Development of persistent ovarian follicles during synchronization of estrus influences the superovulatory response to FSH treatment in cattle

The synchronization of estrus with synthetic progestins or progesterone (P(4)) results in the development of a large, persistent ovarian follicle. The objectives of the present study were to determine if development of a persistent ovarian follicle during synchronization of estrus suppresses recruitment of additional follicles during FSH treatment. On Day 5 of the estrous cycle (estrus = Day 0), beef cows were treated with 0.5 or 2.0 P(4) releasing intravaginal devices (PRIDs) for 8 d (Experiment 1, n = 20), 5 or 2 d (Experiment 2, n = 44) before initiation of FSH treatment. Prostaglandin F(2alpha) (25 mg) was administered on Days 5 and 6. Superovulation was induced with 24 mg of recombinant bovine FSH (rbFSH, Experiment 1) or 28 mg of FSH-P (Experiment 2) over a 3- or 4-d period, respectively. The PRIDs were removed concurrently with the 5th injection of rbFSH or FSH-P. There was a treatment-by-day interaction (P < 0.001) for the concentration of 17beta-estradiol in cows treated for 8, 5 or 2 d before FSH treatment. In Experiment 1, FSH treatment initiated 8 d after insertion of a 0.5 PRID did not affect the number of CL (6.9 +/- 1.4 vs 6.7 +/- 1.6), ova/embryos (3.7 +/-1.3 vs 3.0 +/- 1.3) and transferable embryos (2.4 +/- 0.9 vs 3.0 +/- 0.9) compared with that of the 2.0 PRIDs. In Experiment 2, FSH treatment initiated 5 d after insertion of a 0.5 PRID decreased the number of CL (4.0 +/- 0.5 vs 8.3 +/- 0.8; P < 0.001), ova/embryos (3.0 +/- 0.6 vs 5.9 +/- 1.2; P < 0.03) and transferable embryos (2.3 +/- 0.6 vs 5.1 +/- 1.0; P < 0.03) compared with that of a 2.0 PRID, respectively. Initiation of FSH treatment 2 d after insertion of a 0.5 PRID compared with a 2.0 PRID had no affect on the number of CL (8.0 +/- 2.1 vs 8.7 +/- 1.2), total ova (4.8 +/- 1.4 vs 6.9 +/- 1.4) and transferable embryos (2.9 +/- 1.2 vs 6.1 +/- 1.7). In conclusion, treatment with low doses of P(4) (0.5 PRID) for 5 d but not for 2 or 8 d before initiation of FSH treatment results in the development of a dominant ovarian follicle, which reduces recruitment of ovarian follicles, and the number of CL, total ova and transferable embryos.     

Effects of breed, age of donor and dosage of follicle stimulating hormone on the superovulatory response of beef cows

Data were obtained on 1039 recoveries of embryos from beef cows of four breeds at two locations, in clinic and on farm. General linear models procedures were utilized to determine the effects of breed, location, age of donor, dosage of follicle stimulating hormone (FSH) and the interaction of age and FSH on the following dependent variables: 1) the mean number of ova (unfertilized oocytes and embryos) recovered; 2) the mean number and percentage of embryos (fertilized; live and dead) recovered; and 3) the mean number and percentage of transferable embryos recovered. The interaction of age of donor and dosage of FSH with breed and location prevented the pooling of data over breed and location. The mean number of ova recovered was affected by age of the donor (Charolais-in clinic), or the interaction between age of donor and dosage of FSH (Polled Hereford-in clinic and -on farm and Simmental -on farm). The mean number of embryos was affected by age of donor (Polled Hereford-in clinic), dosage of FSH (Simmental-in clinic) or their interaction (Angus-on farm). The mean number of transferable embryos was affected by age of donor (Polled Hereford-in clinic and -on farm, Simmental-in clinic and Angus-on farm). General linear models procedures were utilized to determine the effects of the embryo (stage of development and quality) and the recipient (synchrony with the donor) on the rate of pregnancy. Rate of pregnancy varied with embryo quality score and synchrony of the recipient and the embryo. In conclusion, the superovulatory response was found to be highly breed-specific, and most of the variability in embryos produced was attributed to the number of ova recovered. However, the number of ova, embryos and transferable embryos recovered was further influenced by age of the donor, dosage of FSH or their interaction.     

