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PubMed1991

Cryopreservation of the occasionally improved semen samples for intrauterine insemination: a new approach in the treatment of idiopathic male infertility.

OBJECTIVE: To assess the value of treating idiopathic male infertility by intrauterine insemination (IUI) of the occasionally improved cryopreserved semen. DESIGN: Two groups of idiopathic oligospermic patients were chosen at random and treated by IUI using processed fresh semen in group A and the best available cryopreserved semen samples pooled with fresh samples in group B. SETTING: Egyptian IVF-ET Centre, Maadi, CAiro, Egypt. PATIENTS, PARTICIPANTS: One hundred fifty infertile couples because of idiopathic oligoasthenospermia. INTERVENTION: Intrauterine insemination. MAIN OUTCOME MEASURE: The pregnancy rate was evaluated after an average of three treatment cycles. RESULTS: The pregnancy rate (PR) was significantly higher in group B when compared with group A. The improvement in the PR was highly significant in the subgroup of patients for whom reasonable semen samples could be collected and cryopreserved. CONCLUSIONS: Our study indicates that IUI with fresh semen pooled with cryopreserved occasionally improved semen samples for the treatment of oligoasthenospermia results in an improved PR.

Cryopreservation↗
PubMed1992

Intrauterine insemination after ovarian stimulation as a treatment for subfertility because of subnormal semen: a prospective randomized controlled trial.

OBJECTIVE: To determine whether intrauterine insemination (IUI) after ovarian stimulation with human menopausal gonadotropin (hMG) gives a better pregnancy rate (PR) than natural intercourse in couples with subfertility because of subnormal semen. DESIGN: Prospective randomized controlled trial. SETTING: University based subfertility clinic. PATIENTS: Couples with subnormal semen as the only identifiable cause of subfertility. INTERVENTIONS: In control cycles, the couples had natural intercourse. In IUI cycles, IUI was performed after ovarian stimulation with hMG and human chorionic gonadotropin. MAIN OUTCOME MEASURE: The clinical PRs and complications of IUI cycles and control cycles were compared. RESULTS: There were six clinical pregnancies in the 42 IUI cycles, whereas there was no clinical pregnancy in the 42 control cycles. The clinical PR in IUI cycles (14.3% per cycle) was significantly higher than that in control cycles (0%). Six patients (14.3%) developed moderate degree of ovarian hyperstimulation syndrome in IUI cycles. CONCLUSION: Intrauterine insemination after ovarian stimulation with hMG is useful in treatment of subfertile couples with subnormal semen.

Adult↗
PubMed1994

Does increasing frequency of intrauterine insemination improve pregnancy rates significantly during superovulation cycles?

OBJECTIVE: To compare pregnancy rates (PR) per treatment cycle of controlled ovarian hyperstimulation (COH) patients receiving a single IUI with COH patients receiving two IUIs. DESIGN: A prospective randomized trial of consecutively treated patients attending our infertility clinic for COH and IUI. METHODS: Patients undergoing COH by hMG and hCG were randomized to receive either one (group A) or two (group B) IUIs. Randomization was performed using a random number table. Group A IUIs were timed 35 hours after ovulatory hCG, whereas group B IUIs were performed 19 and 43 hours after hCG. RESULTS: A total of 120 patients during 169 cycles were randomized between group A (90 cycles) and group B (79 cycles). Data analysis demonstrated no significant differences between groups A and B with respect to age, indications for COH, duration of hMG treatment, total amount of hMG administered, peak E2 levels, number of dominant follicles recruited, or mean number of total motile sperm inseminated. Pregnancy rates for groups A and B were 0.11 and 0.14, respectively. The size of our study population permits a conclusion that a 300%, 200%, or 100% difference in PR between the two groups does not exist (power 0.97, 0.80, or 0.61, respectively). CONCLUSION: Among patients undergoing COH and IUI, increasing the frequency of insemination does not provide a significant increase in cycle pregnancy rate.

Chorionic Gonadotropin↗
PubMed1994

Intrauterine insemination with frozen donor sperm: a prospective randomized trial comparing three different sperm preparation techniques.

