283 INFLUENCE OF THE MOMENT OF EMBRYO TRANSFER IN PREGNANCY RATES IN FEMALE BOVINE INSEMINATED WITH IVP EMBRYOS OFTHE NELLORE BREED

2010 ◽  
Vol 22 (1) ◽  
pp. 298
Author(s):  
A. C. B. Mariani ◽  
J. F. Souza ◽  
F. B. Lopes ◽  
J. A. T. Souza ◽  
J. L. Ferreira ◽  
...  
Keyword(s):  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Fertilization In Vitro ◽  
In Vitro Production ◽  
Chi Square ◽  
Significance Level ◽  
Animal Reproduction ◽  
Chi Square Test ◽  
The Moment

The in vitro production (IVP) of bovine embryos is a biotechnique that has created new perspectives in animal reproduction and improvement. However, one of the main issues in the diffusion of this technology concerns the rate of pregnancy of the recipient cows. The objective was to verify the relationship between the fertilization in vitro, the day the recipient female was in estrus, and the pregnancy rates. Two hundred sixty crossbred recipient cows were selected from July to November 2008, synchronized with 2 different protocols at a random moment of the estrous cycle. One of the groups (G1) composed of 110 females that received 2.0 mL of D-cloprostenol, i.m. in only dose. The other group (G2), with 150 females, received a norgestomet auricular implant and 2.0 mg of estradiol benzoate i.m. On the fifth day, the females received, i.m. 200 IU of equine serum gonadotrophin and 150 μg of D-cloprostenol. The implant was removed on the eighth day, and 24 h later all animals received 1.0 mg of estradiol benzoate. The recipients entered in estrus 1 day before, 1 day after, and on the day of IVF. The embryos were transferred on Day 7 after fertilization, trancervically in the ipsilateral uterine horn that contained corpus luteum. The gestation diagnosis was made by ultrasound scan 30 days after the transfer. Data were analyzed using SAS software (version 9.0, SAS Institute, Cary, NC, USA). Initially, data were analyzed by normality test using Proc Univariate; however, a normal distribution was not observed. Data were then analyzed by PROC FREQ with nonparametric method of chi-square test and a significance level of 5%. Among the recipients, 40 were observed in estrus 1 day before IVF (D - 1), 137 on the IVF day (D0) and 83 were observed in estrus 1 day after (D + 1), resulting in a total rate of pregnancy of 38.8%. For each day the resulting pregnancy rates were 42.50% in D - 1, 41.61% in D - 0, and 30.12% in D + 1. These results suggest that there is no relationship between the day of the recipient’s estrus, the day of IVF, and pregnancy rates. There was no influence of the day of estrus in relation to the day of IVF in the gestation rates of the recipients of IVP embryos. However, more studies concerning the recipients are necessary, because they assume an important role in the success of the IVP. The authors thank Brio Genetic and Technology.

289 EFFECTS OF YEAR PERIOD, TECHNICAL TEAM, AND BREED ON THE PREGNANCY RATES AFTER TRANSFER OF IVF BOVINE EMBRYOS IN THE SOUTHERN REGION OF RIO DE JANEIRO

2010 ◽  
Vol 22 (1) ◽  
pp. 301
Author(s):  
B. G. Moura ◽  
J. Almeida ◽  
F. L. Lima ◽  
G. Balbi ◽  
R. Calmerani ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Dairy Cattle ◽  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Chi Square Test ◽  
Few Data ◽  
Rectal Palpation ◽  
Fresh Embryos

