97 IN VIVO AND IN VITRO EMBRYO PRODUCTION WITH Y-SEXED SORTED OR CONVENTIONAL SEMEN IN BEEF CATTLE

2014 ◽  
Vol 26 (1) ◽  
pp. 162
Author(s):  
H. Tribulo ◽  
J. Carcedo ◽  
R. Tribulo ◽  
J. Menajovsky ◽  
B. Bernal ◽  
...  
Keyword(s):  
Animal Health ◽  
T Test ◽  
High Fertility ◽  
In Vitro Production ◽  
Embryo Production ◽  
Sexed Semen ◽  
Chi Squared ◽  
In Vitro Embryo Production

An experiment was designed to evaluate in vivo and in vitro embryo production following the use of frozen–thawed conventional or Y-sexed semen from a Brangus bull with known high fertility. For in vivo embryo production, Brangus heifers (n = 12) were superovulated twice in a crossover design and inseminated with sexed or conventional semen. On Day 0, all heifers received an intravaginal progesterone device (DIB 1 g, Syntex S.A., Buenos Aires, Argentina) and 2.5 mg oestradiol benzoate and 50 mg progesterone (Progestar, Syntex S.A.) by intramuscular injection (IM). On Day 4, heifers were superstimulated with 200 mg of NIH-FSH-P1 Folltropin-V (Bioniche Animal Health, Belleville, Ontario, Canada) in twice-daily decreasing doses over 4 days. In the a.m. and p.m. of Day 6, all heifers received PGF2a (Ciclase, Syntex) and DIBs were removed in the p.m.. In the a.m. of Day 8, heifers received 100 μg de Gonadolerin (Gonasyn, Syntex S.A.) and were randomly allocated to receive either one straw of conventional semen (24 × 106 sperm per dose) 12 and 24 h later or two straws of sexed semen (2.4 × 106 sperm per dose) 18 and 24 h after GnRH. Ova/embryos were collected nonsurgically on Day 15 and evaluated following IETS recommendations. Means were compared by t-test. Mean ( ± s.e.m.) number of ova/embryos, fertilized ova, and transferable embryos were 14.8 ± 2.7, 9.4 ± 1.8, and 7.1 ± 1.7 v. 16.8 ± 3.1, 9.9 ± 2.5, and 8.1 ± 2.0 for donors inseminated with conventional or sexed semen, respectively (P > 0.6). For in vitro production, oocytes were obtained from 50 ultrasound-guided follicle aspiration (OPU) sessions that was performed at random stages of the oestrous cycle and without superstimulation in 22 Brangus cows and heifers. Oocytes were classified and matured in TCM-199 medium with NaHCO3 and supplemented with 1% fetal bovine serum. Semen samples from the same bull used for in vivo embryo production were selected using Percoll and capacitated in Fert medium and used at a final concentration of sperm/mL for nonsexed semen and 2 × 106 sperm mL–1 for sexed semen. After 16 h (sexed) or 18 h (conventional) in Fert medium, zygotes were denuded and cultured in SOF supplemented with 0.4% BSA under oil at 37°C, 5% CO2 and saturated humidity for 7 days. The total number of oocytes matured and fertilized was 528 and 318 for conventional and sexed semen, respectively. Means were compared by t-test and proportions by chi-squared test. Mean (± s.e.m.) number of cleaved zygotes and blastocysts produced per OPU session did not differ between conventional (11.0 ± 1.4 and 7.1 ± 1.0) and sexed (8.7 ± 0.8 and 4.9 ± 0.7; P > 0.2) semen. However, the proportion of cleaved zygotes and blastocysts produced were significantly higher (P < 0.05) with conventional semen (61.2%; 329/538 and 39.4%; 212/538) than with sexed semen (54.4%; 173/318 and 30.8%; 98/318), respectively. In conclusion, comparable number of embryos can be obtained in vivo with sexed or conventional semen from a bull with proven high fertility. However, the proportion of blastocysts produced in vitro is likely to be reduced following the use of sexed as compared with conventional semen from the same bull.

