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PubMed2000

Territoriality as a paternity guard in the European robin, Erithacus rubecula.

To investigate the relative importance of paternity defences in the European robin we used behavioural observations, simulated intrusions and temporary male removal experiments. Given that paired males did not increase their mate attendance, copulation rate or territory size during the female's fertile period, the most frequently quoted paternity assurance strategies in birds were absent. However, males with fertile females sang and patrolled their territories more regularly, suggesting that territorial motivation and vigilance were elevated when the risk of cuckoldry was greatest. In addition, there was a significant effect of breeding period on response to simulated intrusions: residents approached and attacked freeze-dried mounts more readily in the fertile period. During 90-min removals of the pair male in the fertile period, neighbours trespassed more frequently relative to prefertile and fertile period controls and appeared to seek copulations with unattended females. When replaced on their territories, males immediately increased both song rate and patrolling rate in comparison with controls. We propose that male robins sing to signal their presence, and increase their territorial vigilance and aggression in the fertile period to protect paternity. Copyright 2000 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMedDate not supplied

Selection responses for the number of fertile eggs of the Brown Tsaiya duck (Anas platyrhynchos) after a single artificial insemination with pooled Muscovy (Cairina moschata) semen.

A seven-generation selection experiment comprising a selected (S) and a control (C) line was conducted with the objective of increasing the number of fertile eggs (F) of the Brown Tsaiya duck after a single artificial insemination (AI) with pooled Muscovy semen. Both lines consisted of about 20 males and 60 females since parents in each generation and each female duck was tested 3 times, at 26, 29 and 32 weeks of age. The fertile eggs were measured by candling at day 7 of incubation. The selection criterion in the S line was the BLUP animal model value for F. On average, 24.7% of the females and 15% of the males were selected. The direct responses to the selection for F, and correlated responses for the number of eggs set (Ie), the number of total dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) were measured by studying the differences across the generations of selection between the phenotypic value averages in the S and C lines. The predicted genetic responses were calculated by studying the differences between the S and C lines in averaged values of five traits of the BLUP animal model. The selection responses and the predicted responses showed similar trends. There was no genetic change for Ie. After seven generations of selection, the average selection responses per generation were 0.40, 0.33, 0.42, 0.41 genetic standard deviation units for F, M, Dm, and H respectively. Embryo viability was not impaired by this selection. For days 2-8 after AI, the fertility rates (F/Ie) were 89.2% and 63.8%, the hatchability rates (H/F) were 72.5% and 70.6%, and (H/Ie) were 64.7% and 45.1% in the S and C lines respectively. It was concluded that upward selection on the number of fertile eggs after a single AI with pooled Muscovy semen may be effective in ducks to increase the duration of the fertile period and the fertility and hatchability rates with AI once a week instead of twice a week.

Animals↗
PubMedDate not supplied

[Female fertility in transition period].

In the last period, women fertility declined significantly. A series of factors were taken into account in a survey that included a number 440 women from Iaşi county. More than half of the women have one (27.14%) or two children (30%) and almost 55% of women are satisfied with the number of children they already have. The main factors that seems to influence the fertility are: women age, duration of marriage and women profession.

Adolescent↗
PubMed1983

Assessing cohort birth expectations data from the Current Population Survey, 1971-1981.

Data from the fertility supplements to the Current Population Survey from 1971 to 1981 indicate that in the aggregate, the lifetime birth expectations of married women 18 to 39 years old in 1971 will closely approximate their completed cohort fertility. During this period, the youngest group of women, 18 to 24 years old, delayed their childbearing; their short-term expectations (1971-76) were not realized, but they made up enough births in the latter half of the decade to enable them to attain their lifetime birth expectations. In retrospect, the "failure" of birth expectations data to predict the "period" fertility downswing in the 1970s resulted not from poor predictions of married women, but rather from unanticipated marital and subsequent childbearing patterns of women who were single at the beginning of the decade. The authors conclude that birth expectations are useful predictors of completed cohort fertility, if adjustments are made to incorporate changes in the proportions married within the birth cohort.

Adolescent↗
PubMed1984

Volumetric vaginal aspirator may aid in natural family planning.