The aim of the work was to study the effects of year period, technical team, breed, beef cattle and dairy cattle on the pregnancy rates in fresh embryos used in bovine transfer of IVF programs. The study was carried out at the fertilization laboratory In Vitro Nyltta Britto de Carvalho, in partnership with In Vitro Brazil, located at the Boa Vista farm, Barra do Pirai, during August 2007 to September 2008, seeking subsidies to improve the use of the technique in the field. During that period, aspirations and inovulations in 3 different periods I (August to December), II (January to April), and III (May to September) were carried out. The jobs were accomplished by 9 technical teams (A, B, C, D, E, F, G, H, and I) rendering services to the laboratory, by working with 2 beef breeds (Brahman and Nelore) and 3 dairy breeds (Gir, Girolando, and Holstein). The different breed receivers were synchronized, and in general, from 6 to 8 days after heat, they received embryo transfer, the cervical way, under low epidural anesthesia, where each female received 1 fresh embryo of IVF. All cows were submitted to gestation diagnosis by rectal palpation and ultrasonography, in general, 42 days after embryo transfer. The numbers of embryo transferred and pregnancy rates were submitted to the chi-square test, which presented significant differences (P < 0.05). There were pregnancy rates of 36.25%a (n = 960), 39.83%a (n = 1180), and 32.59%b (n = 919) in the I, II, and III periods, respectively. Among the 9 technical teams, there were verified pregnancy rates (%) of 33.51d (n = 1313), 30.30d (n = 330), 35.00cd (n = 405), 39.24cd (n = 1060), 59.25a (n = 7), 33.33d (n = 24), 53.57bc (n = 28), 43.31c (n = 157), and 58.33ab (n = 12) for A, B, C, D, E, F, G, H, and I teams, respectively. Among breeds there were rates (%) of 36.89ab (n = 412), 34.68b (n = 1286), 35.13ab (n = 74), 38.94a (n = 1140), and 37.80ab (n = 82) for Brahman, Nelore, Gir, Girolando, and Holstein, respectively. In the study, pregnancy rates (%) of 35.21b (n = 1698) in beef cattle and 38.65a (n = 1296) in dairy cattle were observed. The differences in pregnancy rates with respect to the evaluated factors, may be explained by individual, breed, and nutritional variations of the animals. There are few data in the literature with results on the embryo transfer use of IVF bovine under field conditions.

scholarly journals Prostaglandin F2? as ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome

2021 ◽  
Vol 42 (1) ◽  
pp. 193-208
Author(s):  
Luiz Francisco Pfeifer ◽  
◽  
Natália Castro ◽  
Jamyle Pereira ◽  
Augusto Schneider ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Single Point ◽  
Estradiol Benzoate ◽  
Preovulatory Follicle ◽  
Chi Square ◽  
Lactating Dairy Cows ◽  
Chi Square Test ◽  
The Moment ◽  
Dichotomous Outcomes ◽  
To Receive

This study evaluated the effect of a prostaglandin F2? (PGF) analogue as an ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome. To this end, three experiments were performed in the state of Rondônia, located in the Amazon biome. In Experiment 1, 22 lactating dairy buffaloes received 2 mg of intramuscular (I.M.) estradiol benzoate (EB) on day 0 and an intravaginal progesterone-releasing device (CIDR) from day 0 to day 9 of the protocol. On days 8 and 9, all cows were given 500 ?g of I.M. d-cloprostenol (PGF analogue). On day 10, buffaloes were divided into two groups to receive 500 ?g of PGF (PGF group, n = 8) or no treatment (CTL group, n = 14), respectively. In Experiment 2, 16 lactating crossbred dairy cows (Holstein x Gir) received 2 mg of EB on day 0 and a CIDR insert from day 0 to day 8. On days 7 and 8, all cows were given 500 ?g of d-cloprostenol. On day 9, cows were divided into two groups to receive 500 ?g of d-cloprostenol (PGF group, n = 8) or no treatment (CTL group, n = 8), respectively. In Experiment 3, 16 lactating crossbred dairy cows (Holstein x Gir) were handled and treated similarly as in Experiment 2, although cows did not receive d-cloprostenol on day 8. Single-point outcome variables were analyzed using one-way analysis of variance (ANOVA), while proportions with dichotomous outcomes were analyzed with the chi-square test. In Experiment 1, there was no difference (P = 0.30) in the ovulation rate between groups, and, on average, 68% of the buffaloes ovulated. Moreover, the treatment did not affect the interval to ovulation (P = 0.61) nor the diameter of the preovulatory follicle (P = 0.47). As for Experiment 2, only one cow, from the PG group, did not ovulate. There were no differences between the CTL and PG groups (P = 0.69) in the moment of ovulation, which occurred in average 82 h after CIDR removal. Finally, in Experiment 3, cows treated with PGF ovulated earlier than those in the CTL group (62.5 ± 5.8 and 94.5 ± 13.5 h, respectively; P = 0.05). Collectively, these results suggest that PGF hastens ovulation in lactating dairy cows, whereas no effect was observed in dairy buffaloes.

