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PubMed1995

Failed fertilization in vitro: second day micromanipulation of oocytes versus reinsemination.

OBJECTIVE: To compare routine reinsemination with 2nd day micromanipulation in patients with poor day 1 fertilization. DESIGN: A retrospective review of patient records. SETTING: The Mount Sinai Medical Center Assisted Reproductive Technologies Program. PARTICIPANTS: Patients undergoing IVF-ET who had poor fertilization (< 35%) with standard insemination and underwent second day reinsemination of oocytes (group I, n = 84) compared with patients who underwent 2nd day micromanipulation with subzonal insemination (group II, n = 12). MAIN OUTCOME MEASURES: Fertilization rate, cleavage rate, number of embryo transfers, and pregnancy rate. RESULTS: Fertilization rate and cleavage rate were significantly higher in group II patients. Pregnancies per transfer were similar between groups I (3/21, 14.3%) and II (0/9, 0%). Second day fertilization was possible in 9 of 12 group II patients, and fertilization rate was higher than day 1 in all nine, however, only 50% achieved cleavage, and none achieved pregnancy. CONCLUSIONS: Although micromanipulating oocytes that fail to fertilize may identify occult male factor infertility, may help the clinician plan future cycles, and may result in fertilization and even transfer of embryos in some cycles, there were no pregnancies in our series, and, for now, the clinical efficacy of this procedure remains in question.

Cleavage Stage, Ovum↗
PubMed1989

Hemizona assay: assessment of sperm dysfunction and prediction of in vitro fertilization outcome.

The hemizona assay (HZA) was used in a prospective, blinded study to assess the relationship between tight sperm binding in the HZA and sperm fertilizing ability in in vitro fertilization (IVF). In each controlled assay, the authors compared sperm binding of proven fertile men with that of patients undergoing IVF. Human oocytes stored in a salt solution were used in the study, and binding results were correlated with the fertilization rate of preovulatory oocytes during IVF. Patients with poor fertilization rates in IVF had significantly lower binding than those cases with successful fertilization (7.3 +/- 1.4 versus 62.1 +/- 10.9, respectively; mean +/- standard error, P less than 0.02). Based on current standards, the HZA was able to predict fertilization accurately in 26 of 28 cases (sensitivity of 83%, specificity of 95%, positive predictive value of 83%). The authors conclude that the HZA is a valuable tool for evaluating dysfunctional sperm-zona pellucida binding, with good predictive value for fertilization in vitro.

Adult↗
PubMed1998

Mannose ligand receptor assay as a test to predict fertilization in vitro: a prospective study.

OBJECTIVE: To assess whether mannose receptor assays can predict fertilization outcome in vitro. DESIGN: A prospective, double-blind study of the mannose receptor properties of spermatozoa. SETTING: Assisted human reproduction program at a university hospital. PATIENT(S): Partners of 140 consecutive women undergoing their first in vitro fertilization cycle. INTERVENTION(S): Motile sperm populations were tested for surface receptors for mannose by measuring their ability to bind fluorescein-labeled mannosylated albumin and to undergo a free mannose-induced acrosome reaction as judged by Pisum, sativum agglutinin binding. MAIN OUTCOME MEASURE(S): Mannose receptor assay results were correlated with fertilization outcomes using several statistical tests, including the chi2 test, chi2 for proportions, t-tests, analysis of variance with Student-Newman-Keuls tests and correlational and receiver operating characteristic (ROC) curve analysis. RESULT(S): The fractional increment increase on incubation in the percent of sperm binding mannose ligand over an intact acrosome correlated with fertilization rates in vitro. Threshold values of mannose ligand binding and of mannose-induced acrosome reactions predictive of fertilization rates were identified by ROC curve analysis. Men were thus classified into one of four groups with differing fertilization rates in vitro. CONCLUSION(S): The increment increase in sperm surface mannose ligand binding by acrosome-intact sperm correctly predicts high and low fertilization rates in vitro and identifies cases where conventional insemination can result in failed fertilization.