All natural family planning (NFP) methods are based on the determitnation of a woman's fertile period so that a couple may abstain from sexual relations or use a mechanical means of birth control during that time. Researchers are seeking more accurate methods of predicting the onset of ovulation in order to increase the effectiveness of NFP. A new device developed by Dr. Gebhard F.B. Schumacher, a fertility specialist at the University of Chicago who serves on FHI's Technical Advisory Committee, and Dr. Stepen J. Usala, a former medical student at the University's Pritzker School of Medicine, holds the promise of providing a new, cheap, and relatively simple way of predicting ovulation. Called a volumetric vaginal aspirator, the instrument allows women to measure their own vaginal fluid on a daily basis. In early studies of 7 women carefully studied over 18 menstrual cycles, a striking 3 fold to 30-fold increase in the volume of vaginal fluid occurred a few days before ovulation. Results from 12 more women for a total of 26 cycles confirmed the earlier studies. Blood samples were taken in order to measure the levels of estrogen, known to increase prior to ovulation, and luteinizing hormone, which peaks sharply on the day of ovulation, in the women studied. These confirmed that ovulation typically had occurred after the fluid volume increase. In addition, participants recorded their basal body temperature (BBT) upon awakening. Although the BBT does not predict ovulation, it frequently increases by 1/2-1 degree Fahrenheit after ovulation thus serving as an indicator of the end of the fertile period. The prototype of the vaginal aspirator is a disposable plastic syring marked at .05 milliliter intervals so that fluid levels can be easily measured. After the manufacturing process for the aspirator is perfected so that the instrument can be mass produced, Dr. Schumacher hopes that largescale clinical trials will be initiated in the US and abroad. The larger studies and an endocrine study are needed in order for effective rules to be developed for applying the method in either birth control or fertility enhancement. The vaginal aspirator could be useful not only for preventing unplanned pregnancy but also for aiding couples experiencing infertility to pinpoint the time that conception is most likely to occur. As an aid in birth control, the aspirator should have a success rate similar to or better than that of a diaphragm, Dr. Schumacher believes. Although the women testing the vaginal aspirator were ablet to use it without assistance, Dr. Schumacer emphasizes that some patient education will be necessary if it becomes commercially available. Fertility awareness teachers could incorporate it into their courses. Research on the volumetric vaginal aspirator has been supported by FHI and by Mothers' Aid Research Fund of Chicago Lying-In Hospital.

Clinical Laboratory Techniques↗
PubMed1989

Tissue-type plasminogen activator in rat oocytes: expression during the periovulatory period, after fertilization, and during follicular atresia.

The regulation of tissue-type plasminogen activator (tPA) in rat oocytes during the periovulatory period, in early embryos, and in oocytes during induced follicular atresia was studied using a quantitative chromogenic substrate assay. Oocytes and early embryos were collected from three ovulation models: 1) intact immature female rats treated with PMSG, followed by hCG 48 h later; 2) hypophysectomized immature rats treated with PMSG, followed by a GnRH agonist (GnRHa) 56 h later; and 3) adult cyclic rats on the mornings of proestrus and estrus and up to 5 days after fertilization. In addition, follicular atresia was induced by either withdrawal of diethylstilbestrol (DES) for 2 days or injection of GnRHa for 2 days in hypophysectomized DES-implanted immature rats. Treatment with PMSG alone did not increase oocyte tPA content (5-20 microIU/oocyte) in either immature rat model, but treatment with either hCG or GnRHa induced meiotic maturation and ovulation and increased tPA activity to 80 and 140 microIU/oocyte 24 h after hCG and GnRHa treatment, respectively. Northern blot analysis of total RNA extracted from oocytes of PMSG-treated rats indicated the presence of a specific tPA message at 22S. tPA levels were low in preovulatory oocytes obtained on proestrus morning and increased in ovulated oocytes on estrus morning. After fertilization, tPA levels remained high in the embryos on days 1-4 of pregnancy, but dropped dramatically on day 5. Furthermore, oocytes from atretic follicles of hypophysectomized DES-implanted rats after either DES withdrawal or GnRHa treatment contained elevated levels of tPA, coincident with germinal vesicle breakdown (GVBD). Immunohistochemical staining revealed tPA antigen only in those oocytes that had undergone apparent meiotic maturation, as confirmed by GVBD. Thus, oocytes contain tPA mRNA and synthesize the active protease under a variety of stimuli which result in GVBD. The observed periovulatory increase in oocyte tPA activity, its maintenance until day 5 of pregnancy, and expression of tPA in nonovulatory oocytes of atretic follicles suggest diverse functions for the oocyte and embryo tPA.

