scholarly journals Effect of Ferula communis L. on reproductive parameters in Awassi ewes

2019 ◽  
Vol 70 (3) ◽  
pp. 1625
Author(s):  
A.G. ONAL

Nutrient composition of the diet affects follicular activity, embryonic development and reproductive hormones in ruminants. The objective of the present study was to investigate the effects of Ferula communis L. on some reproductive parameters of Awassi sheep. The experiment was carried out on 29 (15-16 months old) Awassi ewes. All ewes were allocated to receive either a control (14% CP and 11.7 MJ ME/kg, n=9) or a diet supplemented with 5% (75g, n=10) or 10% (150g, n=10) powdered F. communis root, respectively for 21 days. Oestrus was synchronized using intravaginal sponges, while oestrus behaviour was observed 24, 36 and 48h after the sponge removal. Blood samples were collected for the assessment of oestradiol and LH. At the end of the 21-day period, animals were slaughtered and ovarian structures were recorded. Corpora lutea tissues were cultured in vitro, and progesterone production was measured. The results indicate that the treatment of animals with 5% of F. communis root increased the percentage of animals in heat (80%, 60% and 10% for 5C, 10C, and the control group, respectively). Furthermore, the number of small follicles (1-3 mm) in treated groups was significantly higher than those of the control group. Moreover, the number of large follicles (>4 mm) in the control group was higher than those of the treatment groups. Plasma concentration of oestrogen and LH peak were similar in the control and treatment groups. Progesterone production by luteal cells cultured in vitro was higher for both treatment groups compared to the control. Herewith, supplementation of the diet of Awassi Sheep with F. communis root during the breeding season may enhance ovulation rate and luteal activity. 

1995 ◽  
Vol 7 (1) ◽  
pp. 35 ◽  
Author(s):  
Vecchio RP Del ◽  
JK Thibodeaux ◽  
R Saatman ◽  
W Hansel

The effects of contact between large and small bovine luteal cells together with those of luteinizing hormone (LH) or arachidonic acid (AA) on progesterone production during the oestrous cycle were investigated. Corpora lutea were collected during the mid-luteal stage (Days 10-12; n = 4) and late-luteal stage (Days 17-18; n = 4) of the oestrous cycle. Large and small luteal cells were dispersed and separated and then incubated together or separately. Mid-luteal stage cells were treated with LH (0 or 5 ng) whereas late-luteal stage cells were treated with LH (0 or 5 ng) or AA (0 or 10 microM). Culture medium was collected and replaced 1, 3 and 6 h after starting treatments. Progesterone production decreased (P < 0.0001) with increased incubation time irrespective of cell arrangement, the stage of the oestrous cycle or treatment. During the 18 h before treatment, cells in the contact arrangement produced more progesterone (P < 0.003) than cells without contact in both mid- and late-luteal stages of the oestrous cycle; progesterone production within cell arrangements between prospective treatment groups was similar. After initiating treatments, mid-luteal stage cells in the control group without contact produced more progesterone (P < 0.01) than cells with contact. Mid-luteal stage cells treated with LH produced more (P < 0.0001) than control cells; progesterone production between cell arrangements within the LH treatment group was similar. In the late-luteal stage cells, both LH and AA increased (P < 0.01) progesterone production by comparison with control cells; LH and AA treatment groups produced similar results.(ABSTRACT TRUNCATED AT 250 WORDS)


1981 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON

Cell suspensions were prepared from tissue samples of human corpora lutea obtained during the mid- and late-luteal phase of the menstrual cycle. Both oestradiol and progesterone production by dispersed cells were stimulated by similar concentrations of human chorionic gonadotrophin (hCG). As the degree of stimulation of production by hCG was greater for progesterone than for oestradiol (five- to tenfold compared with two- to threefold higher than basal production), the ratio of progesterone to oestradiol produced varied according to the level of trophic stimulation. A comparison of cell suspensions prepared from mid- and late-luteal phase corpora lutea, exposed to the same concentration of hCG (10 i.u./ml) in vitro, did not reveal a shift to oestradiol production in the late-luteal phase. Provision of additional testosterone during incubation raised the level of oestradiol production by dispersed luteal cells. At an optimum concentration of testosterone (1 μmol/l), oestradiol synthesis was not raised further in the presence of hCG or N6, O2-dibutyryl cyclic AMP, suggesting a lack of induction or activation of the aromatase system by gonadotrophin in short-term cultures. Basal and stimulated levels of progesterone production were not significantly impaired in the presence of testosterone.