OBJECTIVE: To compare the pregnancy rates (PRs) after intrauterine insemination (IUI) with frozen-thawed donor sperm. Sperm were isolated after thawing using three different sperm preparation techniques: simple washing, Percoll density gradient, and Sephadex columns (SpermPrep Column; Fertility Technologies, Natick, MA). DESIGN: Women (n = 98) were randomized upon entry into the program into one of three different sperm preparation methods. The same sperm preparation technique was used for the woman during subsequent cycles, if pregnancy did not occur. The study was stopped when > or = 75 treatment cycles for each group were completed for analysis of PRs per treatment cycle. SETTING: All patients were treated at our private care center at the University of Texas Southwestern Medical Center. PATIENTS: Patients entering this study were spontaneously ovulating women undergoing IUI with frozen donor sperm. MAIN OUTCOME MEASURE: Pregnancy rate per cycle of timed IUI. RESULTS: After 260 cycles of insemination, the PR per cycle was 19.1% with simple washing, 16.9% with Sephadex columns, and 11.4% with Percoll density gradient. Although these results were not statistically different, Percoll density gradient had a 40% lower PR per treatment cycle compared with simple washing. However, Percoll density gradient preparation of sperm resulted in a statistically significant increase in the motility, curvilinear velocity, straight line velocity, and the number of normal heads compared with the other two treatments. CONCLUSION: Although Percoll density gradient separation of sperm results in a population of cells that is more motile and morphologically normal, this did not result in subsequent cycle fecundity. These data suggest that the reliance on the averaged values of motility, curvilinear velocity, straight line velocity and morphology may have little predictive value of the potential fertility of frozen-thawed sperm.

Adult↗
PubMed1998

The effectiveness of intrauterine insemination in couples with sterility due to male infertility with and without a woman's hormone factor.

OBJECTIVE: To examine the efficacy of IUI on fecundity and baby-take-home rates in cases of infertility attributable to a male factor with and without a woman's hormone factor. DESIGN: Retrospective analysis. SETTING: Department of Gynecology and Obstetrics at the General Public Hospital, Horn, Austria. PATIENT(S): Seventy-eight long-standing involuntarily childless couples. INTERVENTION(S): After a follicular phase GnRH analog (buserelin) protocol with hMG stimulation of the woman and a Percoll gradient preparation and capacitation of the man's semen, an IUI was performed. MAIN OUTCOME MEASURE(S): Fecundity and baby-take-home rates. RESULT(S): One hundred nine inseminations were followed by 53 pregnancies (48.6%; 95% confidence intervals (CI) 38.9%-58.4%) and 38 deliveries (34.9%; 95% CI 26.0%-44.6%). Forty-nine children were born and 47 are alive (43.1%). CONCLUSION(S): Intrauterine insemination combined with buserelin gonadotropin stimulation, Percoll semen preparation, and sperm capacitation is a feasible solution to the problem of sterility attributable to a male factor with and without a woman's hormone factor.

Adolescent↗
PubMed1999

Advanced semen analysis: a simple screening test to predict intrauterine insemination success.

OBJECTIVE: To determine if a simple screening test of sperm recovery through a density gradient preparation and sperm survival after a 24-hour incubation is predictive of IUI success. DESIGN: Prospective nonrandomized descriptive study. SETTING: Tertiary assisted reproductive technology center. PATIENT(S): Four hundred fourteen couples undergoing IUI for male factor and unexplained infertility. INTERVENTION(S): An advanced semen analysis, which consisted of a basic semen analysis, sperm processing through a density gradient preparation, and a 24-hour sperm incubation, was performed on all couples before beginning IUIs. MAIN OUTCOME MEASURE(S): Cumulative and per cycle pregnancy rates (PRs) were calculated for routine semen parameters, number of sperm processed through density gradient, and percent motile sperm after a 24-hour incubation. RESULT(S): None of the basic semen analysis parameters accurately predicted IUI success. When the processed total motile sperm available for insemination was > or = 10 x 10(6) and their 24-hour survival was > or = 70%, 89% (162 of 182) of couples achieved a pregnancy with a 21.4% (162 of 757) per cycle PR compared to a 2.8% (11 of 403) per cycle PR and 4.7% total PR when survival was <70%. With use of these cutoff values for the advanced semen analysis, the test had a sensitivity of 94% and specificity of 86%. CONCLUSION(S): The number of motile sperm available for insemination and especially their 24-hour survival are highly predictive of IUI success. This advanced semen analysis is an excellent screening test to evaluate couples considering IUI.