Adult↗
PubMed2003

Content and distribution of forms of organic N in soil and particle size fractions after long-term fertilization.

Most of the N in surface soils occurs in organic forms, and when mineralized it plays a key role in soil fertility and plant nutrition. Our objective was to study the effect of long-term applications of organic manure on the content and distribution of forms of organic N in bulk soil and soil particle size fractions to characterize the inherent soil nitrogen fertility. Five treatments were as follows: (1) CK (no fertilizer and no manure added), (2) mineral fertilizer only, (3) straw + NPK, (4) green manure + NPK and (5) pig manure + NPK. Soil particle size fractions (0-2, 2-10, 10-50 and 50-100 microm) were isolated without chemical pretreatment by ultrasonic dispersion in water followed by sedimentation. The content of total N and forms of organic N in the bulk soil increased after long-term fertilization, and the effect varied with fertilizer type. The plot treated with only mineral fertilizer gave the highest NH3-N and the lowest amino sugar-N content in all treatments. The highest content of amino sugar-N and amino acid-N was found in the treatment of pig manure + NPK. The content (g kg(-1) fraction) of hydrolysable N within size fractions was in the order 0-2 > 2-10 > 50-100 > 10-50 microm, but the contribution of different size fraction to hydrolysable N decreased in the sequence 10-50 > 0-2 > 2-10 > 50-100 microm. Most of the applied mineral fertilizer N that remained in soils was distributed in the particle size fraction < 2 microm while most of the remaining N from manure applied with NPK was transferred into amino sugar-N in each size fraction, and amino acid-N in the size fractions > 2 microm during the process of humification.

Fertilizers↗
PubMed2002

Effect of cumulus cell removal of in vitro matured bovine oocytes prior to in vitro fertilization on subsequent cleavage rate.

The aim of this study is to identify the effect of cumulus cells removal prior to the in vitro fertilization of matured bovine oocytes on cleavage rate. Denuded, matured oocytes were fertilized in presence or absence of loose cumulus cells, cumulus cell conditioned IVF medium (CCCM), charcoal-treated CCCM and charcoal-treated CCCM supplemented with progesterone at a final concentration of 150 ng/ml. After 18 h of incubation with sperm, the presumptive embryos were cultured on a BRL monolayer and the percentage of cleaved embryos was evaluated on Day 4. Removal of cumulus cells prior to IVF significantly reduced the cleavage rate (25% for denuded oocytes versus 56% for cumulus-oocyte complexes (COCs)). The addition of loose cumulus cells partially restored the effect of denudation (cleavage rate: 37% for denuded oocytes supplemented with loose cumulus cells versus 27% for denuded oocytes and 58% for COCs). CCCM also had a positive effect on the cleavage rate of oocytes denuded prior to IVF (36% for denuded oocytes fertilized in CCCM versus 14% for denuded oocytes). Treating the CCCM with charcoal resulted in complete loss of its effect on cleavage rate (18% for denuded oocytes fertilized in charcoal-treated CCCM versus 34% for denuded oocytes fertilized in CCCM). The addition of progesterone to charcoal-treated CCCM partially restored the reduction of the cleavage rate caused by charcoal treatment (27% for denuded oocytes fertilized in charcoal-treated CCCM supplemented with progesterone versus 14% for denuded oocytes fertilized in charcoal-treated CCCM and 36% for denuded oocytes fertilized in CCCM). In conclusion, removal of cumulus cells prior to IVF adversely affects the cleavage rate through loss of a factor secreted by these cells. This factor probably is progesterone.

Animals↗
PubMed2003

Effects of media, fertilization technique, extender, straw volume, and sperm to egg ratio on hatchability of cyprinid embryos, using cryopreserved semen.