2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Elizabeth A. Lakota ◽  
Justin C. Bader ◽  
Voon Ong ◽  
Ken Bartizal ◽  
Lynn Miesel ◽  
...  

ABSTRACT CD101 is a novel echinocandin with concentration-dependent fungicidal activity in vitro and a long half-life (∼133 h in humans, ∼70 to 80 h in mice). Given these characteristics, it is likely that the shape of the CD101 exposure (i.e., the time course of CD101 concentrations) influences efficacy. To test this hypothesis, doses which produce the same total area under the concentration-time curve (AUC) were administered to groups of neutropenic ICR mice infected with Candida albicans R303 using three different schedules. A total CD101 dose of 2 mg/kg was administered as a single intravenous (i.v.) dose or in equal divided doses of either 1 mg/kg twice weekly or 0.29 mg/kg/day over 7 days. The studies were performed using a murine disseminated candidiasis model. Animals were euthanized at 168 h following the start of treatment. Fungi grew well in the no-treatment control group and showed variable changes in fungal density in the treatment groups. When the CD101 AUC from 0 to 168 h (AUC0–168) was administered as a single dose, a >2 log10 CFU reduction from the baseline at 168 h was observed. When twice-weekly and daily regimens with similar AUC values were administered, net fungal stasis and a >1 log10 CFU increase from the baseline were observed, respectively. These data support the hypothesis that the shape of the CD101 AUC influences efficacy. Thus, CD101 administered once per week demonstrated a greater degree of fungal killing than the same dose divided into twice-weekly or daily regimens.


2005 ◽  
Vol 17 (2) ◽  
pp. 219 ◽  
Author(s):  
C.E. Ferguson ◽  
T.R. Davidson ◽  
M.R.B. Mello ◽  
A.S. Lima ◽  
D.J. Kesler ◽  
...  

There has been much debate over a direct role for progesterone (P4) in early bovine embryo development. While previous attempts to supplement bovine embryos in vitro with P4 produced results that vary and are often contradictory, this may be a response of administering P4 at inappropriate times. Therefore, the objective of these experiments was to determine if P4 could exert a direct effect on developing IVF-derived bovine embryos when administered at an appropriate time of embryo development. In Exp. I, IVF-derived bovine 8-cell embryos were randomly allotted to treatments: (1) control, CR1aa medium (n = 168); (2) vehicle, CR1aa + ETOH (0.01%) (n = 170); and (3) P4, CR1aa + ETOH + P4 (20 ng/mL in 50-μL droplet) (n = 173). In Exp. II, IVF-derived bovine 8-cell embryos were randomly allotted to treatments: (1) control, CR1aa medium (n = 160); (2) vehicle, CR1aa + DMSO (0.01%) (n = 180); and (3) P4, CR1aa + DMSO (0.01%) + P4 (20 ng/mL in 50-μL droplet) (n = 170). All embryos were evaluated on Days 6 to 9 post-insemination and rates calculated from 8-cell embryos. In Exp. I, ETOH tended to have a detrimental effect with significantly fewer (P < 0.05) embryos (53%) developing to the blastocyst stage on Day 7 compared with the control (62%) and P4 (71%) groups. At Day 7, significantly more embryos cultured in P4 (71%) developed to the blastocyst stage compared with the control group (62%). P4 treatment significantly increased the number of Grade 1 blastocysts (25%) on Day 7 compared with vehicle (15%) and control (17%) groups. At the end of culture, there were also significantly more Day 9 hatched blastocysts in the P4 group (33%) compared with vehicle (22%) and control (21%) groups. Supplementing P4 in the culture medium increased the rate of development, resulting in significantly more blastocysts (8%) on Day 6 and hatched blastocysts (21%) on Day 8 compared with vehicle (3% and 12%) and control (0% and 8%) groups, respectively. In Exp. II, there were no significant differences between treatment groups for Day 7 blastocysts (control 54%, DMSO 61%, P4 57%) and Day 9 hatched blastocysts (control 46%, DMSO 51%, P4 46%). However, there were significantly more Grade 1 blastocysts in the P4 group (22% and 36%) on Days 6 and 8 compared with vehicle (11% and 23%) and control (13% and 23%) groups, respectively. The lack of improvement in Day 7 blastocysts and Day 9 hatched blastocysts rates leads to further uncertainty in understanding the P4 vehicle interactions. In conclusion, the results of these two experiments indicate that P4 can exert a direct effect on the developing IVF-derived bovine embryo; however, due to P4 vehicle interactions; other inert vehicles need to be explored to further evaluate the direct effects of P4 on the developing bovine embryo.