Embryo transfer in fallow deer (Dama dama): superovulation, embryo recovery and laparoscopic transfer of fresh and cryopreserved embryos

Multiple ovulation-embryo transfer (MOET) protocols for farmed fallow deer (Dama dama ) were investigated in a series of 3 experiments. A total of 37 donors, of either European (D.d. dama ; n = 30) or Mesopotamian hybrid (D.d. mesopotamica x D.d. dama ; n =7) genotype, each received an intravaginal silastic device containing 0.3 g progesterone (CIDR((R))-type G device) for 14 d and injections of 0.5 units ovine FSH (8 x 0.06 unit injections from Days 10 to 14 of device insertion) and 100 IU PMSG (either with the first or last FSH injection). All donors received laparoscopic intrauterine inseminations of fresh semen (50 x 10(6) spermatozoa) from a Mesopotamian sire 36 h after withdrawal of CIDR((R)) devices. Embryos were recovered by laparotomy on Day 6 (Day 0 = estrus). Mean ovulation rates for the 3 experiments were 8.1, 9.8 and 7.0, with no effect of PMSG timing (P>0.10). However, embryo recovery rates, albeit low throughout the study (29.6%), were significantly improved with later PMSG administration (33.9 vs 20.1%; P<0.05). Hybrid and European donors performed in a similar manner. A range of embryo development stages was recovered throughout the study. In 2 experiments laparoscopic transfer of embryos to 48 recipient does treated previously with intravaginal CIDR((R)) devices for 14 d yielded a total pregnancy rate of 37.5%. In the experiment with fresh embryos, the use of clenbuterol to reduce uterine turgidity resulted in a higher proportion of does conceiving (3 4 ; 75%) compared with that of the untreated does (0 6 , 0%; P<0.05). In the second experiment, in which all the does routinely received clenbuterol, 10 19 (53%) and 5 19 (26%) does conceived following the transfer of fresh and cryopreserved embryos, respectively (P<0.05). While the overall efficiency of the MOET program was low (equivalent of 0.9 to 1.0 surrogate pregnancies per donor), improvements in the recovery rate of transferable embryos have considerable potential for genetic improvement of farm stock and captive propagation of endangered Mesopotamian fallow deer through maternal surrogacy programs.     

Assessment LOPU-IVF in Japanese sika deer (Cervus nippon nippon) and application to Vietnamese sika deer (Cervus nippon pseudaxis) a related subspecies threatened with extinction

In mammals, recovery of oocytes by laparoscopic ovum pick-up (LOPU) coupled with in vitro production (IVP) of embryos represents a promising strategy for both amplification and genetic management of sparse animals from captive endangered wild species. As integrated technique developed mainly for domestic livestock, LOPU-IVP requires several studies to set up protocols for follicular stimulation or optimization of IVP before envisaging successful transposition to wild species. In deer, many endangered subspecies would be potentially concerned by applying such an approach using common subspecies for protocols optimization. The aim of the present study was to assess efficiency of follicle stimulation using ovine FSH (oFSH) for recovery of oocytes by LOPU in common sika deer (Cervus nippon nippon) before transposition of an optimized methodology for IVP of embryos from endangered Vietnamese sika deer hinds (Cervus nippon pseudaxis). In common sika deer, two doses of oFSH (0.25 and 0.5 U) and two frequencies of administration (12 and 24 h) were compared by monitoring of subsequent ovarian response, quality of oocytes recovered by LOPU, and in vitro developmental competence. In a first experiment, the dose of oFSH administered did not significantly affect the total number of follicles aspirated per hind per session (8.6 ± 1.0 vs. 8.2 ± 1.6 with 0.5 vs. 0.25 U oFSH, respectively; not significant). In a second experiment, frequency of 0.25 U oFSH administration did not affect ovarian response. Efficiency of IVP determined on blastocysts rates after in vitro maturation, fertilization, and development in oviduct epithelial cells coculture was increased when FSH was administered at 12-h intervals. Immune response after several follicular stimulations was detected against exogenous oFSH in plasma from the majority of sika deer hinds but was not associated with decreased ovarian response. When 0.25 U oFSH was administered at 12-h intervals to Vietnamese sika deer (N = 4), good quality cumulus oocyte complexes with complete and compact cumulus investments were recovered allowing a high cleavage rate after in vitro maturation and fertilization. Development to the blastocyst stage occurred in a high proportion (30% of oocytes) after coculture with ovine epithelial cells allowing cryobanking of transferable embryos from Vietnamese sika deer. These results confirm that LOPU-IVF after ovarian stimulation with oFSH may be a successful tool for cryobanking transferable embryos from endangered sika deer subspecies.     