To enable cryopreservation of fish semen to become an efficient, routine technique, much more detailed information is required. Therefore, the present study was conducted to investigate various fertilization techniques and media, straw volumes as well as optimal semen volume for cryopreservation. The bleak (Chalcalburnus chalcalburnus) was used as the main model for investigation. Using frozen-thawed semen the fertilization rate was similar up to the morula stage, independent of the fertilization technique. Thereafter, in egg batches fertilized using the wet technique most embryo development stopped. In egg batches fertilized using the dry technique, embryonic development proceeded normally. For cryopreserved semen full activation of sperm motility was obtained at ratios of fertilization media (hatchery water and all tested types of saline solutions) to semen of 10:1. Sperm motility rate was much higher in the saline solutions than in water. In contrast hatching rates were higher when water was used as fertilization medium. Therefore, the requirements necessary for optimal sperm motility and optimal sperm-egg contact were different and so for these parameters optimal levels could not be achieved. When adjusting the freezing and thawing conditions 0.5ml straws as well as larger straws (1.2ml) proved suitable for cryopreservation of cyprinid semen. The highest fertilization rates were obtained with sperm to egg ratios of (1.3-2.5) x 10(6):1 and were 77-92% of fresh semen control. This was also similar for Ch. nasus, R. meidingerii, B. barbatus and C. carpio and suggests that the cryopreservation requirements of spermatozoa are not species specific.

Animals↗
PubMed1998

Effects of follicular fluid on fertilization and embryonic development of bovine oocytes in vitro.

This study was conducted to evaluate the effect of bovine follicular fluid (BFF) on fertilizability and developmental capacity of bovine oocytes matured in vitro. Oocytes were collected from slaughterhouse ovaries, and matured in TCM199 supplemented with 5% superovulated cow serum (SCS), 2 mM pyruvate and 1 IU/mL PMSG. BFF was aspirated from small follicles (1 to 5 mm in diameter). In Experiment 1, BFF was added to the Brackett and Oliphant (BO) fertilization medium at concentrations of 0, 1, 5, 10 and 20%. After insemination with frozen-thawed and heparin-treated (10 micrograms/mL, 15 min) bull spermatozoa for 18 h, some of the oocytes were fixed and stained to evaluate the fertilization rate. The rest of the oocytes were co-cultured in serum-free embryo culture medium (ECM; TCM199 supplemented with 5% SCS, 2 mM pyruvate and 5 micrograms/mL insulin) with bovine oviductal epithelial cells (BOEC) at 38.5 degrees C under 5% CO2 in air, and the developmental capacity of embryos was examined at 2, 7 and 9 d. In Experiment 2, BFF was added to the serum-free ECM with BOEC at 0, 5, 10 and 20% concentrations, and embryos were cultured for 9 d. Fertilization rates and blastocyst rates in low (1 and 5%) BFF in fertilization medium were not significantly different from the control (without BFF). However, high concentrations of BFF (10 and 20%) in the fertilization medium suppressed both fertilization rates and development. Large vesicles with fast monolayer formation were observed at all concentrations of BFF added to ECM with BOEC. There were no significant differences in cleavage or development to blastocyst in different concentrations of BFF added to ECM. However, the rate of development to hatched blastocysts in 20% BFF was significantly lower than that of the control (P < 0.05). The results of the present study indicate that BFF addition to fertilization medium and ECM with BOEC does not improve fertilizability or developmental capacity and that high concentrations of BFF reduce the rate of both fertilization and development.

Animals↗
PubMed1994

Sperm function and its manipulation for microassisted fertilization.