Cell Survival↗
PubMed1999

Comparison of the sperm quality necessary for successful intrauterine insemination with World Health Organization threshold values for normal sperm.

OBJECTIVE: To compare World Health Organization threshold values for normal sperm with the initial sperm quality necessary for successful IUI. DESIGN: Retrospective study. SETTING: Private fertility clinic. PATIENT(S): One thousand eight hundred forty-one couples undergoing 4,056 cycles of IUI. INTERVENTION(S): Intrauterine insemination. MAIN OUTCOME MEASURE(S): Relation of initial sperm quality to fecundity. RESULT(S): Progressive motility and total motile sperm count were the initial sperm characteristics most closely related to pregnancy on discriminant analysis. The per-cycle pregnancy rate averaged 11.1% during the first three IUI cycles. Pregnancy rates were > or = 8.2% per cycle when the initial sperm values were a concentration of > or = 5 X 10(6)/mL, a total count of > or = 10 X 10(6), progressive motility of > or = 30%, or a total motile sperm count of > or = 5 x 10(6). Minimal increases in fecundity occurred when initial values were greater than these threshold levels. The lowest initial values that resulted in pregnancy were a concentration of 2 x 10(6)/mL, a total count of 5 x 10(6). motility of 17%, and a total motile sperm count of 1.6 X 10(6). Pregnancy rates were <3.6% when initial values were between the threshold levels and the lowest levels. CONCLUSION(S): The sperm quality that is necessary for successful IUI is lower than World Health Organization threshold values for normal sperm. Intrauterine insemination is effective therapy for male factor infertility when initial sperm motility is > or = 30% and the total motile sperm count is > or = 5 X 10(6). When initial values are lower, IUI has little chance of success.

Adult↗
PubMed1999

Efficacy of double intrauterine insemination in controlled ovarian hyperstimulation cycles.

OBJECTIVE: To investigate the effectiveness of double IUI and to determine the optimal timing of IUI in relation to hCG administration. DESIGN: Prospective randomized study. SETTING: Infertility Center, Department of Obstetrics and Gynecology, University of Milan. PATIENT(S): Patients with male factor and unexplained infertility undergoing controlled ovarian hyperstimulation (COH) and IUI. INTERVENTION(S): After COH with clomiphene citrate and gonadotropins, patients were randomly assigned to one of the following groups: group A received a single IUI 34 hours after hCG administration, group B received a double IUI 12 hours and 34 hours after hCG administration, and group C received a double IUI 34 hours and 60 hours after hCG administration. MAIN OUTCOME MEASURE(S): Number of follicles > 15 mm in diameter on the day of hCG administration, number of motile spermatozoa inseminated, clinical pregnancy rate. RESULT(S): Two hundred seventy-three patients underwent 449 treatment cycles: 90 patients were treated for 156 cycles in group A, 92 patients for 144 cycles in group B, and 91 patients for 149 cycles in group C. The overall pregnancies rates for groups A, B, and C were 13 (14.4% per patient and 8.3% per cycle), 28 (30.4% per patient and 19.4% per cycle), and 10 (10.9% per patient and 6.7% per cycle), respectively. There was a statistically significant difference between group B and groups A and C. CONCLUSION(S): Our data indicate that two IUIs performed 12 hours and 34 hours after hCG administration is the most cost-effective regimen for women undergoing COH cycles with clomiphene citrate and gonadotropins. Although the second insemination adds up to a slightly higher cost, it significantly increases the chance of pregnancy.

Adult↗
PubMed2002

Processed total motile sperm count correlates with pregnancy outcome after intrauterine insemination.

OBJECTIVES: To determine the impact of processed total motile sperm (PTMS) count on pregnancy after partner intrauterine insemination (IUI). IUI is generally attempted before proceeding to more expensive and invasive assisted-reproductive techniques such as intracytoplasmic sperm injection. Several semen parameters have been shown to correlate with IUI outcome and may be useful when counseling couples. METHODS: Four hundred thirty-eight couples with diverse causes of infertility underwent 1114 cycles of husband IUI during a 39-month period. The clinical and semen parameters were recorded for each couple and each insemination. The parameters were compared between those couples who achieved a pregnancy and those who did not. RESULTS: The total number of pregnancies was 120, resulting in a pregnancy rate per cycle of 10.8% and a couple pregnancy rate of 27.4%. On multivariable logistic regression analysis, the PTMS count was independently associated with fertility after IUI (P = 0.0014). Moreover, the pregnancy rate was significantly lower for couples with less than 10 million PTMS (P <0.05). CONCLUSIONS: The results of this study have demonstrated that the PTMS count independently predicts success with IUI. Cycles with less than 10 million total motile sperm are significantly less likely to result in a pregnancy. If cause-specific therapy has failed, alternatives to IUI should be considered for couples when the PTMS count is less than 10 million.