188 EFFECT OF TRANSFER OF FROZEN-THAWED IVF EMBRYOS ON PREGNANCY IN REPEAT-BREEDER INSEMINATED OR NON-INSEMINATED HOLSTEIN CATTLE

2006 ◽  
Vol 18 (2) ◽  
pp. 202 ◽  
Author(s):  
O. Dochi ◽  
M. Tanisawa ◽  
S. Goda ◽  
H. Koyama
Keyword(s):  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Calf Serum ◽  
Pregnancy Rates ◽  
Holstein Cattle ◽  
Chi Square ◽  
Vitro Fertilization ◽  
Chi Square Test ◽  
Repeat Breeder

Repeat-breeding is one of the important factors that affect dairy management. The objective of this study was to investigate the effect of transfer of frozen–thawed IVF embryos on pregnancy in repeat-breeder Holstein cattle. Cumulus–oocyte complexes (COCs) were collected by aspiration of 2–1-mm follicles from ovaries obtained at a local abattoir. COCs were matured for 20 h in TCM-199 supplemented with 5% calf serum (CS) and 0.02 mg/mL of FSH at 38.5°C under a 5% CO2 atmosphere in air. Matured oocytes were inseminated with spermatozoa of 5 × 106/mL in BO solution (Brackett and Oliphant 1975 Biol. Reprod. 12, 260–274) containing 10 mM hypotaurine and 4 units/mL heparin. After 18 h of gamete co-culture, presumptive zygotes were cultured in CR1aa (Rosenkrans et al. 1991 Theriogenology 35, 266) supplemented with 5% CS for 8 days at 38.5°C under 5% CO2, 5% O2, 90% N2 atmosphere in air. After in vitro fertilization, Day 7 and Day 8 blastocysts were frozen in 1.5 M ethylene glycol (EG) in Dulbecco's PBS (DPBS) supplemented with 0.1 M sucrose and 20% CS. Embryos were transferred into a freezing medium, loaded into 0.25-mL straws, and allowed to stand for 15–20 min for equilibration. The straws were then plunged into a −7°C methanol bath of a programmable freezer for 1 min, seeded at −7°C, maintained at −7°C for 15 min, cooled to −30°C at the rate of −0.3°C/min, and then plunged into liquid nitrogen. Recipient animals (43 heifers, 131 cows) included those that did not conceive after being artificially inseminated (AI) 3 to 15 times. The frozen–thawed IVF embryos were directly transferred to the recipient animals 7 days after estrus or AI. Pregnancy rates were analyzed by chi-square test. The results are presented in Table 1. There were no significant differences in the pregnancy rates between treatments. However, a slightly higher pregnancy rate was achieved by embryo transfer after AI. These results suggest that embryo transfer may increase the pregnancy rate in repeat-breeder Holstein cattle. Table 1. Pregnancy rates after transfer of IVF frozen–thawed embryos in repeat-breeder Holstein cattle

241 EFFECT OF PRODUCTION EFFICIENCY IN THE LIKELIHOOD OF PREGNANCY OF IN VITRO-DERIVED BOVINE EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 210
Author(s):  
L. F. Feres ◽  
L. S. A. Camargo ◽  
M. P. Palhao ◽  
F. Z. Brandao ◽  
J. H. M. Viana
Keyword(s):  
Pregnancy Rate ◽  
Production Efficiency ◽  
Production Systems ◽  
Bos Indicus ◽  
Pregnancy Rates ◽  
In Vitro Production ◽  
Cleavage Rate ◽  
Embryo Production ◽  
Chi Square