Comprehension of the intricate complexities of sperm function is clearly crucial to the success of attempts to manipulate it for the purposes of assisted conception. This is particularly important when considering various procedures for microassisted fertilization since these bypass critical physiological events that are mandatory for normal fertilization, to varying degrees. Methylxanthine derivatives such as pentoxifylline are useful agents for the management of oligoasthenozoospermic patients. This is particularly so for procedures such as SUZI where adequate motility of spermatozoa injected into the perivitelline space is crucial for fusion with the vitelline membrane to achieve fertilization. The generation of minute concentrations of reactive oxygen species in vitro may prove to be a valuable technique in this respect, in the light of recent evidence for their involvement in capacitation and hyperactivation. Induction of the acrosome reaction by non-invasive, non-toxic agents should markedly improve success rates for microassisted fertilization. Acrosin appears to play a central role in this and, therefore, it would seem prudent to monitor levels of acrosin activity in samples of spermatozoa used in assisted conception procedures. With respect to microassisted fertilization, the potential to select recently acrosome-reacted spermatozoa coated by activated acrosin promises to be a major improvement. Current methods employed for determination of the fertilization potential of spermatozoa are clearly inadequate (Polansky and Lamb, 1988; Aitken, 1990). In fact, the prevailing evidence suggests that no single parameter of sperm function reflects this potential (Zaneveld and Jeyendran, 1988). Therefore, we have both a scientific and a moral responsibility to investigate these processes further. Subsequently, we should be in a position to identify individual gametes with the potential for fertilization and so utilize procedures that result in maximal fertilization rates with minimal risk of polyploidy or abnormality.

Autoantibodies↗
PubMed2003

Influence of nitrogen fertilizers on the yield and composition of thyme (Thymus vulgaris).

The influence of nitrogen fertilizers on the yield of crop, as well as on the production and composition of the essential oil and some other chemical characteristics of thyme, was investigated. Different levels of fertilizers (N = 0, 45, 90, and 135 kg x ha(-)(1)) were applied. It was found that fertilizers increase thyme crop, but differences in the yield of essential oil were not remarkable. However, the use of certain amounts of nitrogen fertilizers resulted in higher yields of essential oil obtainable from the cultivation area unit (dm(3) ha(-)(1)). Totally, 61 constituents were identified in thyme essential oil by capillary GC and GC-MS. Thymol was the dominating compound in the all analyzed oils (44.4-58.1%), followed by p-cymene (9.1-18.5%), gamma-terpinene (6.9-18.9%), and carvacrol (2.4-4.2%). Differences in the percentage of these and other compounds in thyme herb cultivated under different fertilization doses were not significant; very slight changes in the percentage composition were detected after drying. Some variations in the amount of individual constituents expressed in arbitrary units per kilogram of herb (which is almost equivalent to mg x kg(-)(1)) were observed. The highest amounts of sugars and sucrose, in particular, were determined in the second year of thyme cultivation. Differences in the content of dry soluble substances were not meaningful, and there was no effect of nitrogen fertilizers on this chemical characteristic. Some effect of fertilization on the content of vitamin C and carotenes was observed in the first year of thyme cultivation. It was determined that nitrogen fertilizers influence the amount of nitrates, which was highest in the second-year-first-harvest.

Ascorbic Acid↗
PubMed2002

Sperm immobilizing antibodies in the sera of infertile women cause low fertilization rates and poor embryo quality in vitro.

PROBLEM: The effects of sperm immobilizing antibodies in the sera of infertile women on fertilization and embryo quality in vitro were investigated. METHOD OF STUDY: Before the introduction of sperm immobilization test (SIT) as a routine test for female infertility, 85 oocytes were collected in nine in vitro fertilization (IVF) cycles from four infertile women who were afterward found having had sperm immobilizing antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium containing the patient's serum. Fifty oocytes were collected in five IVF cycles from five infertile women possessing the antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium supplemented with human serum albumin (HSA). RESULTS: In the former group, 41 of 85 oocytes were fertilized, giving a fertilization rate of 48.2%. In the latter group, 43 of 50 oocytes were fertilized, giving a fertilization rate of 86.0%. There was a significant difference of the fertilization rate between the groups (P < 0.0001). Embryo quality was assessed by the Veeck's classification. The grade 1 and grade 2 embryos were considered good quality. Using this classification, 16 (39.0%) of 41 embryos incubated in the medium containing the patient's serum were good quality, while 34 (79.1%) of 43 embryos incubated in the medium supplemented with HSA were good quality. There was also a significant difference between the groups (P = 0.0003). CONCLUSIONS: These findings might indicate that sperm immobilizing antibodies in the sera of infertile women cause low fertilization rates and poor embryo quality in vitro. It is suggested that SIT in the sera of infertile women should be performed at least before proceeding IVF. The manipulation of gametes and embryos from patients having sperm immobilizing antibodies should be carefully carried out especially to avoid contaminating patient's serum and follicular fluid in the culture medium in order to have a better IVF result.