244 IN VITRO EMBRYO PRODUCTION WITH CONVENTIONAL OR Y-SEXED SEMEN IN BEEF CATTLE

2015 ◽  
Vol 27 (1) ◽  
pp. 211 ◽  
Author(s):  
H. E. Tribulo ◽  
J. Carcedo ◽  
R. J. Tribulo ◽  
B. Bernal ◽  
J. Garzon ◽  
...  
Keyword(s):  
Mixed Models ◽  
Random Variable ◽  
In Vitro Production ◽  
Cleavage Rate ◽  
Embryo Production ◽  
Sexed Semen ◽  
The Mean ◽  
In Vitro Embryo Production ◽  
Follicle Aspiration

An experiment was designed to evaluate in vitro embryo production following the use of frozen-thawed conventional or Y-sexed semen from a single Brangus and a single Braford bull of proven fertility. Semen was obtained by splitting the same ejaculate to be frozen directly or sex-sorted and then frozen. Oocytes were obtained from 69 ultrasound-guided follicle aspiration (ovum pickup) sessions performed at random stages of the oestrous cycle without superstimulation in 24 Brangus and 10 Braford cows and heifers. Viable oocytes (n = 1120) were matured in TCM-199 medium with NaHCO3 and supplemented with 1% fetal bovine serum. Frozen-thawed sperm from the Brangus and Braford bulls were selected with Percoll for IVF, capacitated in Fert Medium, and used at a final concentration of sperm per milliliter for conventional (non-sexed) semen and 2 × 106 sperm mL–1 for Y-sexed semen. After 16 h (sexed) or 18 h (conventional) of co-incubation with oocytes in Fert Medium, presumptive zygotes were denuded and cultured in SOF supplemented with 0.4% BSA under oil at 37°C, 5% CO2, and saturated humidity for 7 days. The total number of oocytes matured and fertilized from the Brangus donors was 538 and 318 for conventional and sexed semen, respectively. The total numbers of oocytes matured and fertilized from the Braford donors were 139 and 125 for conventional and sexed semen, respectively. Data were compared by ANOVA for mixed models, using breed and type of semen as fixed variables and cow (i.d.) as a random variable. Cleavage and blastocyst rates were first transformed by square root and then analysed by ANOVA for mixed models. Mean (± s.e.m.) number of total viable oocytes collected, cleaved zygotes, and blastocysts produced per ovum pickup session did not differ (P = 0.18) between breeds (Brangus: 17.1 ± 1.6, 10.0 ± 0.9, and 6.2 ± 0.7 v. Braford: 13.9 ± 2.8, 7.6 ± 1.5, and 4.0 ± 0.8), and there was no breed × semen interaction on the mean number of cleaved zygotes and blastocysts produced. However, the mean (± s.e.m.) number of cleaved zygotes and blastocysts produced was significantly higher (P < 0.05) when the oocytes were fertilized with conventional semen (10.7 ± 1.2 and 6.5 ± 0.8) than with sexed semen (7.7 ± 0.7 and 4.3 ± 0.6). The mean cleavage rate was also significantly higher (P < 0.05) when the oocytes were fertilized with conventional semen (76.8 ± 3.9) than with sexed semen (54.1 ± 4.2). Blastocyst rate tended to be higher (P = 0.1) with conventional semen (40.5 ± 3.3) than with sexed semen (33.6 ± 4.2). Although in vitro production may be the preferred alternative for the production of embryos of a known sex, the number of blastocysts produced might be reduced as compared with the use of non-sexed semen from the same bull.

