71 Effect of follicle-stimulating hormone dose and circulating progesterone before ovum pickup and invitro embryo production in pregnant Holstein heifers

2021 ◽  
Vol 33 (2) ◽  
pp. 143
Author(s):  
C. Hayden ◽  
R. V. Sala ◽  
D. C. Pereira ◽  
L. C. Carrenho-Sala ◽  
M. Fosado ◽  
...  

Superstimulation with exogenous FSH before ovum pickup for invitro embryo production (IVP) improves embryo production. However, there is limited information on different FSH dose regimens and the effect of progesterone (P4) concentrations on IVP. Thus, the objective of the present study was to evaluate the effect of FSH dose and circulating P4 on ovarian superstimulation responses, before ovum pickup (OPU) on IVP in pregnant heifers. Pregnant Holstein heifers (n=47) 19.5±0.3 months of age with moderate body condition score (3.3±0.03; scale 1 to 5) were randomly assigned to 2 treatment groups, p-FSH (Folltropin-V, Vetoquinol) 160mg (FSH160) or p-FSH 300mg (FSH300), in a crossover design. Two sessions of OPU were performed on each animal at 48 and 62 days of gestation, with a washout interval between sessions of 14 days. Dominant follicle removal (DFR) was utilised to synchronize follicular wave emergence, and FSH treatments were initiated 36h later. Heifers in both groups received a total of 4 FSH injections 12h apart as follows: FSH160 (48.0, 42.7, 37.3, and 32.0mg) or FSH300 (90.0, 80.0, 70.0, and 60.0mg). All heifers underwent OPU 40h after the last FSH treatment. Blood samples were collected for P4 quantitation at OPU and number of small (<6mm), medium (6–10mm), and large (>10mm) follicles were determined before OPU. Cumulus–oocyte complexes (COCs) recovered were processed and invitro embryo production was performed using standard procedures. Differences between treatment groups were evaluated using generalized linear mixed models, and data are presented as mean±s.e.m. (Table 1). Heifers treated with 300mg of p-FSH had a greater (P<0.05) number of medium-size follicles, total number of follicles, total COCs recovered, number of viable COCs, and number of blastocysts produced. In addition, heifers treated with 300mg of p-FSH had a greater cleavage rate (P=0.03). Circulating P4 was on average 10.1±0.4ng mL−1 and did not differ between gestation days (P=0.12). Furthermore, circulating P4 did not affect (P>0.10) any of the outcomes evaluated, nor was there an FSH dose by circulating P4 interaction (P>0.05). In conclusion, increasing the dose of p-FSH before OPU from 160 to 300mg resulted in an increase in the total number of follicles, number of oocytes, and number of blastocysts produced in pregnant donors without changes in blastocyst rate, regardless of progesterone concentrations at the time of OPU. Table 1. Ovum pickup and invitro embryo production in pregnant heifers treated with different doses of p-FSH Item FSH160 FSH300 P-value Small follicles (n) 5.0±0.6 3.5±0.4 0.02 Medium follicles (n) 14.4±0.8 18.3±0.9 0.0003 Large follicles (n) 2.9±0.3 2.5±0.3 0.28 Total follicles (n) 22.3±0.7 24.3±0.9 0.04 Total oocytes (n) 12.8±0.7 14.7±1.0 0.02 Recovery rate (%) 56.2±2.1 59.7±2.7 0.20 Viable oocytes (n) 11.4±0.7 13.3±1.0 0.02 Viable oocytes (%) 89.9±1.7 88.0±2.4 0.22 Cleavage rate (%) 63.8±4.3 71.5±3.7 0.03 Cleaved oocytes (n) 7.2±0.7 9.3±0.9 0.14 Blastocysts (n) 2.7±0.4 3.6±0.7 0.02 Blastocyst rate (%) 22.0±3.3 22.4±3.6 0.74

2021 ◽  
Vol 33 (2) ◽  
pp. 170
Author(s):  
J. C. L. Motta ◽  
R. V. Sala ◽  
V. A. Absalón-Medina ◽  
V. C. Fricke ◽  
M. Dominguez ◽  
...  