Effects of once- versus twice-weekly transvaginal follicular aspiration on bovine oocyte recovery and embryo development

Ultrasound-guided transvaginal follicular aspiration combined with in vitro maturation/in vitro fertilization (IVM/IVF) and culture was used to obtain bovine preimplantation stage embryos. Evaluated were the effects of aspiration frequency on oocyte recovery and embryo development following IVM/IVF. In Experiment 1, transvaginal follicular aspiration was performed once (n=5) or twice (n=5) weekly in multiparous Angus cows with the aid of a transvaginal sector transducer (5-MHz). In Experiment 2, aspiration was performed on Angus cows once weekly (n=6), twice weekly (n=4), or twice weekly after treatment with FSH (15 mg; n=4). Follicles (>2 mm) were punctured using a 55-cm needle (17g), and oocytes were aspirated through the needle and silastic tubing (2 m) by vacuum suction (75 mmHg). The oocytes were examined for morphology and were in vitro matured and fertilized. Following IVF, all ova were co-cultured in vitro for 7 d on Buffalo Rat liver cells. Oocyte recovery rates per asp?ration session in Experiment 1 were not different between groups aspirated once or twice weekly (6.8+/-2.0 vs 6.3+/-1.1 oocytes/session; x+/-SEM) or in Experiment 2 between groups aspirated once, twice, or twice plus FSH treatment (7.7+/-1.8 vs 9.5+/-1.1 vs 6.2+/-1.1; P>0.10). In vitro development to the blastocyst stage was not different between the once, twice or twice-weekly aspiration plus FSH treatments or control oocytes obtained from cows at slaughter (23.1 vs 26.1 vs 18.0 vs 27.9%; P>0.10). Oocytes from the twice-weekly and twice-weekly plus FSH aspiration groups generated a higher percentage of Grade-1 quality embryos than the once-weekly group (P<0.05). In commercial bovine oocyte aspiration, more transferable embryos can be generated from twice-weekly aspirations than from once-weekly aspiration.     

Successful in vitro fertilization of in vivo matured oocytes aspirated laparoscopically from red deer hinds (Cervus elaphus)

Most current protocols of in vitro fertilization in ruminants are based on in vitro maturation of oocytes derived from abattoir material. For application of IVF technology to captive endangered species, however, noninvasive techniques are required which allow repeated collection of oocytes from live females. The aim of this study was to develop a method for embryo production from mature oocytes collected laparoscopically from red deer hinds. Follicular development was synchronized in red deer hinds by the insertion of intravaginal progesterone-releasing devices for 10 d, and ovarian stimulation was induced with 1000 IU, i.m. PMSG 48 h before progesterone device removal. Oocytes were harvested by laparoscopy under xylazine/ketamine sedation 24 h after progesterone device removal and then co-incubated with frozen-thawed red deer spermatozoa for 24 h. In Experiment 1, oocytes and embryos were fixed and stained at different developmental timepoints. Their external morphological changes (cumulus expansion, extrusion of the second polar body and cytokinesis) paralleled their nuclear developmental changes (formation of the 2nd metaphase spindle of meiosis, pronuclear formation and nuclear division, respectively). In Experiment 2, embryos were maintained in vitro until they ceased to undergo cell division. A total of 39 aspiration procedures was carried out on 14 red deer hinds. Forty-four cumulus-oocyte complexes (COC) were aspirated from 95 large Graafian follicles; of these, 27 were classed as mature/nondegenerated on the basis of cumulus/cytoplasmic morphology. Seventeen oocytes cleaved following in vitro fertilization, yielding six 2-cell embryos, six 4-cell embryos, four 8-cell embryos and one 16-cell embryo. The results indicate that laparoscopic aspiration of mature oocytes from hormone-treated females offers a valuable source of genetic material for assisted deer breeding programs.     

Progesterone treatment, FSH plus eCG, GnRH administration, and Day 0 Protocol for MOET programs in sheep

The effect of various superstimulatory treatments on the number of corpora lutea, fertilization rate, and embryo yield was studied in sheep. Overall, data from 708 Merino donors and 4262 embryos were analyzed in four experiments. In Experiment 1, varying intervals of progesterone treatment (5 to 14 d) before follicle-stimulating hormone (FSH) administration did not significantly affect the proportion of responding donors, the mean number of corpora lutea, or the mean number of recovered and transferable embryos per donor. In Experiment 2, a single dose of equine chorionic gonadotropin (eCG, 200 or 300 IU) combined with the FSH treatment (i.e., given at CIDR removal) reduced the number and the quality of embryos compared with that for not giving eCG (P < 0.05). In Experiment 3, one dose of gonadotropin-releasing hormone (GnRH) given 24 h after CIDR removal improved the number of transferable embryos compared with that for not giving GnRH (P < 0.05). In Experiment 4, the new superstimulatory Day 0 Protocol, which includes starting FSH treatment at the emergence of Wave 1 (i.e., soon after ovulation, in the absence of a large follicle), improved ovarian response, with a tendency to produce more embryos compared with that for the Traditional Protocol. In summary, this study, analyzing data from various pharmacologic treatments, allows an improvement from four to eight transferable embryos per treated donor in multiple ovulation and embryo transfer programs in sheep.     