Improving in vitro culture systems to optimize embryo yield has been a major research goal. The relationship between the efficiency of embryo production systems and the pregnancy outcomes, however, remain controversial. The aim of the present study was to evaluate the likelihood of pregnancy of in vitro-produced embryos derived from batches with different relative efficiency indexes. Data of 702 ovum pick-up (OPU) and in vitro embryo production (IVEP) sessions, and of 2456 embryo transfers, recorded from 2008 to 2012, were evaluated. All donors were from the same herd, and were of the same breed (Gir, Bos indicus), as well as the semen used for IVF. The cumulus-oocycte complex (COC) recovery and IVEP were performed by the same team, in a single IVF laboratory, and using standard medium and procedures. Only data from embryos transferred as fresh were used, and records from 97 OPU/IVEP sessions in which no embryo was produced, or embryos were frozen or discharged due to lack of recipients, were discharged. The remaining 605 sessions were stratified in quartiles (I to IV, each one corresponding to 25% of total data) according to COC production of the donors, or stratified in ranges (0–25%, 26–50%, 51–75%, and 76–100%) according to COC quality (percentage of viable COC or of grade I COC) and to embryo production efficiency endpoints (cleavage rate, blastocyst rate). Pregnancy rates were compared among quartiles or ranges by the chi-square method. On average, the Gir donors produced 24.8 ± 0.6 COC per OPU, from which 14.4 ± 0.4 were classified as viable (57.8%), and 3.2 ± 0.1 as grade I (12.9%). On average 6.1 ± 0.2 embryos (morulas and blastocysts) were produced per OPU per donor, and mean pregnancy rate was 30.9%. As expected, donors with greater total COC yield (quartile I) also produced more viable oocytes (25.5 ± 0.7 v. 15.7 ± 0.3, 10.5 ± 0.2 and 5.8 ± 0.2), more COC grade I (4.8 ± 0.4 v. 3.9 ± 0.3, 2.6 ± 0.2 and 1.6 ± 0.1), and more embryos (9.0 ± 0.4 v. 6.9 ± 0.3, 5.0 ± 0.2 and 3.3 ± 0.1) than donors from quartiles II, III, or IV, respectively (P < 0.0001). Nevertheless, there was no difference (P > 0.05) in pregnancy rates for embryos produced from donors ranked in the different quartiles (30.9 v. 29.3, 31.5, and 30.5% for quartiles I to IV, respectively). Similarly, there was no difference (P > 0.05) in the pregnancy rate of embryos derived from OPU sessions in which there was a high or low percentage of viable or grade I COC. In vitro production efficiency (cleavage and blastocyst rates) also had no effect (P > 0.05) on further pregnancy rates. In conclusion, these results suggest that there is no relationship among the average number or quality of the COC recovered by OPU, the efficiency of IVEP, and the likelihood of pregnancy of in vitro-derived embryos.Research was supported by Fazendas do Basa, CNPq, and Fapemig.

363 FACTORS INFLUENCING PREGNANCY RATES FOLLOWING TRANSFER OF BOVINE IN VIVO EMBRYOS BIOPSIED FOR SEX DETERMINATION

2007 ◽  
Vol 19 (1) ◽  
pp. 297
Author(s):  
S. Li ◽  
W. Yu ◽  
J. Fu ◽  
Y. Bai ◽  
F. Jin ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Embryo Survival ◽  
Chi Square Test ◽  
First Time ◽  
Fresh Embryos

Data collected from commercial embryo transfer programs in 63 farms in China during June 2002 to December 2005 was analyzed to examine the effects of various factors (biopsy, freezing, sample size, embryo development and quality, in vitro culture, and recipient quality) on pregnancy rates of in vivo-biopsied embryos. Embryos were flushed from superovulated dairy cattle and subjected to a biopsy for sexing determination using protocols and sexing kits supplied by AB Technology Ltd. Fresh embryos were implanted on the same day or frozen with AG freeze medium (AB Technology Ltd., Pullman, WA, USA) for later transfer. Recipients were synchronized with CIDA + PG protocols. Embryos were cultured in 6-well dishes containing 1.3 mL of holding medium (AB Technology Ltd.) in each well at room temperature (20–25�C) for examination of embryo survival in vitro. The chi-square test was used in statistic analysis. The implantation of fresh embryos after biopsy did not affect pregnancy rates (49.6%, 257/518) compared to that of non-biopsied fresh and frozen–thawed embryo groups (52.9%, 47/140 and 46.6%, 177/380, respectively). However, for biopsied embryos subjected to frozen and thawed procedures before implantation, particularly for those subjected to the removal of a larger biopsy, a reduced pregnancy rate was observed (41.8%, 297/710; P &lt; 0.01). Pregnancy rates among biopsied embryos at 3 different development stages (morula-early blastocyst, blastocyst, and expanded blastocyst) were not different. Similar results were found between embryo groups of grade 1 and 2. A significant decrease in pregnancy rate (0/10) was observed with embryos held in vitro for a longer period of time (&gt;5 h), suggesting detrimental effects of in vitro conditions on embryo survival. The highest pregnancy rate (68.0%) was observed in recipients synchronized for the first time before being implanted with biopsied embryos. Significant decreases in such rates were found in recipients synchronized for the second or third times or those with an abortion history at the first or second synchronization-implantation treatment (P &lt; 0.01). Better pregnancy rates (45.6%, 41/90; 46.1%, 76/165; and 45.5%, 5/11) were obtained for recipients implanted with biopsied embryos at Days 7.5, 8.0, and 8.5 post-heat detection, respectively, compared to 16% at Day 7 (3/18, P &lt; 0.05). It is concluded that mechanical treatment (cutting) does not reduce the survival of biopsied embryos; however, cryopreservation reduces their ability to survive in vivo. The analyses also suggest that holding embryos in vitro should not be longer than 5 h unless more favorable in vitro conditions can be provided. To achieve better results of implantation of biopsied embryos, embryo transfer should be performed during 7.5–8.5 days post-estrus, and the healthy recipients synchronized for the first time should be used.