183 IN VITRO EMBRYO PRODUCTION: A TOOL TO PRESERVE THE THREATENED WOOD BISON (BISON BISON ATHABASCAE)

2016 ◽  
Vol 28 (2) ◽  
pp. 222
Author(s):  
M. P. Cervantes ◽  
J. M. Palomino ◽  
M. Anzar ◽  
R. J. Mapletoft ◽  
G. Mastromonaco ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Animal Health ◽  
Developmental Competence ◽  
Bison Bison ◽  
High Humidity ◽  
Embryo Production ◽  
Wood Bison ◽  
In Vitro Embryo Production

In vitro embryo production is being developed as a tool to restore genetic diversity and eliminate endemic disease in wood bison. In a recent study in wood bison, we found that more oocytes reached maturity after 30 h v. 24 h of in vivo maturation following hCG treatment (Cervantes et al. 2014 Reprod. Fertil. Dev. 26, 199). An additional 4 h of in vitro maturation after an in vivo maturation period of 30 h also had a positive effect on developmental competence. The present study was designed to test the hypothesis that extending the in vivo maturation time (i.e. extending the interval between hCG treatment and cumulus-oocyte complex (COC) collection) from 30 to 34 h will improve in vitro embryo production in wood bison. Follicular wave development was synchronised among female wood bison (n = 28, 6 to 10 years old) by transvaginal follicular ablation. The study was done in 4 replicates (n = 7 bison per replicate). Bison were given FSH 1 day (300 mg) and 3 days (100 mg) after ablation for ovarian superstimulation, and hCG (2500 IU) 5 days after ablation to induce COC maturation in vivo. Bison were divided randomly into 2 groups (n = 14/group) in which COC were collected transvaginally at either 30 h or 34 h after hCG treatment. Expanded COC from the 30 h group were fertilised after 4 h of in vitro maturation, while expanded COC from the 34 h group were fertilised immediately. Oocytes and sperm were co-incubated (Day 0 = day of fertilization) for 18 h at 38.5°C in 5% CO2 in air and high humidity. Presumptive zygotes were cultured in 4-well dishes containing 500 μL well–1 of CR1aa medium at 38.5°C, 5% CO2, 5% O2, 90% N2 and high humidity, and assessed on Days 3, 7, and 8 (Day 0 = day of fertilization). Data were compared between groups by Chi-squared analysis. No effect of replicate was found. Compared to the 30 h group, the 34 h group had a greater cleavage rate [55/74 (74%) v. 49/86 (57%); (P < 0.05)], and a greater blastocyst rate on Day 7 [25/74 (34%) v. 9/86 (10%); (P < 0.05)] and Day 8 [(40/74 (54.1%) v. 32/86 (37.2%); (P < 0.05)]. We concluded that an extended period of in vivo maturation is beneficial for embryo production after in vitro fertilization in wood bison. We thank Vetoquinol Canada for providing FSH (Folltropin-V) and hyaluronan (MAP-5) and thank Merck Animal Health for hCG (Chorulon).

173 IN VITRO EMBRYO PRODUCTION FROM OOCYTES FERTILISED WITH UNSORTED OR X-SORTED SPERM AND ISSUED FROM SUBFERTILE HIGH GENETIC MERIT COWS SUBMITTED OR NOT TO A 48-h COASTING PERIOD FOLLOWING FSH STIMULATION

2016 ◽  
Vol 28 (2) ◽  
pp. 217
Author(s):  
G. Gamarra ◽  
S. Lacaze ◽  
C. Ponsart ◽  
M. Mouneyres ◽  
B. Le Guienne
Keyword(s):  
Embryonic Development ◽  
In Vitro Production ◽  
Genetic Progress ◽  
Embryo Production ◽  
Chi Square ◽  
Genetic Merit ◽  
In Vitro Embryo Production ◽  
Donor Cows