Preovulatory LH profiles of superovulated cows and progesterone concentrations at embryo recovery

Forty-two Holstein cows were randomly assigned to three superovulatory treatment groups of 14 cows each. Cows in Group I received follicle stimulating hormone (FSH; 50 mg i.m.); those in Group II received FSH (50. mg i.m.) along with GnRH (250 ug in 2 % carboxymethylcellulose s.c.) on the day of estrus; and cows in Group III were infused FSH (49 mg) via osmotic pump implants. FSH was administered over a 5-d period for cows in Groups I and II (twice daily in declining doses). Cows in Group III received FSH over a 7-d period (constantly at a rate of 7 mg/day). All cows received 25 mg PGF(2)alpha (prostaglandin F(2)alpha) 48 hours after initiation of the FSH treatment. Blood samples were collected from seven cows from each group at 2 hour intervals on the fifth day of superovulation for serum luteinizing hormone (LH) concentration analysis by radioimmunoassay, and blood samples were collected from all cows on the day of embryo recovery for plasma progesterone determination. The LH profile was not altered (P>0.05) by either GnRH administration or by the constant infusion of FSH as compared to FSH treatment alone. Plasma progesterone concentrations were highly correlated with the number of corpora lutea (CL) palpated (r=0.92; P<0.01) and with the number of ova and/or embryos recovered (r=0.88; P<0.01). The accuracy of predicting the number of recoverable ova and/or embryos by the concentration of plasma progesterone was 86%.     

Superovulation of dairy cows with purified FSH supplemented with defined amounts of LH

This study investigated the effects of a purified follicle stimulating hormone (FSH) preparation supplemented with three different amounts of bovine luteinizing hormone (bLH) and a commercially available FSH with a high LH contamination on superovulatory response, plasma LH and milk progesterone levels in dairy cows. A total of 112 lactating Holstein-Friesian crossbred dairy cows were used for these experiments; the cows were randomly assigned to treatment groups consisting of purified porcine FSH (pFSH) supplemented with bLH. Group 1 was given 0.052 IU LH 40 mg armour units (AU) FSH (n = 6); Group 2 was given 0.069 IU LH (n = 32); Group 3 received 0.423 IU LH (n = 34); while Group 4 cows (n = 36) were superovulated with a commercially available FSH-P((R)). This compound appeared to contain 8.5 IU LH 40 mg AU FSH according to bioassay measurement. All animals received a total of 40 mg AU FSH at a constant dose twice daily over a 4-d period. Levels of milk progesterone and plasma LH were determined during the course of superovulatory treatment. The Group 1 treatment did not reveal multiple follicular growth, and no embryos were obtained. Superovulation of Group 3 cows resulted in significantly (P<0.05) more corpora lutea (CL; 12.6+/-1.1) and fertilized ova (5.1+/-1.3) compared with Groups 2 and 4 (10.1+/-0.9 and 2.6+/-0.6, 9.0+/-0.9 and 2.7+/-0.5, respectively). Due to a high percentage of degenerated embryos (33%) Group 3 yielded only one more transferable embryo than Groups 2 and 4. Among groups, LH levels differed in the period prior to induction of luteolysis and were similar thereafter. The progesterone pattern following FSH LH administration reflected the amount of LH supplementation. Milk progesterone levels on the day prior to embryo collection were correlated to the number of CLs and recovered embryos. It is concluded that under the conditions of our experiment superovulation with 0.423 IU LH 40 mg AU FSH may yield a significantly improved superovulatory response in dairy cows. It is further suggested that LH supplementation exerts its effects mainly on follicular and oocyte maturation during the period prior to luteolysis.     

Successful in vitro culture of early cleavage stage embryos recovered from superovulated red deer (Cervus elaphus)