Culture Media↗
PubMed1991

Genetic specification of life span and self-fertility in recombinant-inbred strains of Caenorhabditis elegans.

The genetic basis of life-span and age-specific fertility has been analysed using recombinant-inbred strains of the nematode Caenorhabditis elegans. Estimates of narrow-sense heritability range from 0.05 to 0.36 for life span and from 0.36 to 0.49 for total self-fertility. Positive phenotypic and genetic correlations for life span and total fertility were also observed, although in most cases the correlations were not significant. In general, age-specific hermaphrodite fertility was positively correlated with fertility on contiguous days but was negatively correlated with fertility on more distant days. We estimate that a minimum of two to three genes specify each of these traits in this genetic background. Three single-gene markers were used to generate strain distribution patterns, and two of these were found to be linked with loci that specify life span and/or fertility. We also saw evidence for a significant environmental component affecting self-fertility.

Animals↗
PubMed2005

Fertility following spinal cord injury: a systematic review.

STUDY DESIGN: Systematic review. OBJECTIVES: To review systematically fertility of persons with spinal cord injuries (SCI) and their partners. METHODS: Reports from six databases (1966-2003), selected annual proceedings (1997-2002) and manufacturer's information were screened against eligibility criteria. Searches covered female obstetrical issues, and the efficacy of vibration and electroejaculation for males, as well as advanced fertility (AF) treatments for partners of SCI males. Data were pooled from case-series reports on SCI males' ejaculation, and pregnancies and live births for partners of SCI males. RESULTS: In all, 2,127 unique reports were evaluated, of which 66 reports were included. No studies investigated fertility in SCI females. Ejaculation interventions in the last decade resulted in response rates of 95% (95% confidence intervals (CI) 91%, 99%), with 100% response rate reported in several recent publications. A total of 13 studies (1993-2001) yielded pregnancy rates of 51% (95% CI 42%, 60%) in partners of SCI males. Of these, 11 studies (1993-2003) yielded live birth rates of 41% (95% CI 33%, 49%). CONCLUSIONS: Fertility of SCI males is extensively studied. Semen for fertility purposes can generally be obtained using vibration and electroejaculation. AF techniques are increasing pregnancy rates. Research is needed to improve sperm quality. Freezing of sperm is unlikely to significantly improve fertility rates. Fertility of SCI females is addressed only in case reports and opinion articles. The opinion that female fertility is unaffected by SCI should be further investigated using appropriate research methodology.

Birth Rate↗
PubMed2003

Impact of low birthweight on subsequent fertility: population-based register study.

Adverse birth outcomes may influence a family's wish for additional children. We investigated the influence of low birthweight in live births on subsequent fertility, and estimated secular trends of such an effect in a population-based cohort study of births arranged in consecutive sibship records in the Medical Birth Registry of Norway. We included births of order one to seven to all 587 785 mothers in Norway who had a first singleton birth in 1967-91. Associations between birthweight in 1 158 072 surviving index births of order one to six, 1967-91, and subsequent fertility (probability of another birth), 1967-97, were estimated as fertility ratios in Cox regression analysis. Giving birth to a live infant weighing < 3000 g had a negative effect on subsequent fertility, increasingly strong for decreasing birthweight. Low birthweight (<2500 g) was associated with a fertility ratio of 0.88 [95% confidence interval 0.87, 0.89]. This negative impact was stronger if the mother had also given birth to surviving children of low birthweight previously, particularly if combined with caesarean section in the most recent birth. The negative fertility effect of low birthweight grew slightly stronger between 1967 and approximately 1980, according to year of first birth. This trend paralleled reduced population fertility in the same period. The moderate negative impact of giving birth to a live infant of low birthweight on subsequent fertility could result from the combination of reduced wish for additional children and biological subfertility.

Female↗
PubMed1999

Sperm penetration through the human zona pellucida as a predictor of in vitro fertilization.