High genetic merit cows may be sidelined from breeding schemes because of reproductive disorders. In vitro production of embryos (IVP) issued from ovum pickup (OPU) can be an alternative to bypass infertility problems as experienced in humans and thus accelerate genetic progress (Duszewska et al. 2012 J. Anim. Feed Sci. 21, 217–233). The aim of this work was to evaluate if IVP from high genetic merit subfertile cows could benefit to the breeding scheme under commercial conditions, at the Biotechnology MIDATEST Station located in Denguin, Southwest, France. Holstein cows (n = 16) from 3.5 to 13 years old with different reproductive pathologic problems (repeated breeding, failure in in vivo embryo production, embryo mortality, permanent cysts, oviduct infection) were used in an OPU-IVP program. Donor cows were stimulated with decreasing doses pFSH twice daily during 3 days (Stimufol®, total dose: 350 µg of pFSH). The OPU was performed 48 h after the last FSH injection in the “coasting” group v. 12 h after the last FSH injection for “no-coasting” group and in vitro matured using a standard IVM protocol. Oocytes were fertilised with frozen-thawed unsorted or X-sorted sperm in TALP medium from different bulls (n = 42) without any previous IVP testing. Presumptive zygotes were cultured in SOF medium (Minitub®) plus 1% cow serum up to Day 7 at 38.5°C in 5% CO2, 5% O2, and 90% N2 atmosphere with maximum humidity. The OPU-IVP was repeated 1 to 6 times (3.75 ± 2.6) for each donor cow. Grade 1 blastocysts and expanded blastocysts (according to IETS classification) were recorded on Days 6.5 and 7. Embryo production was analysed with ANOVA and blastocyst yield was analysed by chi-square. The results in both coasting or no-coasting groups and the effect of fertilization using unsorted or X-sorted sperm are presented in Table 1. The embryonic development rate was significantly higher when using unsorted semen to fertilize the oocytes compared to X-sorted sperm (P < 0.05). On the other hand the coasting period had no significant effect neither on the number of collected oocytes nor on the embryonic development rates. In conclusion, our work confirmed the efficacy of OPU-IVP techniques to produce grade 1 embryos using X-sorted or unsorted sperm in subfertile high genetic merit cows. Table 1.Oocyte collection and in vitro embryo production, in donor cows submitted or not to a 48-h coasting period and effect of fertilization with unsorted v. X-sorted sperm

248 IN VITRO EMBRYO PRODUCTION USING IN VIVO-MATURED OOCYTES COLLECTED TRANSVAGINALLY FROM WOOD BISON (BISON BISON ATHABASCAE)

2015 ◽  
Vol 27 (1) ◽  
pp. 213
Author(s):  
M. P. Cervantes ◽  
J. M. Palomino ◽  
M. Anzar ◽  
R. J. Mapletoft ◽  
G. Mastromonaco ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Animal Health ◽  
Calf Serum ◽  
Developmental Competence ◽  
High Humidity ◽  
Embryo Production ◽  
Wood Bison ◽  
In Vitro Embryo Production