Three separate embryo culture systems were evaluated for their ability to support development of early cleavage stage red deer (Cervus elaphus ) embryos: ligated sheep oviducts (Treatment A); cervine oviduct epithelial monolayer in TCM 199 + 10% deer serum (Treatment B); synthetic oviduct fluid + 20% human serum at 7% O(2) atmosphere (Treatment Q. In addition, 2 superovulation protocols were compared for their efficacy in producing early cleavage stage embryos. Twenty red deer (2 to 7 yr old) were synchronized in April with intravaginal CIDR devices for 12 d. All animals received a total of 0.4 units of ovine FSH administered in 8 equal doses, 12 h apart, beginning 72 h before removal of CIDR devices. The deer additionally received 200 IU PMSG, either with the first FSH injection (Group 1, n = 10) or with the last FSH injection (Group 2, n = 10). Hinds were placed with fertile stags following withdrawal of CIDR devices. Ova were collected by surgical recovery 63 h post CIDR removal. At the time of collection, animals in Group 2 had a significantly greater mean (+/- SEM) ovulation rate (11.2 +/- 2.4 vs 5.3 +/- 2.4), with more animals responding to treatment (>1 ovulation), than the animals in Group 1 (10/10 vs 4/10). Late in the breeding season (June), 10 additional red deer (Group 3, Experiment 2) were superovulated using the same protocol as for the deer in Group 2, with ova collection advanced by 24 h. Mean (+/- SEM) ovulation rate was 6.4 +/- 1.2 with 9 10 animals responding. Ova recovery did not differ among the groups (range 73 to 87%). Superovulation treatment did not affect cultured embryo development to the morula/blastocyst stage. Furthermore, there was no difference among the 3 culture systems in their support of development either to the morula (range 50 to 58%) or to the blastocyst (range 22 to 26%) stage. After laparoscopic transfer of 4 morula/blastocyst embryos to recipient red deer (2 from Treatment B and 2 from Treatment C) 2 live calves were born from embryos cultured in Treatment B.     

Superovulation of beef heifers with Folltropin: A new FSH preparation containing reduced LH activity

The optimum superovulatory dose of Folltropin was determined and compared with a standard 28 mg dose of FSH-P in beef heifers. In Experiment 1, mean numbers of corpora lutea (CL) did not differ among the groups treated with 10, 20, 30 or 40 mg Folltropin or FSH-P, and the mean CL number was reduced (P<0.05) only in the 5 mg Folltropin group. Mean numbers of ova/embryos recovered, fertilized and transferable were greater (P<0.05) for the 10, 20 and 30 mg Folltropin groups than for the 5 mg group. The 40 mg Folltropin group and the FSH-P group were intermediate. The percentage of fertilized and transferable embryos did not differ over the dosages used in this experiment. In Experiment 2, mean numbers of CL were greater for the 9, 18 and 36 mg Folltropin groups than for the 4.5 mg group, with the 9 mg group being lower than the 36 mg group (P<0.05). The 18 mg group was intermediate and did not differ. Mean numbers of ova/embryos recovered and fertilized ova were greater for the 9, 18 and 36 mg groups (P<0.05) than for the 4.5 mg group. The percent of fertilized and mean number and percentage of transferable embryos did not differ among treatments. We conclude that Folltropin may be a satisfactory superovulatory replacement for FSH-P and that a dose of 18 to 20 mg Folltropin may be within the optimum superovulatory dosage range for beef heifers. Dosages of Folltropin of more than twice the optimum did not result in deterioration of ova/embryo quality.     

Superovulation in the cow with a single intramuscular injection of FSH dissolved in polyvinylpyrrolidone

It is desirable to reduce the number of treatments required to induce superovulation in cows. In this study we examined whether dissolving FSH in polyvinylpyrrolidone(PVP) would reduce the rate of absorption of FSH and allow it to be administered in a single dose for superovulation. In Experiment 1, 10 cows each received a single dose of FSH which contains 0.6% luteinizing hormone (FSH-R; 30mg i.m.) dissolved in 30% PVP (10ml) or in saline. In Experiment 2, a single injection of 30mg FSH-R dissolved in 30% PVP was given to 25 cows, and 32 cows were injected twice daily in declining doses to receive a total of 28mg FSH-R dissolved in saline. Prostaglandin F(2alpha) was given to all the cows 48h after the first FSH treatment. Embryos were collected on Day 7 or 8 post insemination. In Experiment 1, the effect of FSH dissolved in PVP was compared with that dissolved in saline (number of recovered ova and embryos; 9.4+/-4.1 vs. 0). In Experiment 2, the rate of transferable embryos by single injection of FSH-R in PVP were significantly higher (P<0.05) than that of treatment of multiple injection groups. Progesterone concentration measured in serum collected 4 times from estrus (Day-0) to the day of embryo collection, indicated similar patterns in the 2 treatment groups. These findings suggest that PVP is a suitable solvent for prolonging the absorption of FSH given in a single injection thus providing a more practical approach of FSH administration.     