Ovarian follicle stimulation with exogenous FSH before ovum pickup (OPU) in Bos taurus females is a common practice to increase invitro embryo production (IVP). The optimal stimulatory period length for OPU-IVP, however, has not been definitively ascertained. The objective of the present study, therefore, was to determine the effect of length of the superstimulatory treatment period before OPU on ovarian response and IVP in Holstein heifers. Nonpregnant heifers (n=57) 13.8±0.2 months of age with moderate body condition score (3.0±0.1; scale 1 to 5) were assigned in a completely randomised design to one of the following experimental groups: FSH2d: 200mg of p-FSH (Folltropin-V®, Vetoquinol) distributed in four injections (60, 60, 40, and 40mg) of FSH 12h apart; FSH3d: 200mg of p-FSH distributed in six injections (40, 40, 40, 40, 20, and 20mg) of FSH 12h apart. Timing of follicular wave emergence was synchronized by dominant follicle removal 36h before the first p-FSH injection in all heifers. An intravaginal progesterone (P4) implant (1.38g of P4 CIDR®, Zoetis) was inserted at the time of the first p-FSH injection and removed at the time of OPU, which occurred in all heifers at 44h (Nivet et al. 2012 Reproduction 143, 165-171; https://doi.org/10.1530/REP-11-0391) after the last p-FSH injection. Additionally, follicle number was determined at OPU and classified as small (<6mm), medium (6–10mm) or large (>10mm). Oocytes from follicles of different sizes were pooled by heifer at OPU and then classified and subjected to IVP procedures. Differences between treatment groups were evaluated using generalized linear mixed models (SAS 9.4; SAS Institute Inc.) and data are presented as mean±s.e.m. (Table 1). Lengthening the FSH treatment period resulted in a greater (P=0.01) number of large follicles; however, the number of small, medium-size, and total follicles was not different between groups. Number of total recovered oocytes, viable oocytes, cleaved oocytes, as well as recovery rate, percent viable oocytes, and cleavage rate were not different (P>0.2) between groups. Similarly, the number of blastocysts produced per heifer and blastocyst rate were not different (P>0.9) among groups. In conclusion, lengthening the period of FSH treatment by 1 day increased the number of large follicles at OPU but did not improve overall ovarian response, oocyte recovery, or embryo production. Table 1. Ovarian response and IVP of heifers treated with p-FSH during 2 or 3 days before ovum pickup Response FSH2d (n=28) FSH3d (n=29) P-value Small follicles (n) 5.9±0.6 5.7±0.8 0.83 Medium follicles (n) 17.0±2.4 12.9±1.6 0.18 Large follicles (n) 2.5±0.5 4.5±0.6 0.01 Total follicles (n) 25.4±2.6 23.1±1.8 0.60 Total oocytes (n) 17.0±2.5 13.0±1.2 0.23 Recovery rate (%) 62.6±3.7 56.9±3.1 0.26 Viable oocytes (n) 14.4±2.0 11.3±1.1 0.30 Viable oocytes (%) 85.0±2.4 88.0±3.0 0.31 Cleaved oocytes (n) 8.7±1.6 7.1±1.2 0.62 Cleavage rate (%) 54.7±5.7 54.1±5.7 0.96 Blastocysts (n) 3.2±0.6 3.2±0.7 0.98 Blastocyst rate (%) 20.6±4.0 22.4±3.7 0.97


2021 ◽  
Vol 33 (2) ◽  
pp. 181
Author(s):  
C. Brochado ◽  
B. J. Duran ◽  
J. C. L. Motta ◽  
J. D. Kieffer ◽  
A. Pinczak ◽  
...  