24 EVALUATION OF THE PREGNANCY RATE OF FIXED-TIME ARTIFICIALLY INSEMINATED BOS INDICUS COWS USING HETEROSPERMIC AND MONOSPERMIC SEMEN

2013 ◽  
Vol 25 (1) ◽  
pp. 159
Author(s):  
J. P. Detomini ◽  
R. R. Tirloni ◽  
C. V. Araujo ◽  
L. R. Martins
Keyword(s):  
Pregnancy Rate ◽  
Estrous Cycle ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Mato Grosso ◽  
Chi Square Test

The aim of this study was to establish a comparison between heterospermic and monospermic semen on the pregnancy rate of fixed-time AI Bos indicus cows. The experiment was conducted in the state of Mato Grosso, Brazil, during December 2010 and February 2011. Multiparous (n = 173) and primiparous (n = 204) Nelore cows, 45 ± 15 days postpartum, were evaluated on body condition score (BCS; score 1 to 9), and those that presented BCS between 5 and 8 were selected. Two protocols of estrous cycle synchronization were performed (PeCG and Pshang). Synchronization of the estrous cycle was achieved with the aid of the following protocol: on Day 0, all animals were treated with a progesterone vaginal implant with 1.9 g of progesterone combined with an IM injection of 2 mg of estradiol benzoate. On Day 7, an IM injection of 12.5 mg of dinoprost was administered. On Day 9, implants were withdrawn and the animals received an IM injection of 0.5 mg of estradiol cypionate. On Day 9, part of the animals (n = 222) received an IM injection of 300 IU mg of eCG (PeCG) and the other part (n = 155) had their calves removed for 48 hours (Pshang). All animals were inseminated 46 to 52 h after the end of the protocol. Cows were allocated randomly in 4 groups according to the donor male sample in the semen straw and groups were designated as MA (monospermic straw from bull A; n = 110), MB (monospermic straw from bull B; n = 102), MC (monospermic straw from bull C; n = 108), and HT (heterospermic sample from bulls A, B, and C; n = 57). Commercially available semen straws from Aberdeen Angus donors were used (ABS Pecplan, Brazil). Pregnancy diagnosis was performed 35 days after AI using real-time ultrasonography. Results are summarized in Table 1. There was no statistical difference between MA, MB, MC, and HT in any group according to the chi-square test (P > 0.05). However, there was a remarkable difference in pregnancy rates among the 3 bulls tested considering both protocols, probably due to the variation in the ovulation moment. Table 1.Pregnancy rates of Nelore cows submitted to FTAI protocol inseminated with monospermic (bull A, B, or C) or heterospermic (HT) semen

288 KINETICS OF FERTILIZATION, DEVELOPMENT, AND SEX RATIO OF IN VITRO-PRODUCED BOVINE EMBRYOS OBTAINED WITH FOUR DIFFERENT BULLS

2007 ◽  
Vol 19 (1) ◽  
pp. 259 ◽  
Author(s):  
M. Alomar ◽  
H. Tasiaux ◽  
S. Remacle ◽  
F. George ◽  
D. Paul ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Time Lapse ◽  
Blastocyst Stage ◽  
Bovine Embryos ◽  
In Vitro Production ◽  
Chi Square ◽  
Cell Stage ◽  
Chi Square Test ◽  
Kinetics Of