Adult↗
PubMed2000

Induction of follicular wave emergence for estrus synchronization and artificial insemination in heifers.

The objective was to synchronize follicular wave emergence among cattle for synchronization of estrus and ovulation, and to determine pregnancy rate after AI at observed estrus. At random stages of the estrous cycle, a controlled internal drug release device (CIDR-B) was inserted intravaginally (Day 0) in 67 cross-bred beef heifers, and they were randomly allocated to receive either no further treatment (Control; n = 18); 5 mg of estradiol-17beta and 100 mg of progesterone im (E/P; n = 16); 100 microg im of GnRH (GnRH; n = 16); or transvaginal ultrasound-guided follicular ablation of all follicles > or = 5 mm (FA; n = 17). All heifers received a luteolytic dose of PGF (repeated 12 h later), and CIDR-B were removed on Days 9, 8, 6 or 5, in Control, E/P, GnRH or FA groups, respectively, so the dominant follicle of the induced wave was exposed to exogenous progesterone for a similar period of time in each group. Mean (+/- SEM) intervals (and range, in days) from treatment to follicular wave emergence in these groups were 3.5 +/- 0.6 (-2 to 8), 3.4 +/- 0.1 (3 to 4), 1.5 +/- 0.3 (-1 to 4), and 1.0 +/- 0.1 (0 to 2), respectively. Although the interval was longest (P<0.01) in the E/P and Control groups, it was least variable (P<0.01) in the E/P and FA groups. Intervals (and range, in days) from CIDR-B removal (and first PGF treatment) to estrus were 2.3 +/- 0.2 (1.5 to 4.5), 2.2 +/- 0.2 (1.5 to 3.0), 2.1 +/- 0.1,(1.5 to 3.5), and 2.5 +/- 0.1 (2.0 to 3.5), and to ovulation were 3.5 +/- 0.2 (2.5 to 5.5), 3.4 +/- 0.1 (3.0 to 4.5), 3.5 +/- 0.1 (2.5 to 4.5), and 3.8 +/- 0.1 (3.0 to 4.5), for Control, E/P, GnRH and FA groups, respectively (ns). The proportion of heifers displaying estrus was higher in the Control than in the FA group (94% versus 65%, P<0.05) and intermediate in EP and GnRH groups (87% and 75%). Heifers were inseminated approximately 12 h prior to ovulation (based on estrous behavior and ultrasound examinations). Pregnancy rates were 78%, 80%, 69% and 65% for Control, E/P, GnRH and FA groups, respectively (P=0.73). Results support the hypothesis that synchronous follicular wave emergence results in synchronous follicle development and, following progesterone removal, synchronous estrus and ovulation with high pregnancy rates to AI. The synchrony of estrus and ovulation in the E/P, GnRH and FA groups suggest that these treatments, in combination with CIDR-B, could be adapted to fixed-time insemination programs.

Animals↗
PubMed2000

A meta-analysis of studies of the effect of GnRH 11-14 days after insemination on pregnancy rates in cattle.

A number of studies have used GnRH between 11 and 14 days after insemination to improve pregnancy rates in cows, however published results have not been consistent. We wished to investigate whether a consolidated estimate of the response could be quantified. Therefore we conducted a meta-analysis of the available data, 19 studies from 14 published papers, on the effect of GnRH analogs on pregnancy rate when given between Days 11 and 14 after first insemination. Odds ratios (the relative probability of pregnancy between treated and control cows) were compared for each study and found to vary significantly among studies, ranging from 0 to 22%. We showed by logistic regression analysis that response to GnRH treatment varied with cow type (beef or dairy), age (cow or heifer), estrus synchronization (synchronized or natural), pregnancy diagnosis (method and time) and effect of individual study. When all these variables were included only 6 of 14 publications could be analyzed, representing 2,541 instead of 10,945 cows. In this limited subgroup of data, a significant improvement in pregnancy rate was detected among treated cattle (odds ratio = 1.33; P<0.01).