The aim of this study was to determine the predictive value of sperm penetration into the perivitelline space of human cadaveric oocytes on in vitro fertilization outcome. Forty-two patients with tubal infertility undergoing ovarian stimulation with gonadotropin for in vitro fertilization and embryo transfer participated in the study. The number of spermatozoa bound to the human zona pellucida, the percentage of cadaveric oocytes with one or more spermatozoa in the perivitelline space, and the in vitro fertilization outcome were evaluated. Spermatozoa from 37 of 42 patients were able to penetrate the perivitelline space of cadaveric oocytes as well as to fertilize human oocytes in vitro. In three individuals, no penetration of the perivitelline space of cadaveric oocytes was observed and no in vitro fertilization was detected. Only two patients were able to fertilize the couple's oocytes without penetration of the cadaveric oocytes. Based on these results the specificity and the sensitivity of the assay to predict in vitro fertilization was 100% and 94.1%, respectively. Accordingly, these results suggest that sperm-zona penetration is a useful bioassay to predict male fertility potential in IVF outcome.

Female↗
PubMed2003

Assessing in vivo fertilizing capacity of liquid-preserved boar semen according to the 'Hanover gilt model'.

The goal of this study was to determine the ability of the Hanover gilt model to assess in vivo fertilizing capacity of preserved sperm and to consider whether any modifications to this model were needed. This model evaluates the fertilizing capacity of semen based on the fertilization rate, the rate of normal embryos and the accessory sperm count of 3-5-day embryos. Its distinguishing characteristics are the use of one-time insemination of sperm in reduced numbers, of spontaneously ovulating gilts and of ovulation detection through ultrasound examination of ovaries. Reduced sperm numbers allow for an accurate evaluation of the fertilizing potential of different semen treatments, thereby avoiding the compensatory effect of doses calibrated to maximize fertility. The model's usefulness was assessed in a trial run designed to compare the fertilizing capacity of liquid boar semen diluted into two different extenders. The diluent, the boar and the backflow, had no significant effect on any of the parameters studied. Gilts inseminated less than 24 h before ovulation had a significantly higher (p < 0.01) fertilization rate and accessory sperm cell count (p < 0.05) than those inseminated more than 24 h before ovulation. Very good/good embryos from homogeneous litters (only very good/good embryos were present) had a significantly higher (p < 0.01) accessory sperm count than those from heterogeneous litters (at least one embryo was of a different quality and/or oocytes were present). Both very good/good and degenerated/retarded embryos from heterogeneous litters had low accessory sperm numbers. This suggests that accessory sperm count is significantly related to the quality of the litter, but not to the quality of the embryo within gilts. It can be concluded that the Hanover gilt model is sensitive enough to show fertility differences (in this study, those associated with in vivo ageing of semen), while using relatively few gilts and little time.

Animals↗
PubMed2002

Fertility of male and female emus (Dromaius novaehollandiae) as determined by spermatozoa trapped in eggs.

Changes in the fertility status of 10 pairs of emus were investigated using egg break-out and numbers of sperm in the perivitelline membrane of the germinal disc (GD) region. After the sexes were separated, sperm in consecutive eggs declined approximately logarithmically at a mean (+/-SEM, n = 10 females) rate of -0.148 +/- 0.021 per log day. Sperm continued to be detected in eggs for 16.5 +/- 1.7 days during which 5.6 +/- 0.6 fertilized eggs were laid. Fertilized eggs that did not contain detectable sperm were laid by five females for a further 2.2 +/- 0.9 days. Based on break-out fertility, the fertile period continued for up to 18.7 +/- 2.1 days, for which the mean number of laid eggs was 6.3 +/- 0.8. An egg with a 50:50 chance of being fertilized would contain 3.5 sperm mm(-2) of GD. Based on the sperm decline model, an egg containing that many sperm would be laid 21 days after the last copulation. In emus that were not separated and allowed to incubate their eggs (n = 3 pairs), the number of sperm in eggs laid before and during incubation declined in a manner similar to that after the last copulation and egg-laying stopped after the females had laid 3.3 +/- 0.3 eggs. After incubation was terminated, females resumed laying within 8.3 +/- 1.2 days and the number of sperm in eggs gradually increased but it did not return to pre-incubation levels. In non-incubating emus (three pairs), the number of sperm in eggs declined as laying progressed, although lit was higher during the period when the first seven eggs were laid than during the period when the rest of eggs were laid (214 +/- 39 v.100 +/- 16 sperm mm(-2) of GD). Sperm numbers varied between successive eggs but a sharp increase followed by a decrease acted as an indicator of recent copulation. There were 8.7 +/- 0.3 such increases per laying period (one per 2.8 +/- 0.2 eggs), a frequency that suggests that emus copulate once weekly. In conclusion, as long as a female emu is supplied with sperm on a weekly basis, she will be fertile but, when copulations stop, she will stop laying soon after. Male fertility appears to fall towards the end of the laying season and it can be affected by egg incubation at any time of the season.