2004 ◽  
Vol 9 (1) ◽  
Author(s):  
M.G.L. PINTO ◽  
M.I.B. RUBIN ◽  
C.A.M. SILVA ◽  
T.F. HILGERT ◽  
M.F. SÁ FILHO ◽  
...  

O desenvolvimento embrionário de oócitos bovinos maturados in vitro (MIV) foi avaliado em meio suplementado com líquido folicular eqüino (Lfe). Foram distribuídos 1045 oócitos em 11 repetições formando três grupos tratamentos (T1, T2, T3) e um controle (C). O meio de maturação utilizado foi o TCM-199 acrescido de piruvato de sódio, hormônio folículo estimulante recombinante (rFSHh) e hormônio luteinizante equino (LHe). Suplementou-se esse meio com 10% de soro de égua em estro para o grupo controle e para T1, T2 e T3, o meio foi suplementado com 5, 10, e 20% de LFe, respectivamente. Os oócitos foram maturados in vitro (MIV) por 24h. A fecundação in vitro (FIV) foi realizada em meio Talp-Fert. A MIV e a FIV foram realizadas em estufa a 39ºC com 5% de CO2 em ar e umidade saturada. Os zigotos foram cultivados em meio SOFaaci, sob óleo mineral no interior de bolsas plásticas gaseificadas. As taxas de clivagem e de blastocistos foram observadas diariamente (D), e em D7, foram superiores (P0,05) às do grupo controle. Em D9, a taxa de blastocistos do T2 foi superior (P0,05). O LFe, na concentração de 10% pode ser utilizado, em substituição ao soro de égua em estro para suplementar o meio de MIV de oócitos bovinos. Equine follicular fluid on in vitro maturation of bovine oocytes Abstract Embryo development of bovine oocytes was evaluated using maturation medium supplemented with equine follicular fluid (eFF). One thousand and forty five (1045) oocytes were distributed in 11 replications forming three treatment groups (T1, T2 e T3) and one Control (C). TCM-199 added with sodium pyruvate, rFSHh and LHe was used as maturation medium. This medium was supplemented with 10% estrous mare serum for Control group, and 5, 10, and 20% eFF, respectively, for T1, T2 e T3 groups. In vitro maturation (IVM) of all groups was performed during 24h. In vitro fertilization (IVF) was performed in TALP-FERT medium. IVM and IVF were carried out in an incubator at 39ºC with 5% CO2 in air and saturated humidity. Zygotes were cultured in SOFaaci medium, under mineral oil in gasified bags. Cleavage and blastocyst rates were daily observed (D), and at D7, were higher (P0.05) for those from control group. At D9, blastocyst rate of T2 was higher (P0.05). The eFF, at a 10% concentration, can replace the use of estrous mare serum to supplement the IVM medium of bovine oocytes.