Animals↗
PubMed2001

Fertilization and embryo recovery rates in superovulated chios ewes after laparoscopic intrauterine insemination.

Forty superovulated dairy ewes of the Greek Chios breed were used in an experiment to evaluate the efficiency of laparoscopic intrauterine insemination on fertilization and embryo recovery rates as well as embryo quality. Estrus was synchronized by intravaginal progestagen impregnated sponges and superovulation was induced by administration of 8.8 mg o-FSH i.m. following a standard 8 dose protocol. A small volume (0.3 mL) of diluted fresh ram semen was deposited in each uterine horn 24 to 28 h after onset of the estrus by a laparoscopic technique. The animals were allocated randomly into two groups (Group A and B) of 20 animals each. In Group A, embryos were recovered 18 to 24 h after the intrauterine insemination and in Group B on Day 6. The average number of corpora lutea was 12.8 +/- 1.2 and 11.5 +/- 1.1 (+/- SEM); the overall embryo recovery was 66.4% and 57% and the percentage of recovered fertilized ova was 81% and 82.8% in Groups A and B, respectively. More fertilized ova were collected per ewe from Group A (P < or = 0.1). Results indicated that in Chios breed, superovulation using homologous FSH combined with laparoscopic AI leads to good ovarian response with satisfactory results in fertilization, embryo recovery and quality of embryos. This could lead to improved and more efficient methods for obtaining large numbers of high quality oocytes and embryos for embryo transfer programs which could contribute to genetic improvement and increase of the population size.

Animals↗
PubMed2001

Reproductive performance of postpartum dairy cows under a highly intervenient breeding program involving timed insemination and combinations of GnRH, prostaglandin F2alpha and human chorionic gonadotropin.

Lactating Holstein cows (n=288) were grouped as pairs at parturition and randomly assigned to two treatments (control, C vs intervenient treatment, T). The reproductive management of the Group C cows (n=130) consisted of the intramuscular administration of 500 microg PGF2alpha analogue (PG) on Days 28 and 63 postpartum and breeding on the basis of estrus signs with the a.m.-p.m. rule after Day 63. Cows that were not bred by 77 d postpartum received another injection of PG and were bred at estrus or 84 h after PG treatment. Pregnancy diagnoses were perfomed by palpation of the uterus per rectum 42 to 48 d after AI. Cows in the T group (n=139) received intramuscular injections of 100 microg GnRH 14 d and PG 28 d after calving. On Day 56 postpartum, cows were given a second dose of GnRH followed by PG on Day 63 postpartum and a third GnRH injection 48 h after PG (OvSynch). Cows were inseminated at a fixed time (22+/-1 h) after GnRH. Five days after the fixed-time insemination cows were given 1500 IU hCG i.m.. Group C and T cows that returned to service or were diagnosed as non-pregnant continued to receive PG at intervals of 14 d with breeding at estrus or 84 h after the second PGF2alpha dose. A sustained increase in milk progesterone concentration was observed in 59.0% of T cows after GnRH administration on Day 14. A similar rise in milk progesterone concentrations was observed in 53.8% of C cows. The PG on Day 28 induced luteolysis more in Group T cows (53.2%) than in Group C cows (36.9%). The PG on Day 63 reduced milk progesterone concentrations to basal levels in 50.7% of T and 49.2% of Group C animals. The first service pregnancy rates (T, 40.3% vs C, 36.2%) and the overall pregnancy rates (all services, T, 83.5% vs C, 86.9%) were not different between the two groups. The two treatments did not differ in the interval from first service to pregnancy, calving to pregnancy or in calving interval, number of services per pregnancy or culling rates.

Animals↗
PubMed2001

State of the art in artificial insemination of pigs in the United States.

Currently, the United States ranks second in pork production worldwide. In 1999 the breeding herd consisted of approximately 6.2 million breeding females with an annual production of 100 million market animals having an average market live weight of 118.6 kg. The objective of this paper is to briefly describe the current US swine artificial insemination (AI) industry and to profile semen production and insemination practices that are currently in use.

Animals↗
PubMed2002

Influence of centrifugation or low extension rates prefreezing on the fertility of ram semen after cervical insemination.