The between-bulls variation in in vitro fertility and the shift of sex ratio toward male embryos are two problems affecting the in vitro production (IVP) of bovine embryos. Our objective was to evaluate the possible correlation between the kinetics of fertilization, embryo development, and the sex ratio of the resulting embryos. In a first experiment, and using frozen-thawed semen of 4 different AI bulls, the kinetics of pronucleus (PN) formation was evaluated at 8, 12, and 18 h post-in vitro insemination (hpi) after fixation and staining with Hoechst 33342. Fertilized oocytes were classified in 3 PN stages: PN1: showing the first signs of sperm head decondensation; PN2: with two pronuclei of different sizes, the two being far from each other; and PN3: showing two symmetric pronuclei of equal size, close to each other. Differences between bulls were observed at each time point, but were greater at 12 hpi than at 8 or 18 hpi. At 8 hpi and 12 hpi, bull C showed a significantly faster PN formation by comparison with the 3 other bulls (chi-square test: P &lt; 0.05), whereas at 18 hpi, the proportion at each of the PN stages was similar to that of bulls A and D, with bull B showing delayed PN development. In a second experiment, a standard IVP procedure was conducted with the 4 bulls to determine cleavage and blastocyst rates. The timing of first cleavage was measured using time-lapse cinematography. Compared with those of bull B, the embryos generated with bull C led to significantly higher Day 7 blastocyst yields (31.3 � 9.5% vs. 21.9 � 6.7%; ANOVA: P &lt; 0.05). Moreover, the embryos from bull C reaching the blastocyst stage cleaved faster (first cleavage at 23.1 � 2.1 hpi vs. 25.4 � 2.7 hpi for bull B; ANOVA: P &lt; 0.05). In a third experiment, 65 to 76 Day 8 blastocysts were sexed per bull. Embryo sexing was performed by PCR using the co-amplification of a Y-specific bovine SRY sequence and an autosomal btRep-137 sequence. Only blastocysts obtained with bull C showed a shift in sex ratio toward male embryos (76.0% male embryos vs. 53.8% for bull B; chi-square test: P &lt; 0.05), whatever the size of the blastocyst. The shift in sex ratio was already present at the 2-cell stage (64.2% male embryos; n = 53; chi-square test: P &lt; 0.05). In conclusion, for 2 out of 4 bulls, a correlation was observed between the kinetics of PN formation, the timing of first cleavage, and the sex ratio of the resulting embryos.

12 THE EFFECT OF PROGESTERONE CONTENT IN A VAGINAL INSERT ON PREGNANCY RATES IN BEEF AND DAIRY CATTLE INSEMINATED AT FIXED TIME

2006 ◽  
Vol 18 (2) ◽  
pp. 114
Author(s):  
L. Cutaia ◽  
M. Aviles ◽  
F. Feresin ◽  
A. Franzoni ◽  
L. Peres ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Body Condition Score ◽  
Fixed Time ◽  
Beef Cows ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Holstein Cows ◽  
Chi Square ◽  
Condition Score ◽  
Chi Square Test

Three experiments were conducted to compare pregnancy rates in cows and heifers treated with intravaginal progesterone (P4)-releasing devices impregnated with either 0.5 or 1.0 g of P4 and inseminated at a fixed time (FTAI). In Experiment 1, 102 postpartum beef cows (Hereford and Angus crossbred with Tuli, 60 to 90 d postpartum) with a body condition score (BCS) of 2.5 to 3.0 (1 to 5 scale) were used. On Day 0, all cows received 2 mg of estradiol benzoate (EB; Syntex, Argentina) i.m. and were randomly assigned to receive an intravaginal progesterone-releasing device with 0.5 g of P4 (DIB 0.5 g; Syntex) or 1.0 g of P4 (DIB 1.0 g; Syntex). On Day 7, DIB devices were removed and all cows received 150 µg D(+)cloprostenol (Ciclase; Syntex) i.m. On Day 8, all cows received 1 mg EB and were FTAI 52 to 56 h after DIB removal. In Experiment 2, 93 Holstein cows that were 90 to 110 days in milk (DIM), producing on average 5000 kg of milk per lactation and with a BCS of 2.5 to 3.0 received the same treatments as those in Experiment 1. In Experiment 3, 100 Holstein heifers, 20 to 22 months old, with a BCS of 2.5 to 3.0, also received the same treatments as those in Experiment 1. Pregnancy rates in all experiments were determined by ultrasonography 35 days after FTAI and compared by chi-square test. No differences in pregnancy rates were detected between lactating beef cows, dairy cows, or dairy heifers treated with DIB devices impregnated with 0.5 or 1.0 g of P4 (Table 1). It was concluded that vaginal P4 releasing devices impregnated with 0.5 g or 1.0 g of P4 results in comparable pregnancy rates in FTAI protocols in beef and dairy cattle. Table 1. Pregnancy rates in postpartum beef cows, Holstein cows, and Holstein heifers treated with DIB devices impregnated with 0.5 or 1.0 g of P4 and subjected to FTAI