2001 ◽  
Vol 168 (1) ◽  
pp. 141-151 ◽  
Author(s):  
C Boiti ◽  
D Zampini ◽  
M Zerani ◽  
G Guelfi ◽  
A Gobbetti

Studies were conducted to characterize receptors for prostaglandin (PG) F(2alpha) (PGF(2alpha)) and PGE(2), and the signalling pathways regulating total nitric oxide synthase activity and progesterone production in rabbit corpora lutea (CL) of different luteal stages. CL were obtained at days 4, 9 and 13 of pseudopregnancy and cultured in vitro for 2 h with PGF(2alpha) or PGE(2) and with activators and inhibitors of G protein (Gp), phospholipase C (PLC), protein kinase C (PKC), adenylate cyclase (AC) and protein kinase A (PKA). High affinity PGF(2alpha) receptor (K(d)=1.9+/-0.6 nM mean+/-s.e.m. ) concentrations increased (P< or =0.01) four- to five-fold from early to mid- and late-luteal phases (50.6+/-8.5, 188.3+/-36.1 and 231.4+/-38.8 fmol/mg protein respectively). By contrast, PGE(2) receptor (K(d)=1.6+/-0.5 nM) concentrations decreased (P< or =0.01) from day 4 to day 9 and 13 (27.5+/-7.7, 12.4+/-2.4 and 16.5+/-3.0 fmol/mg protein respectively). The Gp-dependent AC/PKA pathway was triggered only on day 4 CL, mimicking the PGE(2) treatment and increasing progesterone production. In both day 9 and day 13 CL, the Gp-activated PLC/PKC pathway evoked a luteolytic effect similar to that induced by PGF(2alpha). The time-dependent selective resistance to PGF(2alpha) and PGE(2) by rabbit CL is mediated by factors other than a lack of luteal receptor-ligand interactions.


2007 ◽  
Vol 19 (1) ◽  
pp. 294
Author(s):  
J.-K. Tseng ◽  
P.-C. Tang ◽  
J.-C. Ju

Elevated ambient temperature has been known to be deleterious to the developmental competence of mammalian oocytes and embryos, although the mechanism is still unclear. The objective of this study was to determine the effect of heat shock (HS) on the alteration of intracellular calcium concentrations ([Ca2+]i) of matured pig oocytes by two different calcium releasing agents. Porcine cumulus–oocyte complexes were aspirated from the follicles (3–6 mm) and subjected to standard in vitro maturation procedure for 42 h. Matured oocytes were then randomly allocated to different heat treatments at 41.5°C for 0 (Control, C0h), 1 (HS1h), 2 (HS2h), or 4 h (HS4h). An additional control group was cultured for 4 h without heat shock (C4h). Oocytes were incubated with 2 µM fura-2 acetoxymethyl ester (AM) and 0.02% pluronic F-127 in Ca2+-free PBS (40 min) following heat shock, and then washed with Ca2+-free PBS (30 min) for detection of [Ca2+]i. Fluorescent images were captured with alternative excitation wavelengths at 340/380 nm by a rotating chopper disk equipped with an Axon imaging system. Data from both experiments were analyzed by ANOVA using the General Linear Model (GLM) of the SAS (SAS Institute, Inc., Cary, NC, USA). In Experiment 1, matured oocytes were activated by 200 mM thimerosal (10 min) following heat treatment. The maximal [Ca2+]i in the HS2h group was the highest among all treatment groups. The lowest maximal peak of [Ca2+]i was observed in the HS4h group, but it was still higher than that in the C4h group (P < 0.05). The total amount of Ca2+ release represented by the total area of the peaks in C4h was lower than in any other groups except HS4h (P < 0.05). In Experiment 2, each matured oocyte was injected with approximately 10 pL of inositol 1,4,5-triphosphate (IP3, 0.5 mM); the Ca2+ transient was recorded as described in the previous experiment. The maximal value of [Ca2+]i in the C4h group was still the lowest among the heat-shocked and C0h groups (P < 0.05). The total Ca2+ release in the HS2h group was the highest among all treatment groups, but only significantly higher than the HS1h and C4h groups (P < 0.05). A similar pattern of Ca2+ release in HS-oocytes was induced by thimerosal and IP3 stimulations. These results indicate that Ca2+ releasing capacity of matured pig oocytes is enhanced by a shorter duration of heat shock, but declines after prolonged exposure of heat shock and/or in vitro culture. The differential Ca2+ releasing capacity of heat-shocked oocytes prior to fertilization revealed physiological changes of pig oocytes after heat shock. This finding provides further insight for the low fertilization and developmental competence that occurs in farm species during hot seasons.


2011 ◽  
Vol 23 (1) ◽  
pp. 263
Author(s):  
F. Pereyra-Bonnet ◽  
A. Gibbons ◽  
M. Cueto ◽  
R. Bevacqua ◽  
L. Escobar ◽  
...  