We compared the fertility of thawed ram semen, frozen according to different prefreezing semen handling protocols and previously well-defined in vitro, after cervical artificial insemination (AI) during natural estrus in Corriedale sheep. Following primary extension 1 + 1, we adjusted the final sperm concentration before packaging (200 x 10(6)/straw) either by centrifugation, in order to reconcentrate the extended semen (Protocol 1: P1), or without centrifugation, by adjusting the final sperm number by stepwise extension (Protocol 2: P2). We evaluated sperm motility (assessed both subjectively and with a computer-assisted sperm analysis instrument [CASA]), membrane integrity (SYBR-14/PI), and capacitation status (chlortetracycline [CTC]) in vitro in three pooled straws of frozen-thawed semen. Three hundred Corriedale ewes, having shown spontaneous estrus during the breeding season (i.e., April, in the southern hemisphere) under extensive management conditions in Uruguay, were cervically inseminated with thawed semen from the same freezing operations as studied in vitro. The semen evaluation in vitro yielded higher percentages (P < 0.05) of damaged spermatozoa in the samples where sperm numbers were adjusted by extension before freezing (P2), compared with when adjustment was done by centrifugation (P1). However, due to the higher sperm concentration finally achieved by P2, the calculated total number of viable spermatozoa was almost equal in the two AI doses. We observed no differences in fertility between P1 and P2 for either nonreturn rates (NRRs) 21 (30.8 vs. 29.7%) and 36 (28.5 vs. 27.8%) days after AI or lambing rate (21.9 vs. 21.4%), respectively. Fertility did not differ significantly between the two different procedures of adjusting sperm numbers prior to freezing. This may indicate that the simplified protocol with adjusted extension of the semen, resulting in higher numbers of viable spermatozoa, should be the procedure of choice when freezing ram semen under field conditions. Further studies aimed at improving the modified protocol need to be performed.

Animals↗
PubMed2002

Embryo recovery and pregnancy rates after the delay of ovulation and fixed time insemination in superstimulated beef cows.

The aim of this study was to evaluate the effect of delaying ovulation subsequent to superstimulation of follicular growth in beef cows (Bos indicus) on embryo recovery rates and the capacity of embryos to establish pregnancies. Ovulation was delayed by three treatments using either progesterone (CIDR-B) or a GnRH agonist (deslorelin). Multiparous Nelore cows (n = 24) received three of four superstimulation treatments in an incomplete block design (n = 18 per group). Cows in Groups CTRL, P48 and P60 were treated with a CIDR-B device plus estradiol benzoate (EB, 4 mg, i.m.) on Day-5, while cows in Group D60 were implanted with deslorelin on Day-7. Cows were superstimulated with FSH (Folltropin-V, 200 mg), from Day 0 to 3, using twice daily injections in decreasing amounts. All cows were treated with a luteolytic dose of prostaglandin on Day 2 (08:00 h). CIDR-B devices were removed as follows: Group CTRL, Day 2 (20:00 h); Group P48, Day 4 (08:00 h); Group P60, Day 4 (20:00 h). Cows in Group CTRL were inseminated at 10, 20 and 30 h after first detected estrus. Ovulation was induced for cows in Group P48 (Day 4, 08:00 h) and Groups P60 and D60 (Day 4, 20:00 h) by injection of LH (Lutropin, 25 mg, i.m.), and these cows were inseminated 10 and 20 h after treatment with LH. Embryos were recovered on Days 11 or 12, graded and transferred to synchronized recipients. Pregnancies were determined by ultrasonography around Day 100. Data were analyzed by mixed procedure, Kruskal-Wallis and Chi-square tests. The number of ova/embryos, transferable embryos (mean +/- SEM) and pregnancy rates (%) were as follows, respectively: Group CTRL (10.8+/-1.8, 6.1+/-1.3, 51.5), P48 (12.6+/-1.9, 7.1+/-1.0, 52.3), P60 (10.5+/-1.6, 5.7+/-1.3, 40.0) and D60 (10.3+/-1.7, 5.0+/-1.2, 50.0). There were no significant differences among the groups (P > 0.05). It was concluded that fixed time AI in association with induced ovulation did not influence embryo recovery. Furthermore, pregnancy rates in embryos recovered from cows with delayed ovulation were similar to those in embryos obtained from cows treated with a conventional superstimulation protocol.