The objective of the present study was to evaluate the effect of length of the FSH superstimulatory treatment on ovarian response and embryo production in sheep. Poll Dorset ewes (n=63) 3.2±0.2 years old weighing 58.5±1.5kg and with a body condition score of 2.7±0.1 (0=emaciated; 5=obese) were used during the transition from the breeding to the non-breeding season. All ewes received an ovarian superstimulatory treatment during the first follicular wave (Day 0 protocol). On Day −9 all ewes received a 0.3-g progesterone intravaginal device (CIDR, Zoetis) for 6 days. On Day −3, the CIDR was removed and all ewes were administered 125μg of cloprostenol sodium intramuscularly (IM) (PGF, estroPLAN, Parnell) and 200IU of equine chorionic gonadotrophin (eCG)+100IU of human chorionic gonadotrophin (hCG) IM (P.G. 600, Merck). Thirty-six hours after CIDR removal (Day −1.5) ewes were administered 100μg of gonadorelin acetate IM (gonadotrophin-releasing hormone, GnRH; Gonabreed, Parnell). Superstimulatory treatments were initiated on Day 0 (84 h after CIDR removal) with a total of 240mg of NIH-FSH-P1 (12 mL, Folltropin, Vetoquinol), and a new CIDR was used from the first to the last FSH dose (6-dose=3 days; 8-dose=4 days). Ewes were randomised to receive the total dose of FSH distributed in eight decreasing doses (8-dose group, n=33) or six decreasing doses (6-dose group, n=30) twice daily 12h apart. Two doses of PGF were administered with the last two doses of FSH, and GnRH was administered 12h after the last FSH administration. Intrauterine AI with fresh semen was performed by laparoscopy 16h after GnRH administration. Ovarian response was determined by laparoscopy 6 days after AI and ova/embryos were collected surgically in ewes with >2 corpora lutea (CL). Data were analysed using generalized linear mixed models (SAS 9.4; SAS Institute Inc.) and presented as mean±s.e.m. in Table 1. The percentage of responding donors (>2 CL) was 93.3% (28/30) and 78.8% (26/33; P=0.5) for the 6-dose and 8-dose groups, respectively. The number of CL tended (P=0.06) to be lesser in ewes in the 6-dose than the 8-dose group. However, no differences (P>0.10) were found in total ova/embryo, fertilized ova, transferable embryos, or freezable embryos. In conclusion, despite a tendency for a greater ovarian response in ewes treated with 8 doses of FSH, embryo yield did not appear to differ after either 6 or 8 doses of FSH administered during the first follicular wave in sheep. Table 1. Ovulatory response and embryo production in responding ewes (>2 corpora lutea) superstimulated with either 6 or 8 doses of FSH during the first follicular wave Outcome Treatment P-value 6-dose 8-dose Number of ewes 28 26 Corpora lutea (n) 14.2±1.7 20.3±2.8 0.06 Total ova/embryos (n) 9.0±1.3 10.9±1.8 0.38 Fertilized ova (n) 8.1±1.4 10.2±1.9 0.34 Fertilized ova (% per ewe) 89.0±5.0 81.7±7.0 0.40 Degenerate embryos 1.3±0.4 2.0±0.8 0.89 Transferable embryos (Grade 1–3) 6.8±1.2 8.2±1.8 0.52 Transferable embryos (% per ewe) 85.7±4.4 75.4±8.4 0.46 Freezable embryos (Grade 1–2) 6.6±1.1 8.2±1.8 0.43 Freezable embryos (% per ewe) 80.5±5.6 75.4±8.4 0.61


2019 ◽  
Vol 31 (1) ◽  
pp. 192
Author(s):  
R. V. Sala ◽  
L. C. Carrenho-Sala ◽  
M. Fosado ◽  
E. Peralta ◽  
D. C. Pereira ◽  
...  