16 OVULATION AND PREGNANCY RATES IN POSTPARTUM BOS INDICUS COWS TREATED WITH PROGESTERONE VAGINAL DEVICES AND ESTRADIOL BENZOATE, WITH OR WITHOUT eCG AND TEMPORARY WEANING

2006 ◽  
Vol 18 (2) ◽  
pp. 116 ◽  
Author(s):  
D. Maraña ◽  
L. Cutaia ◽  
L. Peres ◽  
D. Pincinato ◽  
L. F. K. Borges ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Corpora Lutea ◽  
Chi Square ◽  
Ovulatory Follicle ◽  
Chi Square Test

Two experiments were designed to compare the effects of eCG treatment and temporary weaning on ovulation and pregnancy rates in postpartum cows. In Experiment 1, 39 lactating multiparous crossbred Bos indicus cows, 60 to 80 d postpartum with a body condition score (BCS) between 2.0 to 2.5 out of 5 were randomly allocated to one of four treatment groups in a 2 � 2 factorial design. On Day 0, all cows received a progesterone (P4) intravaginal device (DIB; Syntex, Argentina) and 2 mg estradiol benzoate (EB) i.m. (Syntex). On Day 8, DIB devices were removed and all cows received 150 �g D(+)cloprostenol i.m. (Ciclase; Syntex) and were randomly divided to receive 400 IU eCG i.m. (Novormon 5000; Syntex) at the same time or no treatment. In addition, half of the cows in each group had their calves weaned temporarily (TW) for 56 h at the time of DIB removal; the other half remained with their calves. All cows received 1 mg EB i.m. on Day 9 and were examined every 8 h by ultrasonography from the time of DIB removal until ovulation. Data were analyzed by ANOVA and chi-square test. The diameter of the dominant follicle on Day 8 (eCG: 7.8 � 0.5 mm vs. no eCG: 8.2 � 0.4 mm, and TW: 7.6 � 0.4 mm vs. no TW 8.4 � 0.5 mm), the proportion of cows that ovulated (eCG: 12/20, 60% vs. no eCG: 9/19, 47%; and TW: 13/20, 65% vs. no TW: 8/19, 42%, and the interval to ovulation (eCG: 72.0 � 1.4 h vs. no eCG: 75.6 � 2.0 h, and TW: 73.8 � 1.6 h vs. no TW: 73.0 � 1.8 h) did not differ among groups (P > 0.05). Although there was no effect of eCG treatment or eCG by TW interaction (P > 0.3) on the size of the preovulatory follicle (eCG: 11.1 � 0.4 mm vs. no eCG: 10.1 � 0.6 mm), it was smaller in cows TW (9.9 � 04 mm), compared to those not TW (11.8 � 0.3 mm; P < 0.05). Nevertheless, the growth rate of the ovulatory follicle was greater (P < 0.02) in cows treated with eCG (1.1 � 0.1 mm/day) than in those not treated with eCG (0.6 � 0.1 mm/day). In Experiment 2 769 lactating multiparous crossbred Bos indicus cows received the same treatments as those in Experiment 1 and were fixed-time inseminated (FTAI) 52 to 56 h after DIB removal. Cows were examined by ultrasonography on Day 0 (22.5% with corpora lutea (CL), 30.0% with follicles >8 mm, and 47.5% with follicles <8 mm) and 42 d after FTAI to determine pregnancy. Data were analyzed by logistic regression. Pregnancy rates were not affected (P > 0.7) by TW (TW: 141/397, 37.2% vs. no TW: 141/390, 36.1%) or the TW by eCG interaction (P > 0.7). However, pregnancy rates were higher (P < 0.05) in cows treated with eCG (154/377, 40.8%) than in those not treated with eCG (128/392, 32.6%). The use of eCG but not TW improved pregnancy rates following FTAI in postpartum Bos indicus cows. Results also suggest that the eCG-related increase in pregnancy rates may be due to the final growth rate of the ovulatory follicle.