Animals↗
PubMed1985

An estrogen test to determine the times of potential fertility in women.

Defined changes in the concentration of estrone glucuronide in daily samples of early morning urine have been used to locate the limits of the fertile period and the time of maximum conception probability during 118 cycles (106 menstrual, 12 conceptional) in 73 women. The peak day of urinary luteinizing hormone was used as an index of ovulation. Follicular growth was monitored daily by ultrasonography throughout 38 cycles, and the time of maximum follicular diameter was used as an alternative reference point to define the times of potential fertility according to the life spans of the gametes. With optimized algorithms and the best index of ovulation, the estrogen test delineated the limits of the fertile period in 89% of the tests (mean length, 10.8 days; range, 5 to 17 days) and the time of maximum conception probability in 82% of the cycles, with a mean time to the maximum follicular diameter of 0.42 days (range, -4 to +4 days).

Adult↗
PubMed1990

[The evaluation of fertility characteristics in hens using fluorescence microscopy].

A method for the assessment of fertility in domestic hens is described. Vitelline membranes of fertilized eggs were coloured with fluorochrome DAPI, following which the DNA of sperms on these membranes has been examined with the help of fluorescence microscopy. After insemination with frozen semen there exist significant correlations between the number of sperms on the vitelline membranes on the one hand and 1) fertilization rates; 2) the length of fertile periods. Furthermore, it was observed that with higher numbers of sperms on the membranes, the length of the fertile periods tends to be shorter than with smaller numbers of sperm.

Animals↗
PubMed1993

A new diagnostic aid for natural family planning.

INTRODUCTION: We have studied the use-effectiveness of salivary ferning as a diagnostic testing aid to natural family planning. We used PG/53, a pocket microscope. MATERIALS AND METHODS: Use of natural family planning methods was studied in 32 women who used the new technology PG/53 to detect the fertile period. By this means the women observed their menstrual cycles and other markers of fertility, such as basal body temperature and appearance of cervical mucus. RESULTS: Of the 32 women participating in this research, 28 women had a good salivary test with positive ferning by the microscope in the same period as other markers of fertility. In 4 cycles the ferning was uninterpretable as there was no correspondence with the cycle phase. Ferning began 1-2 days before cervical mucus appearance, and lasted a mean of 6.2 days. Ferning occurred, on average, 7.2 days before the first day of temperature shift. CONCLUSIONS: There is a direct correlation between salivary ferning and fertile period. Salivary ferning may be used as a new parameter to aid women to detect the fertile period in combination with other symptothermal methods of ovulation detection. We now need further research in order to improve the use-effectiveness of salivary ferning.

Body Temperature↗
PubMed1990

[Relationship between the intensity of gynecologic supervision during the postpartum period and fertility results in dairy cow herds].

The efficiency of regular post-partum gynaecological care in the dairy cow can only be correctly evaluated if cows with a normal post-partum period and those with problems during this time are distinguished. From 1,125 dairy cows being fed a high proportion of maize silage it was shown that gynaecological examinations on days 12, 28 and 40 post-partum had a positive effect on herd fertility. Regular checks resulted in significant reductions in the calving to conception interval, the insemination index and in the percentage culled due to fertility problems in comparison to the control animals (n = 451) where veterinary control took place only occasionally. In particular the early detection and treatment of endometritis and ovary function abnormalities contributed to a high conception rate with appropriate calving interval. The administration of GnRH (20 micrograms Buserelin) to cows with problems in the post-partum period and under continuous gynaecological supervision resulted in improvements in only some aspects (uterine involution, ovarian cyst incidence). The conception rates in the treated group and in the intensively controlled group were the same.

Animals↗
PubMed2006

Influence of macro and micro minerals in the peri-parturient period on fertility in dairy cattle.