Microinjection of DNA into the male pronucleus is a commonly used method to generate transgenic animals. However, it is only moderately efficient in several species because it requires proper male pronuclear visualisation, which occurs only in a narrow window of time in mice. The cytoplasmic microinjection of exogenous DNA (eDNA) is an alternative method that has not been fully investigated. Our objective was to evaluate if cytoplasmic microinjection of eDNA is capable of producing genetically modified embryos. In vitro and in vivo derived sheep embryos were cytoplasmically microinjected with pCX-EGFP previously incubated (5 min in a PVP droplet) with oolemma-cytoplasm fragments obtained from donor oocytes by microsurgery. A control group using microinjected plasmid alone was included in the in vivo procedure. For in vitro microinjection, IVF embryos were microinjected with circular plasmid with promoter (50 or 500 ng μL–1) or without promoter (50 ng μL–1) at 6 h after fertilization. The IVF was performed following (Brackett and Olliphant 1975 Biol. Reprod. 12, 260–274) with 15 × 106 spermatozoa mL–1, and presumptive zygotes were cultured in SOF. The expression of enhance green fluorescent protein (EGFP) was determined under blue light. For in vivo microinjection, embryos from superovulated sheep (by standard procedures) were recovered and microinjected with 50 ng μL–1 of linearized plasmid without promoter at 12 h after laparoscopic insemination with frozen semen (100 × 106 spermatozoa per sheep). Plasmid without promoter was used to avoid any possible cytotoxic effect produced by EGFP expression. The microinjection of IVF embryos with 50 ng μL–1 of plasmid was the best condition to produce embryos expressing eDNA (n = 96; 46.9% cleaved; 12.2% blastocysts; 53.0 and 4.1% of green embryos and blastocysts, respectively). Variables between the groups with or without promoter IVF were not statistically different (Fisher test: P < 0.05); however, when 500 ng μL–1 was microinjected, no blastocysts were obtained. In the in vivo embryo production group, 111 presumptive zygotes were microinjected (n = 37; with plasmid alone) from 16 donor sheep (11.5 ± 4.0 corpora lutea; 8.4 ± 4.8 presumptive zygotes recovered; 74.3% recovery rate). The mean time from injection to cleavage was 18.0 ± 4.5 h, and the percentage of cleavage and damage (due to the embryo injection) were >70% and <10%, respectively. Fifty-eight good quality embryos were transferred into the oviducts of 19 surrogate ewes; 12 of them are pregnant (63.1%). The presence of green IVF embryos demonstrates that eDNA was transported to the nucleus after cytoplasmic injection. We believe that the multi-fold increase (50- to 100-fold) in plasmid concentration compared with that used by others was the key step to our successful cytoplasmic microinjection. Accordingly, the new/old methodology described in this study provides an easy DNA construct delivery system of interest for the implementation of early reprogramming events. In addition, results obtained in the near future using in vivo cytoplasmic microinjection with high concentrations of eDNA could revalidate this technique for producing genetically modified large animals.