Fertilization rates in superovulating cows after deposition of semen on the infundibulum, near the uterotubal junction or after insemination with high numbers of sperm

Three experiments were conducted with 105 superovulating Holstein dairy cows in attempts to improve the fertilization rate. Cows were superovulated with follicle-stimulating hormone (FSH) and time of estrus was regulated with prostaglandin F(2)alpha (PGF(2)alpha). Semen was deposited on each infundibulum through a laparoscope inserted through the flank (Experiment 1) or near the uterotubal junctions through flexible tubing passed through the cervix and uterine horns (Experiment 2). In the third experiment, high numbers of sperm in fresh semen were deposited in the uterus. Cows were necropsied and ova were recovered and examined about 3.5 d after the beginning of estrus. Deposition of 0.5 ml of frozen-thawed semen on each infundibulum (Experiment 1) reduced both ovum recovery and fertilization. In ten cows inseminated on the infundibulum, ova representing 43% of ovulation points were recovered and 9% of these recovered ova were fertilized. In ten control cows, ova representing 80% of ovulation points were recovered and 62% of them were fertilized. In a 2 x 2 experiment with 36 superovulating cows (Experiment 2), 1 ml of diluted fresh or frozen semen was deposited either near the uterotubal junction or in the uterine body. The overall fertilization rate was 61%, with no significant effect of site of semen deposition or type of semen used. In Experiment 3, 2 or 3 ml of neat semen (average of 4.4 billion sperm) was deposited in the uterus of 12 cows; 183 of 197 intact ova (93%) were fertilized. In 56 control cows inseminated with 0.5 to 1.5 ml of frozen diluted semen (average of 70 million sperm), 502 of 947 intact ova were fertilized (53%, P<0.001). Insemination with high numbers of fresh sperm overcame problems of sperm loss or sperm transport and improved the fertilization rate.     

Serum progesterone changes in luteal cyclicity and duration of estrous cycle in Formosan sika deer (Cervus nippon taiouanus) hinds

A study was conducted to investigate the serum progesterone (SP(4)) profiles and duration of estrous cycles in the farmed Formosan sika deer (FSD; Cervus nippon taiouanus) during the major breeding season. Five parous, open and non-milking hinds were allotted to collect peripheral blood samples twice weekly for P(4) measurement by radioimmunoassay beginning at the initiation of the rutting season indicated by rutting behaviors of the sexually mature stags. The hinds were polyestrous as proved by cyclic changes of SP4 levels. After the presumptive estrus shown by the lowest concentration of SP(4) (0.20+/-0.01 ng/ml), this ovarian hormone markedly elevated on day 7 of the cycle (1.67+/-0.11 ng/ml), reached plateau (3.15+/-0.16 ng/ml, P<0.01) during days 11 to 18, and then declined to the basal levels in the subsequent estrus. It is concluded that mean duration of the estrous cycle in FSD during the major rutting season is 19.3 days with a range of 17 to 21 days, and that the patterns of circulating progesterone profiles during the estrous cycles of the FSD are similar to those of other deer species so far investigated.     

Superstimulation of ovarian follicular development in beef cattle with a single intramuscular injection of Folltropin-V

The need to inject FSH twice daily for superstimulation of ovarian follicular development in cattle necessitates frequent attention by farm-personnel and increases the possibility of failures due to mishandling and errors in administration of treatments. A series of three experiments were designed to evaluate the feasibility of superstimulation in beef cattle with a single intramuscular (IM) injection of Folltropin-V diluted in a hyaluronan-based slow-release formulation (SRF). In Experiment 1, cows were assigned to one of three treatment groups to compare two methods of injection as compared to the twice daily IM injection protocol. Superovulatory response of cows (n=6) treated with twice daily IM injections over 4 days (Control) was greater than of cows treated with a single subcutaneous (SC) injection in SRF (n=6), while superovulatory response of cows treated with a single IM injection in SRF (n=6) was intermediate. Experiment 2 was designed to compare two concentrations of SRF (20mg/mL hyaluronan, 100% compared to 10mg/mL hyaluronan, 50%) in a single IM injection protocol. The mean number of corpora lutea (CL) were not significantly different (P≥0.05), but the numbers of total ova/embryos (P<0.05), fertilized ova (P<0.01) and transferable embryos (P<0.001) were greater in cows treated with FSH in 100% SRF (n=20) than cows treated with FSH in 50% SRF (n=20). Experiment 3 was designed to compare superovulatory response in Red Angus donor cows treated with a single IM injection of Folltropin-V diluted in 100% solution of SRF with those treated with the traditional twice-daily IM injection protocol over 4 days. Mean (±SEM) numbers of CL (13.7±1.2 compared to 13.8±1.2), total ova/embryos (12.3±1.5 compared to 13.7±2.1), fertilized ova (7.2±1.1 compared to 8.4±1.4) and transferable embryos (4.9±0.8 compared to 6.4±1.3) were not significantly different between Control (n=29) and Single injection (n=29) groups, respectively. In summary, superstimulation of beef donor cows with a single IM injection of Folltropin-V diluted in 100% solution of SRF resulted in a comparable superovulatory response to the traditional twice-daily IM administration of Folltropin-V diluted in saline over 4 days.     