Infertility in dairy cattle is a complex, multi-factorial problem that cannot be evaluated in isolation of other diseases and disorders. Clearly there is a role for the prevention of problems in the peri-parturient period, in particular hypocalcaemia, mastitis, lameness and retained placenta (RP), that all have a negative impact on the subsequent fertility of the cow. Minerals, trace elements and vitamins play a vital role in the prevention of these disorders at this time. Macro minerals are involved in the acid base status of the dairy cow and influence calcium metabolism. The use of anionic salts in combination with adequate calcium and magnesium supplementation may help to improve dry matter intakes and reduce negative energy balance in the post-calving period as well as prevent hypocalcaemia. Vitamin E and zinc are effective in prevention of mastitis that occurs predominantly in the first weeks of lactation, through enhanced antioxidant function and keratinisation of the teat canal. Lameness in dairy cattle also occurs mainly in lactation though most of the original insults to the hoof can occur prior to calving. Zinc and biotin are implicated in improving keratinisation of the hoof and prevention of this disease. Organic forms of zinc are retained better than inorganic sources and may provide greater benefit in disease prevention. Retained placenta can be reduced by prevention of hypocalcaemia and also adequate selenium status of the dairy cow. Selenium yeast is known to have higher retention in tissues and may play an important role in ensuring sufficient selenium is available to the cow for reduction of disease.

Animal Nutritional Physiological Phenomena↗
PubMed2001

Succession of microbial communities during a biostimulation process as evaluated by DGGE and clone library analyses.

AIMS: The objective of this study was to investigate the changes in the indigenous bacterial community structure for assessing the impact of biostimulation on spilled oil. METHODS AND RESULTS: Changes in the bacterial community structure were monitored by denaturing gradient gel electrophoresis (DGGE) and clone library methods based on 16S rRNA gene (rDNA) sequences. The results of DGGE, coupled with the use of the Shannon index and principal component analysis (PCA) and clone library analyses, were consistent. In the treated (fertilized) area, one operational taxonomic unit (OTU) became dominant during the fertilization period, and it was most closely related to Pseudomonas putida. CONCLUSIONS: The bacterial community structure in the treated area was markedly different from that in the control (non-fertilized) area during the fertilization period, but in the two areas it became similar at 14 weeks after the end of fertilization. SIGNIFICANCE AND IMPACT OF THE STUDY: The results suggest that the bacterial community structure was disrupted by the biostimulation treatment, but that it recovered immediately after the end of fertilization.

Bacteria↗
PubMedDate not supplied

Characteristics of natural conceptual cycles occurring in a prospective study of sex preselection: fertility awareness symptoms, hormone levels, sperm survival, and pregnancy outcome.

A prospective study of sex preselection provided the opportunity to characterize the fertile menstrual cycle. We describe from 91 natural conceptual cycles, or sub-groups thereof, cervical mucus symptoms, basal body temperature (BBT) changes, hormonal characteristics, and the outcome of pregnancy. The cervical mucus symptoms defined a potential fertile period of 10 days' average length, with the "peak" mucus symptom occurring at a mean of day 15.5 of the cycle. A fertile period of 9 to 10 days was also indicated by pregnancies resulting from single acts of intercourse between -6 and +3 days from ovulation. The BBT chart was biphasic in 73 of 76 cycles. The duration of the LH surge as observed in early morning urine samples averaged five days, with the peak occurring 1.4 days after the onset. Considerable inter-subject variability was seen in the LH excretion levels. Hormone measurements of peripheral plasma during the luteal phase showed the first detectable presence of hCG between day 7 and day 13 after conception. Progesterone concentrations in the midluteal phase exceeded 20 nmol/L and tended to be higher than in a comparison group of nonfertile cycles, whereas the estradiol concentrations were similar in fertile and nonfertile cycles. The birth sex ratio favored males when intercourse preceded ovulation/fertilization by two days or longer. While this association was statistically significant, the number of pregnancies involved is too small to conclude that the relationship is real.

Adult↗
PubMed1988

New insights on the mode of action of intrauterine contraceptive devices in women.

To gain a better understanding of the mechanism of action of intrauterine devices (IUDs), a search was made for ova in the genital tracts of 115 women using no contraception and of 56 women using IUDs, all of whom volunteered for study in conjunction with surgical sterilization. Ova were recovered from tubal flushings between 48 and 120 hours after the midcycle peak of luteinizing hormone in 39% of the IUD users compared with 56% of women in the control group (0.05 less than P less than 0.10). This suggests an action of the IUD before the ovum reaches the uterus. Eggs with a microscopic appearance consistent with fertilization were recovered from the fallopian tubes of half of the women using no contraception who had intercourse within the fertile period of the reproductive cycle and from whom ova were recovered. In contrast (P less than 0.01), no eggs with this appearance were recovered in IUD users who had intercourse within the fertile period. No ova were recovered from the body of the uterus of any of the IUD users. Fertilized ova are less likely to reach the uterine cavity containing an IUD. Thus, the principal mode of IUDs is by a method other than destruction of live embryos.