Reproductive technologies are being developed to help conserve the genetic diversity of wood bison, a threatened species. To date, the efficiency of in vitro embryo production in bison is very low and appears to be related to inadequate in vitro conditions for oocyte maturation. Recently, we have attempted to circumvent the problem by inducing oocyte maturation in vivo and found that more than one-third of superstimulated oocytes collected 30 h after administration of hCG were at metaphase II (Cervantes et al. 2013 Reprod. Fertil. Dev. 25, 283; Cervantes et al. 2014 Reprod. Fertil. Dev. 26, 199). We hypothesise that additional maturation time in vitro, after in vivo maturation, will allow the remaining oocytes to reach the MII stage, and thus improve in vitro embryo production in wood bison. The objective of this study was to determine the effect of an additional 4 h of in vitro maturation on the developmental competence of oocytes collected 30 h after hCG treatment. Wood bison cows (n = 24) were superstimulated by the administration of 300 mg of FSH (Folltropin-V) diluted in 0.05% hyaluronan on the day of follicular wave emergence and 100 mg of FSH in hyaluronan 2 days later. Bison were administered 2500 IU of hCG (Chorulon) IM 2 days after the last dose of FSH. Transvaginal ultrasound-guided follicle aspiration was performed 30 h after hCG treatment to collect cumulus-oocyte complexes (COC). Expanded COC (with no evidence of degeneration) were selected and assigned randomly to 2 groups (n = 38 COC/group) in which IVF was done immediately, or after 4 h of in vitro maturation in TCM 199 with 5% calf serum, 5 μg mL–1 pLH, 0.5 μg mL–1 pFSH, and 0.05 μg mL–1 gentamicin, at 38.5°C, 5% CO2 and high humidity. In vitro fertilization (Day 0) was done with frozen-thawed wood bison semen (dose 5 × 106 sperm mL–1) in Brackett-Oliphant medium at 38.5°C, 5% CO2, and high humidity. Presumptive zygotes were cultured in CR1aa plus 5% calf serum, at 38.5°C and in 5% CO2, 5% O2, and 90% N2 and high humidity. Cleavage was recorded on Day 3, and blastocyst formation was recorded on Days 7 and 8. Cleavage and blastocyst rates (calculated from the total number of oocytes submitted to IVF) were compared between groups by chi-square analysis. No difference was detected between groups (immediate fertilization v. after an additional 4 h in vitro) in cleavage rate on Day 3 (55.3 v. 60.5%, respectively, P = 0.82), or blastocyst rate on Day 7 (13.2 v. 23.7%, respectively, P = 0.37). However, the blastocyst rate on Day 8 was higher in the COC group exposed to an additional 4 h of in vitro maturation (18.4 v. 44.7%, respectively, P = 0.03). Results support the hypothesis that an additional short period of in vitro maturation improves the developmental competence of oocytes collected after 30 h of in vivo maturation.We thank Bioniche Animal Health for providing FSH (Folltropin-V) and hyaluronan (MAP-5), and Merck Animal Health for hCG (Chorulon).

106 COMPARISON OF IN VITRO EMBRYO PRODUCTION IN PANAMA USING HOLSTEIN OOCYTES WITH BOS INDICUS SEXED SEMEN FROM DONORS IN DIFFERENT LOCATIONS: FIELD DATA

2016 ◽  
Vol 28 (2) ◽  
pp. 183
Author(s):  
S. J. R. Rodriguez ◽  
Y. E. Ramirez ◽  
E. Gomes ◽  
L. F. Nasser ◽  
J. H. F. Pontes ◽  
...  
Keyword(s):  
Embryo Development ◽  
Bos Indicus ◽  
Embryo Production ◽  
University Of Illinois ◽  
Oocyte Collection ◽  
Sexed Semen ◽  
The Usa ◽  
In Vitro Embryo Production ◽  
The University

The objective of this work was to compare in vitro embryo production of Bos taurus × Bos indicus cross embryos using oocytes from Holstein donors under different production and environment systems. This study also examined the possibility for in vitro production using oocytes imported and transported fresh between the USA and Panama. All animals were mature Holstein cows going through a normal lactation. The first group of donors was from the University of Illinois dairy herd and went through 3 ovum pickup sessions. The second group of donors were Holstein cows already adapted to Panama and went through 10 ovum pickup sessions. The Panamanian herd of Holstein donors were born and raised in Panama in an area of mountains, on average 1300 m above sea level. This environment does not have the typical hot and humid tropical weather seen in other regions of Panama. Both groups of donors were aspirated without stimulation during the years 2013 and 2014. Oocytes recovered from donors in Illinois were imported fresh under a special sanitary research protocol between Panama and the University of Illinois. The transport of fresh oocytes from the USA to Panama was done using a portable incubator set at 39°C (Minutube of America). Oocytes were matured during transport in 5-mL tubes (~30–35 oocytes per tube) containing 400 µL of maturation media (TCM-199) that had been equilibrated with 5% CO2. Oocytes recovered from donors in Panama were matured using the same media. For both groups, oocytes were inseminated 24 h after ovum pickup using sexed semen from the same bull. All embryo production procedures followed the protocols of the In vitro Brasil™ commercial system. At 72 h postinsemination, cleavage was evaluated. On Day 7 after insemination, embryo development to the blastocyst stage (early to expanded) was recorded. Data were analysed using Chi-squared. As shown in Table 1, there was no effect of oocyte collection location on embryo development. These results indicate that it is possible to produce a viable in vitro-produced embryo using fresh oocytes collected and transported from different countries. This work opens the possibility to access superior genetics and improve herds in countries seeking to increase their production systems and potentially improve their quality of life. Table 1.Effect of oocyte collection location on embryo development This project was supported by Programa de Competitividad ProCom Senacyt, Panama.