The benefit of superstimulation with exogenous FSH before ovum pickup for in vitro embryo production has been the subject of significant controversy. In addition, there is limited information on different dose regimens. Thus, the objective of the present study was to evaluate the effect of dose of porcine (p)-FSH during superstimulation before ovum pickup (OPU) on in vitro embryo production in pregnant heifers. Pregnant Holstein heifers (n=36) were assigned to a complete 3×3 crossover design. Three treatment groups were evaluated as follows: p-FSH 0mg (FSH0), p-FSH 160mg (FSH160) and p-FSH 300mg (FSH300). Three sessions of OPU were performed on each animal at 48, 62 and 76 days of gestation, with a washout interval between sessions of 14 days. Follicular wave emergence was synchronized by dominant follicle removal. Heifers in the FSH0 group received no further treatment, whereas the remaining groups received a total of 4 injections 12h apart as follows: FSH160 (48.0, 42.7, 37.3 and 32.0mg) or FSH300 (90.0, 80.0, 70.0 and 60.0mg), beginning 36h after dominant follicle removal. Ovum pickup was performed in all heifers 40h after the last p-FSH injection. Heifers were subjected to OPU for oocyte recovery, and number of follicles was determined. Recovered oocytes were processed and in vitro embryo production performed. Differences between treatment groups were evaluated by generalized linear mixed models. Data are presented (Table 1) as mean±standard error of the mean. There was no effect of days in gestation for any of the outcomes evaluated (P>0.05). Follicle numbers at the time of oocyte recovery were different (P<0.01) between groups. Heifers in the FSH300 group had a greater (P<0.05) number of medium, large and total follicles than heifers in the FSH0 group, whereas heifers in the FSH160 were intermediate. Total number of recovered, viable and cleaved oocytes were greater (P<0.01) in FSH300- than in FSH160- and FSH0-treated heifers. Cleavage rate and blastocyst development rate were not different (P>0.10) between groups. The number of grade 1 and 2 blastocysts was greater in FSH300- than in FSH160- and FSH0-treated heifers (P<0.03). In summary, the use of 300mg of p-FSH before OPU in pregnant heifers increases the number of follicles, oocytes and blastocysts produced per heifer with no detrimental effect on oocyte competence. Table 1.Ovum pickup and in vitro embryo production in pregnant heifers treated with different doses of porcine FSH


2020 ◽  
Vol 32 (2) ◽  
pp. 215
Author(s):  
L. Carrenho-Sala ◽  
M. Fosado ◽  
R. Sala ◽  
E. Peralta ◽  
D. Pereira ◽  
...  

The timing of initiation of superstimulatory treatments relative to follicle wave emergence has been shown to affect ovulatory response and invivo embryo production. The significant increase of invitro embryo production (IVP) and the possibility of using pregnant animals as oocyte donors has created the need to optimise superstimulatory treatments for IVP in pregnant cattle. Thus, the objective of the present study was to evaluate the effect of synchronisation of follicle wave emergence before superstimulation for ovum pickup (OPU) and IVP in pregnant heifers. Pregnant (47-62 days of gestation) Holstein heifers (n=28) 19.5±0.3 months of age were assigned in a completely randomised design to one of two groups: synchronisation of follicular wave emergence by dominant follicle removal (DFR; all follicles >6mm) or untreated control (no DFR). Superstimulatory treatments were initiated 36h after DFR or at random stages of the follicular wave in the no-DFR group and consisted of the administration of 160mg of purified FSH (Folltropin-V, Vetoquinol) over four injections 12h apart as follows: 48.0, 42.7, 37.3, and 32.0mg. Ovum pickup was performed in all heifers 40h after the last purified FSH injection. Heifers were subjected to OPU for oocyte recovery, and the number of follicles was determined. Recovered oocytes were processed in groups by treatment, and IVP was performed. Differences between treatment groups were evaluated using generalised linear mixed models. Results are presented in Table 1 and are expressed as means±s.e.m. for data collected at the time of OPU or as proportions for embryo production results. The number of small follicles (<6mm) at the time of OPU was greater in the no-DFR group than in the DFR group (P=0.04). Conversely, there were no differences between treatments in the number of medium follicles (6-10 mm; P=0.17), large follicles (>10 mm; P=0.11), total follicles (P=0.93), total number of recovered oocytes (P=0.4), or number of viable oocytes (P=0.53). The mean oocyte percentage recovery rate was not different between heifers in the DFR (53.6±4.7%) and no-DFR (56.5±4.7%) groups (P=0.52). Both cleavage and blastocyst rate were greater (P<0.008) in the DFR group than in the no-DFR group; as a result, the number of transferable embryos per animal was 5.6 in the DFR group and 2.8 in the no-DFR group. In summary, initiation of superstimulatory treatments at the time of follicle wave emergence improves cleavage and blastocyst rates, thus leading to greater embryo production. Table 1.Ovarian response and embryo production in pregnant heifers superstimulated with or without synchronisation of follicle wave emergence Variable DFR No DFR Small follicles, n 8.1±1.2A 12.1±1.8B Medium follicles, n 18.3±1.3 13.7±2.0 Large follicles, n 2.4±0.6 1.4±0.4 Total follicles, n 28.8±1.4 27.2±2.2 Total oocytes, n 15.4±1.5 16.0±1.9 Viable oocytes, n 13.7±1.5 13.4±1.8 Cleavage rate,% (n) 77.1 (192)A 64.4 (188)B Blastocyst rate,% (n) 40.6 (192)A 20.7 (188)B A,BMeans within a row with different superscripts differ (P<0.05).