Fallopian Tubes↗
PubMed1996

The CUE Fertility Monitor compared to ultrasound and LH peak measurements for fertile time ovulation detection.

A prospective study of the reliability of the CUE Fertility Monitor to identify the fertile time of the menstrual cycle was conducted. The device provides a digital measurement of the electrical resistance of saliva (SER) and vaginal secretions (VL). The readings of the device were compared with the fertile time detected by ultrasonography of the growing follicle and estimation of the LH surge to detect ovulation. Thirteen women participated in the study. Sixteen cycles contained both signals (SER, VL) for the beginning and the end of the fertile period. In 2 cycles a CUE signal could not be found by the device. Using a computerized algorithm for evaluation of the CUE signals, the beginning of the fertile period was accurately detected in 14 cycles; in 2 cycles the signal was found less than five days prior to ovulation. The last day of fertility was identified correctly by the CUE Fertility Monitor in 10 cycles; in 6 it was incorrectly identified during the time when the woman was still fertile. This suggests that the CUE Fertility Monitor utilizing the algorithm on which it currently is based cannot be recommended for natural family planning. However, we think that the algorithm for evaluation should be improved as useful signals in the menstrual cycle are detected.

Adult↗
PubMed2000

Territorial intrusions and copulation patterns in red kites, Milvus milvus, in relation to breeding density.

Two main paternity assurance strategies are generally found in birds: mate guarding and frequent copulations. The latter is expected particularly in species such as raptors that cannot guard their mates efficiently because of ecological constraints, such as frequent courtship feeding. I investigated the prelaying behaviour of red kites, in which the males courtship feed. I compared pair behaviour in situations of varying breeding density and simulated male territorial intrusions by presenting decoys. Males' certainty of paternity was likely to decrease with increasing breeding density, because of the proximity of other males and more frequent male territorial intrusions during the presumed fertile period. The percentage of time spent by males within their breeding territory during the prelaying period was positively related to the number of close breeding neighbours, suggesting territory surveillance and mate guarding. The kites copulated frequently and over a long period. Copulation frequency prior to and during laying increased with breeding density, and in isolated pairs in response to simulated male territorial intrusions. The results support the idea of paternity assurance through frequent copulations during the presumed fertile period of the female, and suggest that early copulation activity is related to functions other than fertilization, such as pair bonding or mate assessment. Copyright 2000 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

Enhancement of bovine oocyte fertilization in vitro with a bovine oviductal specific glycoprotein.

The purpose of this study was to determine the effect of a partially purified bovine oviductal glycoprotein (bOGP) on fertilization rates of bovine oocytes. The effect of albumin (control protein) or bOGP at 100 micrograms ml-1 during the 16-18 h fertilization period was evaluated in a standard IVF system using a sperm concentration between 0.5 and 0.125 x 10(6) spermatozoa ml-1. bOGP maintained a higher (P < 0.05) fertilization rate (62.0% versus 31.2%) at 0.125 x 10(6) spermatozoa ml-1 compared with the albumin control. The enhancement of fertilization by bOGP was blocked by the inclusion of a specific antibody to bOGP, whereas the antibody with albumin had no effect. A 2 h gamete preincubation step was subsequently included in the IVF procedure (0.125 x 10(6) spermatozoa ml-1) to determine whether the effect of bOGP was mediated through an interaction with the oocyte, the spermatozoon or both. When oocytes were preincubated with bOGP the fertilization rates were higher (P < 0.05) than with the albumin control (oocytes and spermatozoa exposed to albumin), whereas preincubation of spermatozoa with bOGP did not affect fertilization rates. There was no synergistic effect of preincubating oocytes and spermatozoa with bOGP. The increase in fertilization rate achieved by preincubating oocytes with bOGP was blocked with a specific antibody to bOGP. These results suggest that the increase in fertilization rates observed when bOGP is included during the 16-18 h fertilization period are primarily mediated through the interaction of bOGP with the oocyte since the same facilitatory effect was observed with a 2 h preincubation of oocytes before IVF. The ability to block these effects with a polyclonal antibody specifically generated against bOGP shows that this biological activity is due to bOGP. In summary, bOGP enhances fertilization in bovine oocytes whether it is included during preincubation or insemination and this appears to be due to a direct effect on the oocyte.

Animals↗