257 DIFFERENCES BETWEEN BOS TAURUS AND BOS INDICUS EMBRYOS: TRANSCRIPTS AMOUNTS

2010 ◽  
Vol 22 (1) ◽  
pp. 285
Author(s):  
S. Wohlres-Viana ◽  
M. M. Pereira ◽  
A. P. Oliveira ◽  
J. H. M. Viana ◽  
M. A. Machado ◽  
...  
Keyword(s):  
Production System ◽  
Production Systems ◽  
Bos Taurus ◽  
Bos Indicus ◽  
In Vitro Production ◽  
Embryo Production ◽  
Peroxiredoxin 1 ◽  
Vitro Production

The Zebu breeds (Bos indicus) are different from European breeds (Bos taurus) in some aspects of their reproductive physiology, including follicle recruitment, number of follicular waves, and oocyte ultrastructure. On the other hand, embryos produced in vivo and in vitro show morphological and developmental differences, which can be related to culture environment. The aim of this study was to evaluate the effect of breed (Gyr v. Holstein) within embryo production system (in vivo and in vitro), as well as effect of production systems within breeds on relative abundance of transcripts related to formation, survival, and subsequent development of blastocysts, such as those involved in water and small solutes transport (Aquaporins 3 and 11), blastocoel formation (Na+/K+-ATPase a1 and |52), and cellular stress response (Peroxiredoxin 1). For in vivo embryo production, donors were superstimulated with FSH and inseminated, and embryos were recovered 7 days after AI. For in vitro embryo production, oocytes recovered by ovum pickup were in vitro matured and fertilized and then cultured for 7 days in culture medium under 5% CO2 at 38.5°C. For each group, blastocysts (n = 15) distributed in 3 pools were used for RNA extraction (RNeasy MicroKit, Qiagen, Valencia, CA, USA), followed by RNA amplification (Messageamp II amplification kit, Ambion-Applied Biosystems, Foster City, CA, USA) and reverse transcription (SuperScript III First-Stand Synthesis Supermix, Invitrogen, Carlsbad, CA, USA). The cDNA were submitted to real-time PCR, using the H2a gene as endogenous control, and analyzed by REST© software. To evaluate breed effect within the production systems, 2 comparisons were performed: (1) in vivo: Gyr v. Holstein and (2) in vitro: Gyr v. Holstein, considering Holstein data as 1.00. To evaluate production system effect within breeds, 2 comparisons were performed: (1) Gyr: in vivo v. in vitro and (2) Holstein: in vivo v. in vitro, considering in vivo produced embryo data as 1.00. The results are shown as mean ± SEM. For in vivo comparison between breeds, Aquaporin 3 (1.66 ± 0.77), Na+/K+-ATPase a1 (1.61 ± 0.56), and Peroxiredoxin 1 (1.61 ± 0.66) were up-regulated (P < 0.05) in Gyr embryos when compared with Holstein embryos, whereas for in vitro comparison, no differences (P > 0.05) were found. For comparisons between production systems within breeds, only Peroxiredoxin 1 (0.31 ± 0.39) was down-regulated (P < 0.01) in in vitro produced Gyr embryos when compared with in vivo counterparts. No differences (P > 0.05) were found between production systems for the Holstein breed. In conclusion, these data suggest that there is a difference on gene expression between Bos taurus and Bos indicus blastocysts, but such difference between breeds can be attenuated by the in vitro production system, indicating an embryo adaptation to the in vitro culture conditions. The data also suggest that the in vitro production system can influence the amount of transcripts in Gyr embryos. Other genes should be evaluated for a better understanding of these differences. Financial support was provided by CNPq and FAPEMIG.