74 EFFECT OF BETA-MERCAPTOETHANOL ON THE VITRIFICATION CRYOTOLERANCE OF BOVINE IN VITRO-PRODUCED EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 137
Author(s):  
E. S. Ribeiro ◽  
M. C. Gonçalves ◽  
M. C. Pedrotti ◽  
L. T. Martins ◽  
R. P. C. Gerger ◽  
...  
Keyword(s):  
Cell Number ◽  
Blastocyst Stage ◽  
High Humidity ◽  
In Vitro Production ◽  
Chi Square ◽  
Embryo Survival ◽  
Chi Square Test ◽  
Vitro Production ◽  
Hatching Rates

The control of oxidative processes in in vitro production (IVP) systems by the use of additives may be an alternative approach to improve embryo cryotolerance. The aim of this study was to verify the effect of β-mercaptoethanol (βME) on the cryotolerance of bovine IVP embryos. In 7 replications, and following IVM-IVF, presumptive zygotes (n = 3735) were in vitro-cultured in SOF medium supplemented or not with 100 μm βME (IVC treatment), at 38.5°C and high humidity. The initial 24 h of IVC was performed in 5% CO2 in air, with the remaining 6 days of IVC carried out in 5% CO2, 5% O2, and 90% N2. On Day 7, resulting blastocysts and expanded blastocysts were vitrified in glass micropipettes in a solution with 20% ethylene glycol + 20% propylene glycol. After warming, embryos were randomly allocated to 1 of 2 sub-groups for an additional 72 h of IVC to the hatching blastocyst (HBL) stage, in fresh SOF medium supplemented or not with 100 μm βME (PVC treatment), at 38.5°C, high humidity and 5% CO2. Experimental groups were as follows: G1 (βME-free medium during IVC and PVC); G2 (βME only during PVC); G3 (βME only during IVC); and G4 (βME during IVC and PVC). Cleavage (Day 2) and blastocyst (Day 7) rates in the IVC treatment and hatching rates (Days 7 to 9) for the PVC treatment were analyzed by the chi-square test, for P < 0.05. Total cell number (TCN) estimated by fluorescence staining in HBL derived from vitrified and nonvitrified embryos was analyzed by ANOVA. The use of βME during IVC did not affect cleavage rates (βME-free, 1491/1858, 80.2% v. βME, 1522/1877, 81.1%), but negatively affected development to the blastocyst stage (βME-free, 813/1858, 43.8% v. βME, 525/1877, 28.0%). Following vitrification, however, βME supplementation during PVC improved hatching rates (G2, 58.1% and G4, 63.8%) compared with groups without the additive (G1, 36.6% and G3, 42.0%). In addition, the presence of βME either during IVC or PVC, or during both culture periods, increased TCN in HBL from vitrified embryos (Table 1). The use of βME during IVC, irrespective of the presence of βME during the PCV period, caused an increase in TCN in HBL in G3 + G4, with no effects on hatching rates (Table 1b), whereas the addition of βME during PVC, irrespective of the presence of βME during the IVC period, resulted in greater hatching rates and TCN in HBL in G2 + G4 than in G1 + G3 (Table 1). In conclusion, the addition of βME during the IVC period did not affect cleavage, but reduced blastocyst yield. Despite that, βME supplementation during the IVC period appeared to have increased the cryotolerance of the resulting blastocysts, expressed by greater TCN in HBL, whereas βME supplementation during the PVC period also improved embryo survival to the vitrification process, manifested by greater hatching rates and TCN in HBL. Table 1.Effect of βME on the cryotolerance of bovine IVP embryos This study was supported by a grant from CNPq/Brazil.

Sign in / Sign up

Export Citation Format

Share Document