2021 ◽  
Vol 8 (2) ◽  
pp. 30
Author(s):  
Luis Emilio Fazzio ◽  
Santiago José Raggio ◽  
Juan Facundo Romero ◽  
Juver Membrebe ◽  
Antonio Humberto Hamad Minervino

A safety study on ketoprofen 10% was carried out on pigs using a different dosing and treatment scheme. Forty healthy crossbreed pigs with similar age, weight, and body condition score were distributed into five treatment groups. The pigs were intramuscularly injected once with different doses of ketoprofen: 3 mg/kg (group 1X), 6 mg/kg (group 2X), 9 mg/kg (group 3X). In addition, the 3 mg/kg dosis was administered on three consecutive days (group 1X ext.). Intramuscular injections of saline solution were used in control group (CTL). The pigs were clinically examined throughout the trial and blood samples were taken for hematological and biochemical evaluation on days −4 (before treatment), +3, +7, and +14 (the end of the trial). Any unusual behaviour or clinical signs were reported as potential toxic effects of ketoprofen. Serum measurements showed that none of the ketoprofen doses produced changes in renal or hepatic biochemical parameters, liver enzymes, or total bilirubin. Likewise, hematological assessment indicated no altered parameters or hematocrit percentage in the study groups. These results demonstrate that ketoprofen has no adverse effects in pigs when the doses and scheme evaluated in this study are applied.


1991 ◽  
Vol 52 (1) ◽  
pp. 157-163 ◽  
Author(s):  
R. G. Gunn ◽  
T. J. Maxwell ◽  
D. A. Sim ◽  
J. R. Jones ◽  
M. E. James

ABSTRACTThe effects of high-low (HL) and low-high (LH) patterns of nutrition during the 5 weeks prior to a synchronized mating were studied on the reproductive performance of 115 Welsh Mountain and 114 Brecknock Cheviot ewes in a range of body condition at the start of treatment. For 2 months prior to treatment imposition, ewes were grazed in a systematic way at different stocking rates on different sward heights to obtain a range of body condition scores. Target score groupings were 2·00 to 2·25, 2·50 to 2·75 and 3·00 to 3·25 and although scores of 1·50 to 3·25 were obtained, most lay in the 2·00 to 2·75 range. Two treatment groups, balanced for live weight and body condition score, received high and low levels of nutrition for 16 days from mid October, achieved, respectively, by a low stocking rate on a sward with a high surface height plus ad libitum concentrate and a high stocking rate on a sward with a low surface height plus 200 g hay per head per day. Treatments were then reversed for the 17 days prior to mating. Live-weight and body condition-score changes were recorded and reproductive performance at first mating was measured from counts of corpora lutea and viable embryos at slaughter either at return to service or at 4 weeks after first mating. There were no differences due to nutritional pattern in live weight or body condition score at mating. The LH treatment significantly increased the rates of ovulation, conception, multiple ova survival and potential lambing per ewe pregnant and per ewe mated in the Welsh Mountain breed but significantly increased only the rates of ovulation and potential lambing per ewe pregnant in the Brecknock Cheviot breed compared with the HL treatment. The relatively poorer response in the latter breed was partially due to a lower ovulation rate potential coupled with non-significantly lower rates of conception and survival of single-shed ova associated with the LH treatment. Much of this relatively poorer reproductive performance in the Brecknock Cheviot breed was in ewes with body condition scores 3= 2·75. Reproductive performance increased with increasing body condition at the start of treatment over the range of scores =≤ 2·25 to 2·50 in both breeds and, while continuing to improve in scores above 2·50 in the Welsh Mountain breed, in the Brecknock Cheviot breed it started to decline. Ewes with a body condition score of 2·50 in both breeds showed the greatest response in potential lambing rate to the LH treatment.