2009 ◽  
Vol 21 (1) ◽  
pp. 205
Author(s):  
K. E. Park ◽  
R. Cabot

Methylation of the lysine 9 residue of histone H3 (H3K9) is linked with repression of transcription. Dimethylated H3K9 adopts a strict asymmetrical distribution in murine zygotes, with dimethylated H3K9 detectable only on maternally derived chromatin. In contrast, both male and female pronuclei in porcine zygotes can possess dimethylated H3K9; however, some asymmetry in H3K9 dimethylation exists between individual pronuclei, particularly in polyspermic embryos. The objective of this study was to determine the extent that DNA, mRNA, and protein synthesis serve in maintaining the asymmetrical distribution of dimethylated H3K9 in porcine zygotes. We hypothesized that the distribution of dimethylated H3K9 between individual pronuclei would not depend on alternations in chromatin structure induced by DNA or mRNA synthesis but would be affected by protein synthesis. To test this hypothesis, in vitro-matured porcine oocytes were fertilized in vitro, cultured in porcine zygote medium-3 containing 3 mg mL–1 of BSA, and allocated to 1 of 4 treatment groups: (1) incubation with 25 μg mL–1 of α-amanitin (α-AM), (2) incubation with 3 μg mL–1 of aphidicolin (APH), (3) incubation with 50 μg mL–1 of cycloheximide (CYC), and (4) nontreated controls. Embryos were removed from each treatment group at 10, 15, 20, and 25 h post gamete mixing, fixed, and processed to detect dimethylated H3K9 immunocytochemically. For monospermic embryos in the control group, 24% (7/29), 31% (8/26), 30% (7/24), and 20% (4/20) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the control group, 82% (32/39), 78% (31/40), 74% (28/38), and 65% (24/37) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For monospermic embryos in the α-AM group, 29% (4/14), 14% (2/14), 8% (1/12), and 11% (1/9) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the α-AM group, 71% (15/21), 63% (12/19), 55% (10/18), and 47% (8/17) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For monospermic embryos in the APH group, 31% (4/13), 23% (3/13), 23% (3/13), and 18% (2/11) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the APH group, 75% (15/20), 67% (12/18), 63% (12/19), and 56% (10/18) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For monospermic embryos in the CYC group, 33% (5/15), 25% (4/16), 14% (2/14), and 9% (1/11) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the CYC group, 78% (18/23), 67% (16/24), 58% (14/24), and 59% (13/22) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. These results suggest that the distribution of dimethylated H3K9 between pronuclei is not affected by DNA, mRNA, or protein synthesis (P > 0.05), but is affected by the age of the pronuclei (P < 0.05).


2015 ◽  
Vol 27 (1) ◽  
pp. 143
Author(s):  
F. Randi ◽  
B. Fernandez ◽  
M. McDonald ◽  
C. Johnson ◽  
N. Forde ◽  
...  

Maternal progesterone (P4) regulates early conceptus growth and development in ruminants. Early embryo transfer studies in sheep and cattle demonstrated a need for close synchrony between the embryo and the uterine environment of the recipient. However, manipulating P4 may be one way of strategically regulating the temporal changes that normally occur in the uterine environment in order to allow flexibility in the timing of embryo transfer. For example, previous studies have demonstrated that P4 administration during the first few days of the oestrous cycle facilitates pregnancy establishment with older embryos. The aim of this study was to examine the effect of embryo-uterine synchrony on conceptus elongation in cattle. Oestrous cycles of crossbred beef heifers were synchronised using an 8-day P4-Releasing Intravaginal Device (PRID Delta®, CEVA, Mountain View, CA, USA) with administration of a prostaglandin F2α analogue (Enzaprost®, CEVA; 5 mL equivalent to 25 mg of dinoprost) given on the day before PRID removal. Heifers were checked for signs of oestrus 4 times per day commencing 30 h after PRID withdrawal. Only those seen in standing oestrus (n = 50) were randomly assigned to 1 of 5 treatment groups to receive Day 7 in vitro-produced blastocysts (n = 10 per recipient) (1) on Day 5 post-oestrus; (2) on Day 5, with P4 supplementation via PRID from Day 3 to 5 + 750 IU of eCG at PRID insertion; (3) on Day 5, PRID Delta from Day 3 to 5 plus 3000 IU of hCG at PRID insertion; (4) on Day 7, or (5) on Day 9. At embryo age Day 14, all heifers were slaughtered and the uterus was flushed to recover and measure conceptuses. Data are summarised in Table 1. Fewer recipients yielded conceptuses (P < 0.05) and fewer conceptuses overall were recovered (P < 0.05) following transfer on Day 5 compared with Day 7 or Day 9. Supplementation with P4 resulted in short cycles (evidenced by corpus luteum regression and/or a recent ovulation at slaughter) in 33.3 to 54.5% of recipients receiving embryos on Day 5. Mean conceptus length was greater (P < 0.05) following transfer to an advanced uterus. In conclusion, transfer of embryos to a retarded (Day 5) uterine environment results in poor embryo survival. Supplementation with P4 shortened the interoestrous period in a significant number of heifers. Transfer to an advanced uterine environment promotes conceptus elongation, presumably driven by P4. Table 1.Embryo survival and conceptus length data


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