Induction of ovarian follicular wave emergence in wapiti (Cervus elaphus)

Two experiments were done to test the effects of treatments designed to electively induce ovarian follicular wave emergence in wapiti for the purpose of group synchronization. In Experiment 1, hinds were assigned randomly to three groups and given saline im (controls; n=5), 5mg of estadiol-17ss im (n=4), or 5mg estradiol-17ss plus 100mg progesterone im (n=5). In Experiment 2, hinds were assigned randomly to two groups and given no treatment (controls; n=6), or transvaginal ultrasound-guided follicle ablation (n=7). In both experiments, ovarian follicular dynamics were monitored by daily transrectal ultrasonography from Day 0 (day of treatment) to Day 9. In Experiment 1, blood samples were collected at each examination for measurement of serum concentrations of progesterone and FSH. Both experiments were conducted during the late anestrous period (July and August). The mean (+/-S.E.M.) day of wave emergence did not differ between the control and estradiol alone groups, but tended to be later in the estradiol plus progesterone group Day 4.0+/-0.7, Day 3.5+/-0.3, and Day 5.2+/-0.2, respectively; P=0.06). The interval from treatment to wave emergence was less variable in the estradiol plus progesterone group (P<0.05) and tended to be less variable in the estradiol-alone group (P=0.07) than in the control group. The day of wave emergence was more variable (P<0.05) and tended to be later (P=0.10) in the control group compared to the ablation group (Day 2.5+/-0.8 versus Day 1.4+/-0.2). All three treatments were effective in synchronizing ovarian follicular wave emergence among a group of wapiti hinds. Follicle ablation may be an alternative method for synchronization of follicular waves in estrus synchronization and superstimulatory protocols.     

Relationship of sperm migration in anterior vaginal fluid and embryo quality in superovulated dairy heifers

Anterior vaginal fluid samples from 26 superovulated dairy heifers at insemination were classified into 2 grades: 1) with abnormal sperm penetration ability when vanguard sperm migration was randomly oriented; and 2) with normal sperm penetration ability when vanguard sperm migration was parallel and unidirectional. Vanguard sperm behavior and vanguard sperm migration distances were evaluated for their effects on fertilized ova recovery rates and transferable embryo recovery rates. Twelve vaginal fluid samples (46%) showed abnormal sperm penetration ability (Grade 1) and the mean +/- sem distance traveled by the vanguard spermatozoa into these samples (7.3 +/- 0.9 mm) was different (P<0.0001) from the remainder of the samples (48 +/- 3.4 mm) in which sperm penetration was registered as normal (Grade 2). In heifers in which anterior vaginal fluid samples were Grades 1 and 2, the fertilized ova recovery rates were 78.3% and 80.2%, respectively (P=0.91). Transferable embryo recovery rates were 54.2% and 32% for Grades 1 and 2, respectively (P<0.001). Using correlation and linear regression analysis, the sperm migration distance in Grade-2 samples was not related to fertilized ova (P=0.77) or to transferable embryo recovery rates (P=0.97). These results indicate that vanguard sperm movement into capillary tubes varied qualitatively and was related to subsequent embryo quality.     

Superovulation induction in Japanese Black cattle by a single intramuscular injection of hMG or FSH dissolved in polyvinylpyrrolidone.

The efficacy of a single intramuscular dose of 450 or 600 international units (IU) of human menopausal gonadotropin (hMG) or 30 mg of follicle stimulating hormone (FSH), each dissolved in 30% polyvinylpyrrolidone K-30 (PVP), for superovulation treatment was compared to that of superovulation induction by administration of a total dose of 600 IU hMG given in declining doses twice daily over a 3-day period. A total of 48 Japanese Black cows were used for the investigation. Oestrus was observed within 60 h after PGF2alpha administration in all cows in the hMG groups. In the hMG group that received a single dose of 600 IU hMG (n = 12), oestrus was observed less than 36 h after treatment in one cow. In contrast, oestrus was not observed in 3 of the 12 cows (25%) in the FSH group. Neither the average number of recovered ova/embryos nor the number of transferable embryos per collection differed significantly among the hMG groups. However, the average number of transferable embryos was not significantly higher in cows treated with a single dose of 600 IU of hMG than in cows treated with a single 30 mg dose of FSH (7.5+/-4.5 vs. 2.1+/-2.8). The number of cows from which more than three excellent grade embryos were collected was highest in the group that received a single dose of 600 IU hMG (9/12, 75%) and lowest in the group that received a single 30 mg dose of FSH (2/9, 22%). The differences between groups in the percentages of cows with three or more excellent embryos between treatments were not statistically significant. The proportion of recovered ova/embryos classified as excellent was highest in the group that received 600 IU hMG in declining doses and lowest in the group that received a single 30 mg dose of FSH (55.2% vs. 30.2%; P < 0.05). The recovery rate of unfertilized ova was lowest in the group that received a single dose of 600 IU hMG and highest in the group received a single 30 mg dose of FSH (18.3% vs. 48.8%; P < 0.05). Although the differences in recovery results between the groups were not statistically significant, the recovery rates in hMG groups were higher than that the FSH group. These findings suggest that superovulation can be induced adequately in Japanese Black cows using one injection of 450 to 600 IU hMG dissolved in PVP.     