Animals↗
PubMed1993

Fertility of superovulated ewes after intrauterine or oviducal insemination with low numbers of fresh or frozen-thawed spermatozoa.

Two experiments investigated the effects of number of spermatozoa inseminated and time and site of insemination of fresh and frozen-thawed semen on fertility in Merino ewes treated with intravaginal progestagen pessaries and a combination of pregnant mare serum gonadotrophin and follicle stimulating hormone. In Experiment 1, ewes were inseminated in the uterus or oviducts with totals of 10(4), 10(5), 10(6) or 10(7) fresh spermatozoa 44 or 68 h after pessary removal. Ova recovered 48 h later were classified as fertilized if they had cleaved. Proportion of fertile ewes (ewes with fertilized ova per ewes inseminated) and fertilization rate of ova (ova fertilized per ova recovered) were higher for inseminations 44 h (63% and 45%) than 68 h (38% and 19%) after pessary removal (P < 0.001). More ewes were fertile after oviducal (61%) than after intrauterine insemination (39%; P < 0.05), and with high (10(6) and 10(7)) than with low (10(4) and 10(5)) doses of spermatozoa for intrauterine (54% v. 24%; P < 0.05) but not for oviducal inseminations (63% v. 59%). Fertilization of ova was better after oviducal than after intrauterine inseminations (44% v. 22%; P < 0.001), and with high than with low doses of spermatozoa (45% v. 21%; P < 0.001). In Experiment 2, ewes were inseminated with 10(5), 5 x 10(5) or 10(6) total fresh or frozen-thawed spermatozoa in the uterus or oviducts, 44 h after pessary removal.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Selection responses in duration of fertility and its consequences on hatchability in the intergeneric crossbreeding of ducks.

1. From 1992 to 2003, selected (S) and control lines (C) of the laying Brown Tsaiya duck (Anas platyrhynchos) were simultaneously maintained under the same standardised conditions of feeding and management. 2. The selection objective was to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. From generations G1 to G11, 2452 and 2022 female ducks, in S and C lines, respectively, were measured and recorded. In the S line, the percentage selected varied between 20.2 and 34.3% in females and between 7.2 and 20.8% in males. 3. Selection for number of fertile eggs had a correlated effect of increasing the parameter tau of the logistic curves which fitted the daily variations (d 2 to 15) in fertility or hatchability on the basis of eggs set. The differences S-C for the estimates of the times of half maximal fertility and hatchability increased by 0.41 and 0.37 d per generation between G1 and G11, respectively. 4. The highest increases of fertility per day rates after a single AI were observed between d 5 and 11. Moreover, in the selected line, fertility rate was higher than, or equal to, 90% in d 2 from G8. The same tendencies were observed for the changes in the evolution of hatchability on the basis of eggs set. 5. Selection increased fertility and hatchability according to the egg set rates, especially for d 2 to 8 after AI. Hatchability of fertile eggs was not impaired, confirming that selection for one AI per week was possible in this strain of laying ducks.

Animal Husbandry↗