2012 ◽  
Vol 24 (1) ◽  
pp. 196
Author(s):  
M. P. Palhão ◽  
E. R. Oliveira ◽  
M. M. Gioso ◽  
B. C. Carvalho ◽  
L. G. B. Siqueira ◽  
...  

The ovarian follicular population has been used as a parameter to evaluate fertility and also the potential of donors undergoing assisted reproductive procedures in both human medicine and animal practice. There is a high correlation between follicular population and oocyte recovery by ovum pickup (OPU), but the relationship between oocyte recovery, embryo production and pregnancy rates may not be fully understood. The aim of the present study was to evaluate whether the conversion rate of oocytes to embryos and further pregnancies could be positively related to the number of cumulus–oocyte complexes (COC) recovered after OPU in cattle. For this purpose, records of 626 OPU sections from 251 nonlactating Gyr cows (dairy Zebu breed) were analysed. The animals had a good body condition score, were kept in a good feeding pasture (Brachiaria spp.) and were supplemented with corn silage and a mixture of corn, soybeans and vitamin and minerals, according to their nutritional requirements. For each ovarian aspiration, the ovarian follicular wave was previously synchronized with an auricular implant (Norgestomet-Crestar®), IM injections of 2 mg of oestradiol benzoate (Gonadiol®) and 0.25 mg of D-cloprostenol (Sincrocio®). The OPU procedures were performed using an ultrasound device (Aquila Vet, Esaote, São Paulo, Brazil) equipped with a vaginal sector 7.5-MHz probe, disposable 20 G needles and a vacuum pressure of 80 mmHg. The cows were ranked in quartiles regarding the total number of COC recovered. To reduce bias related to the eventual fluctuation of OPU results, for the present analysis the authors used only the recorded OPU session of each cow with the highest number of COC recovered. Viable COC were fertilized with sex-sorted (X) semen of Gyr bulls previously tested for in vitro embryo production. Conversion rates (%) of the total and viable oocytes to embryos, viable oocytes to pregnancy and embryo to pregnancy were evaluated for each quartile. Differences between the first and fourth quartiles were accessed by Fisher's exact test. In the 251 OPU, 4246 total and 3173 viable COC were recovered, resulting in the production of 1001 embryos (31.5%) and 453 pregnancies (45.3%). The cows ranked in the first, second, third and fourth quartiles produced >30 (41.6 ± 10.6), 21 to 30 (25.2 ± 3.0), 12 to 20 (15.9 ± 2.6) and <12 (6.7 ± 3.1) total oocytes. The average viable oocyte (29.1 ± 11.0, 18.1 ± 5.3, 11.1 ± 3.7 and 4.5 ± 2.7, respectively) and embryo production (8.6 ± 5.7, 5.2 ± 3.6, 3.8 ± 2.8 and 1.8 ± 1.8, respectively) were different (P < 0.0001) among all quartiles. Pregnancy rates, however, did not differ (46.0, 44.9, 43.9 and 45.6%, respectively; P > 0.05). Interestingly, the conversion rates (viable oocytes to embryos and viable oocytes to pregnancies) were higher (P < 0.0001 and 0.002) in cows from the last quartile (51.1 and 31.9%) compared with those from the first quartile (23.7 and 14.7%). In conclusion, the number of COC recovered by OPU (and consequently the ovarian follicular count) can further predict the total number of embryos and pregnancies produced, but it is not directly related to the oocyte development potential. Biotran and Fapemig Project CVZ APQ 01654/09 and BPD 0007/10.


2010 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
L. V. M. Gulart ◽  
L. Gabriel ◽  
L. P. Salles ◽  
G. R. Gamas ◽  
D. K. Souza ◽  
...  

