and the total and viable oocytes along consecutive OPU sessions. In conclusion, different phases of the pharmacologically synchronized ovarian follicular wave did not affect OPU-IVEP in B indicus, B taurus, and B bubalis heifers. Additionally, B indicus heifers showed greater OPU-IVEP efficiency than did the other genetic groups, under the same management conditions. © 2015 Elsevier Inc.

Ferraz M.L.,Vida Reprodutiva Consultoria S S LTDA | Ferraz M.L.,University of Sao Paulo | Sa Filho M.F.,University of Sao Paulo | Batista E.O.S.,University of Sao Paulo | And 8 more authors.
Animal Reproduction Science | Year: 2015

The aim of the present study was to evaluate the effect of bovine somatotropin (bST; 500mg) administration on lactating buffalo donors submitted to two different ovum pick-up (OPU) and in vitro embryo production schemes with a 7 or 14d intersession OPU intervalA total of 16 lactating buffalo cows were randomly assigned into one of four experimental groups according to the bST treatment (bST or No-bST) and the OPU intersession interval (7 or 14d) in a 2×2 factorial design (16 weeks of OPU sessions)The females submitted to OPU every 14d had a larger (P<0.001) number of ovarian follicles suitable for puncture (15.6±0.7 vs12.8±0.4) and an increased (P=0.004) number of cumulus-oocyte complexes (COCs) recovered (10.0±0.5 vs8.5±0.3) compared to the 7d interval groupHowever, a 7 or 14d interval between OPU sessions had no effect (P=0.34) on the number of blastocysts produced per OPU (1.0±0.1 vs1.3±0.2, respectively)In addition, bST treatment increased (P<0.001) the number of ovarian follicles suitable for puncture (15.3±0.5 vs12.1±0.4) but reduced the percentage (18.9% vs10.9%; P=0.009) and the number (1.4±0.2 vs0.8±0.1; P=0.003) of blastocysts produced per OPU session compared with the non-bST-treated buffaloesIn conclusion, the 14d interval between OPU sessions and bST treatment efficiently increased the number of ovarian follicles suitable for punctureHowever, the OPU session interval had no effect on embryo production, and bST treatment reduced the in vitro blastocyst outcomes in lactating buffalo donors © 2015 Elsevier B.V.

Ferreira R.M.,University of Sao Paulo | Macabelli C.H.,University of Sao Paulo | de Carvalho N.A.T.,APTA | Soares J.G.,University of Sao Paulo | And 9 more authors.
Buffalo Bulletin | Year: 2013

Buffaloes and bovines are polyestrous and seasonal or annual livestock, respectively, that show reduced fertility during heat stress. To investigate whether reduced fertility is related to oocyte competence in both species, immature oocytes from buffalo and bovine heifers were collected during winter and summer and subjected to molecular analyses. In each season, heifers of both species had their follicular wave emergence synchronized with a standard protocol (Ferreira et al., 2011). Before being subjected to ovum pick up (OPU), cutaneous (CT; °C) and rectal (RT; °C) temperatures and respiratory rate (RR; breaths/min) were measured. Oocytes' RNA was extracted to evaluate the expression of target genes related to mtDNA replication/transcription (PPARGC1A, TFAM and MTCO1), apoptosis (BAX and BCL2) and HS (HSP90AA1 and HSPA1AB). ACTB, HIST1H2AG and GAPDH were initially chosen as housekeeping genes. In buffaloes, CT (35.0±0.4 vs 23.8±0.5), RT (38.7±0.1 vs 38.0±0) and RR (21.3±1.2 vs 15.4±1.1) were higher during summer than winter. However, in bovine heifers, RT (38.7±0.1 vs 38.6±0.1) and RR (44.8±1.5 vs 40.6±1.5) were similar in both seasons, while CT (31.6 ±0.3 vs 30.2±0.3) was increased during summer. Reduced expression of ACTB, HIST1H2AG and GAPDH was evidenced during summer, disqualifying them as housekeeping genes. Similarly, the expression of all target genes was reduced during summer in oocytes of both species. In summary, physiological responses to heat stress seem to be more intense in buffalo than bovine heifers. However, in both species, negative effects of heat stress upon oocyte quality occur at the molecular level and affects genes related to several biological functions.

Loading Vitrogen collaborators
Loading Vitrogen collaborators