Predictive value of in vitro embryo production characteristics for in vivo fertility of bulls

1997 ◽  
Vol 47 (1) ◽  
pp. 259 ◽  
Author(s):  
L.M.T.E. Lansbergen ◽  
E.H.A.T. Hanenberg ◽  
A.M. van Wagtendonk-de Leeuw
Keyword(s):  
Predictive Value ◽  
Embryo Production ◽  
In Vitro Embryo Production ◽  
Production Characteristics

scholarly journals 279VASCULAR MORPHOMETRY OF BOVINE PLACENTOMES IN LATE GESTATION FROM EMBRYOS PRODUCED IN VIVO OR IN VITRO

2004 ◽  
Vol 16 (2) ◽  
pp. 259
Author(s):  
J.R. Miles ◽  
C.E. Farin ◽  
K.F. Rodriguez ◽  
J.E. Alexander ◽  
P.W. Farin
Keyword(s):  
Blood Vessels ◽  
Maternal Blood ◽  
Volume Density ◽  
Late Gestation ◽  
Embryo Production ◽  
Vascular Volume ◽  
Treatment Groups ◽  
In Vitro Embryo Production

The role of the vascular supply in the development of placentas from embryos produced in vitro is poorly understood. The objective of this study was to determine the effects of in vitro embryo production on morphometry of blood vessels within fetal (cotyledonary) and maternal (caruncular) components of the placentome during late gestation. In vivo-produced embryos were recovered from superovulated Holstein cows on Day 7 after estrus. For in vitro embryo production, oocytes were aspirated from the ovaries of Holstein cows, matured in vitro, and then fertilized. Presumptive zygotes with their cumulus cells were transferred into M-199 with 10% estrus cow serum and cultured for 168h post-insemination. Semen from the same Holstein sire was used for the production of in vivo and in vitro embryos. Single blastocysts from each production system were transferred into the uteri of heifers. On Day 222 of gestation, fetuses and placentas were recovered in utero (in vivo, n=12; in vitro, n=12). Placentomes were collected, fixed and sectioned. Fetal and maternal blood vessels were identified within placentome sections using immunocytochemistry for vascular endothelial growth factor (VEGF) protein. A total of 4.8×105μm2 of tissue were examined from each placentome. Stereological methods were used to determine the volume densities of fetal and maternal blood vessels. Data were analyzed by GLM procedures. Fetuses were heavier (P=0.03) in the in vitro group (20.7±1.0kg, LS mean±SEM) compared to the in vivo group (17.3±1.0kg). Placentas were also heavier (P=0.06) for the in vitro group (2.5±0.2kg) compared to the in vivo group (2.0±0.2kg). Placental efficiency, calculated as fetal weight/placental weight, was similar between the two treatment groups (9.0±0.5 and 8.9±0.5 for in vivo and in vitro, respectively). Fetal vascular volume density in placentomes was not different between the two treatment groups (5.4±0.3% and 5.4±0.3% for in vivo and in vitro, respectively). In contrast, maternal vascular volume density was greater (P=0.02) for placentomes in the in vitro group (5.9±0.3%) compared to in vivo controls (4.9±0.3%). In summary, compared to placentomes from embryos produced in vivo, placentomes from embryos produced in vitro had similar volume density of fetal vessels, but had significantly increased volume density of maternal vessels. Supported by the State of North Carolina.

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