FSH at low concentrations affect embryo production. In vitro culture conditions also affect embryo production and embryonic expression of genes and alter oocyte competence to produce embryos. The search for better and less variable culture conditions simulating those in vivo has led to the development of several systems of oocyte in vitro maturation culture. To compare the efficiency of the systems of MIV we utilized 4 groups: (1) TCM-199 control; (2) α-minimal essential medium (MEM); 3) α-MEM + 1 ng of FSH; 4) α-MEM+ 10 ng of FSH. The medium of Group 1 is non-defined by the presence of fetal calf serum (10%). Groups 2, 3, and 4 are defined and polyvinyl alcohol (1%) was used as a macromolecule. Porcine FSH (1 IU mg-1) was used at 1 and 10 ng mL-1 and at 100 ng in defined and non-defined medium, respectively. Bovine ovaries were collected at an abbatoir. Oocytes (n = 1718) with homogeneous cytoplasm and with more than 3 layers of granulosa cells were used. Mature oocytes from the 4 treatments (11 replicates of each treatment) were inseminated with frozen-thawed, motile sperm separated by Percoll, using Sperm TALP HEPES medium. Presumptive zygotes with up to 2 or 3 layers of cumulus cells were cultured in 50-mL drops of SOF medium, supplemented with 10% FCS and 1 mg mL-1 BSA under mineral oil in a humid 5% CO2 atmosphere at 38.5°C after. Cleavage rate was evaluated 72 h post-insemination (hpi), and blastocyst rate was evaluated 168-192 hpi. Cleavage and blastocyst rates were calculated on the basis of number of presumptive zygotes. The expression of the following genes (Bax, Bcl-2, and conexin 43) was evaluated in blastocysts by RT-PCR. One-way ANOVA was used to compare blastocyst number. There was no difference in the proportion of embryos with more than 8 blastomeres in all groups tested, indicating that the rate of development during the first 72 hpi was similar for oocytes matured in chemically defined medium and for oocytes matured in medium containing serum. Bax is a pro-apoptotic marker and Bcl-2 an antiapoptotic marker. Connexin 43 (Cx43) may be a marker of embryo competence. Glyceraldehyde 3-phosphate dehydrogenase was used as internal control. The Bax gene was not expressed in any group. The Bcl-2 and Cx43 genes were expressed, mainly in the α-MEM 10. Although no differences were observed in blastocyst rate among the groups (30% to 40%), the strong expression of Bcl-2 and of Cx43 on the group containing 10 ng mL-1 of FSH may indicate that FSH could improve embryo quality under defined conditions. The authors thank FAP-DF, CNPq, FUNPE, FINATEC, CAPES, and Biovitro Tecnologia de Embrioes Ltda, for laboratory assistance and grants, and Frigorifico Ponte Alta, Brasília-DF, for supplying bovine ovaries.


2010 ◽  
Vol 22 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Ramos ◽  
L. Cutaia ◽  
P. Chesta ◽  
G. A. Bó