Animals↗
PubMed2003

Fixed-time insemination in peripuberal, lightweight replacement beef heifers after estrus synchronization with PGF2alpha and GnRH.

Estrus synchronization contributes to optimizing the use of time, labor, and financial resources by shortening the calving season, in addition to increasing the uniformity of the calf crop. We determined whether acceptable pregnancy rates could be achieved after synchronization of ovulation and fixed-time artificial insemination (AI) in peripuberal replacement beef heifers using gonadotropin-releasing hormone (GnRH) and PGF2alpha. Crossbred heifers from two herds (MH, n=239; SS, n=330) were wintered at a single location. After a prebreeding examination revealed that 55 heifers had a reproductive tract score (RTS) of 1 (infantile reproductive tracts), they were culled and the remaining heifers were assigned randomly to one of three treatment groups: administration of 25mg PGF2alpha i.m. on Days -12 and 0 followed by estrus detection and insemination between 10 and 14 h after an observed estrus (Control; n=173); administration of 100 microg GnRH i.m. on Day -6, followed by 25 mg PGF2alpha i.m. on Day 0, then fixed-time AI and administration of 100 microg GnRH i.m. on Day +2 (GPG; n=172); and, treatment as for group GPG in addition to administration of 100 microg GnRH i.m. on Day -12 (GGPG; n=169). Bulls were introduced 10 days after AI for 60 days to breed heifers which did not conceive after AI (clean-up bulls). On Days -12, -6, and 0 transrectal ultrasonography was used to monitor ovarian structures in a subset of heifers (30 per treatment). At 30-35 days after AI, ultrasound was used to determine the presence of a viable fetus. Presence of a fetus and stage of pregnancy were determined via palpation per rectum 61-63 days after the conclusion of the breeding season. Heifers in the MH herd (309+/-1.9 kg) were heavier (P<0.001) than those in the SS herd (283+/-1.7 kg) at initiation of the breeding season. Synchronized pregnancy rates were greater (P<0.05) in GGPG (25.4%) and GPG (22.1%) than Control (12.7%) heifers. Pregnancy rates were 9, 21, 32, or 31% for heifers with RTS of 2, 3, 4, or 5, respectively. The average diameter of 22 follicles induced to ovulate in heifers treated with GnRH (GPG and GGPG treatments) was 14.2+/-0.8 mm (range=10.0-23.6 mm). In conclusion, a fixed-time ovulation synchronization program using GnRH and PGF2alpha improved pregnancy rates in peripuberal, lightweight replacement beef heifers.

Animals↗
PubMed2003

Effect of pretreatment with bovine somatotropin (bST) and/or gonadotropin-releasing hormone (GnRH) on conception rate of dairy cows with ovarian cysts subjected to synchronization of ovulation and timed insemination.

The objective of this study was to determine the effect of pretreatment with bovine somatotropin (bST) and/or gonadotropin-releasing hormone (GnRH) 7 days prior to initiation of a protocol for synchronization of ovulation and timed insemination (Ovsynch) on conception rate (CR) of cows with ovarian cysts. A total of 254 lactating dairy cows with ovarian cysts was divided into four groups (Day 0). On Day 0, cows in Group 1 (n = 61) were pretreated with 500 mg bST, s.q., and 100 microg GnRH, i.m.; cows in Group 2 (n = 73) were pretreated with 100 microg GnRH, i.m.; cows in Group 3 (n = 59) were pretreated with 500 mg bST, s.q.; and cows in Group 4 (n = 61) received no pretreatment. All cows were subjected to the Ovsynch protocol 7 days later. All cows previously received routine bST treatment every 14 days until milk production decreased to a minimum level established by the management of the herd. CR was assessed using logistic regression after adjusting for timing of concurrent bST treatment relative to Day 0, parity, season at time of insemination, and days in milk (DIM) on Day 0. CR for cows in Group 3 (12%) was significantly lower (P < 0.05) than that for cows in Group 4 (27%), and CR for cows in Group 1 (18%) and Group 2 (15%) tended to be lower (P < 0.10) than that for cows in Group 4 (27%). From the results of this study, it was concluded that bST pretreatment decreased CR, and pretreatment with GnRH, and GnRH with bST tended to decrease CR in lactating dairy cows with ovarian cysts concurrently treated with bST and subjected to the Ovsynch protocol.

Animals↗