Estrus synchronization with an oral progestogen prior to superovulation of postpartum beef cows

Ovarian follicular dynamics and steroid secretion patterns were monitored in postpartum beef cows that were synchronized for estrus with melengestrol acetate (MGA) or prostaglandin F(2alpha) (PGF) prior to superovulation. Twenty-four muhiparous Angus cows were stratified by number of days postpartum to an MGA or PGF treatment prior to superovulation. Cows in the MGA group were fed 0.5 mg MGA/d for 14 d in a grain carrier. Superstitnulatory treatments began 14 d after withdrawal of MGA from feed or 11 d after administering a single injection of 500 microg cloprostenol (PGF). Supersthnulatory treatments (FSH) were administered twice daily in decreasing doses (7.5, 5, 5, 2.5 mg) over 4 d. Sixty and 72 h after initiating the superstimulatory treatments, all cows were treated with 750 microg and 500 microg PGF, respectively Cows were inseminated at 0, 12, and 24 h from the onset of standing estrus with semen from 2 proven sires. Cows within treatment were inseminated with 1, 2 and 1 (single) or 2, 4 and 2 units (double) of semen at the designated insemination times. Blood sampling and transrectal ultrasonography of ovaries were performed daily beginning 2 d prior to the initiation of FSH treatment and were continued through embryo recovery. Ovaries were examined daily to determine the number and size of follicles. Plasma samples were analyzed for progesterone and estradiol. Follicles were counted and categorized based on a 5 to 9 mm range or >/= 10 mm. At the end of superovulatory treatment there were more (P /= 10 mm among cows that were estrus synchronized with MGA (75 +/- 1.2) than with PGF (3.9 +/- 1.2) These differences were reflected in higher (P 相似文献   

Superovulatory response to a single subcutaneous injection of Folltropin-V in beef cattle

A series of 4 experiments were designed to evaluate the feasibility of superstimulation in beef cattle with a single sc injection of the porcine pituitary extract, Folltropin-V. In the preliminary study (Experiment 1), superovulatory response of cows (n=7) treated with a single sc injection of 400 mg NIH-FSH-P1 Folltropin-V was not different than that of cows (n=8) superstimulated with twice daily im injections over 4 d, or a single sc injection plus an injection of eCG (n=12). Experiments 2 and 3 were designed to determine the optimal site of a single sc injection. In Experiment 2, cows (n=25) with body condition scores (BCS) of 1 to 2 were used. The mean number of CL counted and ova/embryos collected was lower (P<0.05) in cows treated with the single sc injection in the neck region than in cows treated with a single sc injection behind the shoulder, or with the twice daily im injection treatment. In Experiment 3, cows (n=49) with BCS of 3 to 5 were used. There were no differences in the number of CL, total ova/embrvos collected, fertilized ova and transferable embryos whether treatments were given in the neck region or behind the shoulder, or whether the cows were implanted or not implanted with Syncro-Mate-B. Experiment 4 was designed to determine the optimal superstimulatory dosage of Folltropin-V administered by a single sc injection. Superovulatory response of cows treated with the higher doses (400 mg, 600 mg or 800 mg NIH-FSH-P1) was higher (P<0.05) than those treated with 200 mg NIH-FSH-P1. The number of unovulated (>/=10 mm) follicles at the time of ova/embryo collection was higher (P<0.05) in the 600 and 800 mg groups, and progesterone concentration at estrus was higher (P<0.05) in cows treated with 800 mg than with 400 or 200 mg. It was concluded that a single, bolus sc injection of 400 mg NIH-FSH-P1 of Folltropin-V is as efficacious as the 4-d, twice daily im treatment protocol for inducing superovulation in beef cows. The amount of subcutaneous fat and site of injection appeared to affect the efficacy of a single sc injection; a single bolus sc injection of Folltropin-V behind the shoulder resulted in the most predictable superovulatory response.