Two experiments were designed to evaluate the effect of the timing of fixed-time AI (FTAI) in relation to the removal of an intravaginal progesterone-releasing device (1 g of progesterone, DIB, Syntex SA, Buenos Aires, Argentina) on pregnancy rates in Bos indicus × Bos taurus cross-bred heifers. In experiment 1, 285 Bonsmara × zebu cross-bred heifers, between 18 and 24 months of age and with a body condition score (BCS) between 3.0 and 3.5 (1-5 scale) were used. On the day of initiation of treatment (Day 0), the heifers’ ovaries were palpated (92% of them had a CL) and they received a new DIB plus 2 mg of estradiol benzoate (EB; Syntex SA) and 250 μg of cloprostenol (Ciclase DL, Syntex SA). On Day 8, DIB devices were removed and all heifers received 250 μg of Ciclase plus 0.5 mg of estradiol cypionate (ECP; Cipiosyn, Syntex SA). At that time the heifers were randomly divided to receive FTAI between 48 to 49 h, 53 to 54 h, or 58 to 59 h after DIB removal. The heifers underwent FTAI with semen from 4 bulls by 2 inseminators. In experiment 2, 260 heifers from the same group as those used in experiment 1 (87% with a CL) were treated exactly as those in experiment 1, except that previously used DIB was inserted on Day 0. Pregnancy diagnosis was performed 30 days post-fixed-time AI by ultrasonography. The data were analyzed by logistic regression, taking into account the effect of time of FTAI, semen, and inseminator on pregnancy rates. In experiment 1, pregnancy rates were lower (P = 0.04) in the heifers undergoing FTAI between 48 and 49 h after DIB removal (46/95, 48.4%) than those undergoing FTAI 53 to 54 h (61/99, 61.6%) or 58 to 60 h (57/91, 62.6%) after DIB removal. However, no differences in pregnancy rates were found (P = 0.72) in experiment 2 between the 3 treatment groups, with 39/91 (42.9%) for the 48 to 49 h group, 45/89 (50.6%) for the 53 to 54 h group, and 35/89 (43.8%) for the 58 to 59 h group. There was no effect of the semen or inseminator (P > 0.2) in either experiment. We conclude that when Bos indicus × Bos taurus beef heifers are synchronized with new DIB devices and ECP, higher pregnancy rates are obtained in heifers undergoing FTAI late (between 53 to 60 h after DIB removal) than in those undergoing FTAI early (48 to 49 h after DIB removal). However, time of insemination does not apparently affect pregnancy rates when Bos indicus × Bos taurus beef heifers are synchronized with previously used DIB devices and ECP.


2010 ◽  
Vol 22 (1) ◽  
pp. 247
Author(s):  
J. R. V. Pimentel ◽  
P. H. P. Miguez ◽  
A. Kehrle ◽  
E. H. Madureira ◽  
F. A. Braga ◽  
...  

Progestagen-releasing devices are commonly used for fixed-time artificial insemination and fixed-time embryo transfer (FTET). The aim of this study was to evaluate the efficacy of a new progesterone-releasing intravaginal device made of poly(3-hydroxy)butyrate-valerate copolymer (PHB-V) and poly-ϵ-caprolactone (PCL; Progestar®, Innovare, São Paulo, Brazil) to synchronize crossbredcows and heifers for FTET by determining ovulation, conception, and pregnancy rates. A total of 205 recipients ranging in age from 2 to 8 years (heifers, n = 77; non-suckled cows, n = 69; suckled cows, n = 59) were used on 3 different farms during February, March, and April 2008. The experimental design was a generalized block design (cyclicity, body condition score, postpartum interval, and animal category, i.e. heifers, suckled, or non-suckled cows), with 2 different synchronization treatments for FTET (Progestar® v. Crestar®). Cows were assigned to either Crestar® (norgestomet ear implants; Intervet Schering-Plough, Kenilworth, NJ, USA; n = 103) or Progestar® (PHB-V; n = 102) treatments. All groups were treated with 2 mg of estradiol benzoate i.m. (Innovare) and received the intravaginal or auricular device according to their group (Day 0). Together with P4 device withdrawal (Day 8), all animals received 400 IU of eCG i.m. (Novormon®, Schering-Plough) and 500 μg i.m. of PGF2α, (Sincrocio®, Ouro Fino, Brasil). On Day 9, all cows were treated with 1 mg of estradiol benzoate (Innovare) and the innovulation was performed on Day 17. Embryos were maintained at 37°C during the innovulation period. The percentage of usable recipients (AR) based on the presence of a functional CL on the day of embryo transfer, conception rate (numbers of pregnant recipients of the total number transferred; CR), and pregnancy rate (numbers of pregnant recipients of the total number synchronized; PR) were determined by ultrasonography 23 days after embryo transfer. Data were submitted to ANOVA (PROC GLM, SAS Institute Inc., Cary, NC, USA) and significant differences were considered to have a P-value of <0.05. None of the interactions were significant and there was no effect of treatment on AR (72.8% v. 83.3%), CR (47.9% v. 42.7%), and PR (34.7% v. 35.0%) for Progestar® v. Crestar® groups, respectively. This experiment showed that Progestar® was as efficacious as Crestar® to synchronize crossbred cows and heifers for FTET. FAPESP-Fundação de Amparo à Pesquisa do Estado de São Paulo and CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico.


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