Animal reproduction science.
Publisher:
Elsevier Scientific Pub. Co.
Frequency: Twenty eight no. a year, 2008-
Country: Netherlands
Language: English
Start Year:1978 -
ISSN:
0378-4320 (Print)
1873-2232 (Electronic)
0378-4320 (Linking)
1873-2232 (Electronic)
0378-4320 (Linking)
Impact Factor
2.2
2022
| NLM ID: | 7807205 |
| (DNLM): | A31035000(s) |
| (OCoLC): | 04122595 |
| Coden: | ANRSDV |
| LCCN: | sc 80000012 |
| Classification: | W1 AN228V |
Levels of selected T lymphocyte subpopulations in peripheral blood of mares which experienced early embryonic death. The objective of the present study was to analyse the immune status of mares in the early stages of pregnancy and mares which experienced early embryonic death (EED). Forty-eight fertile purebred Arabian mares were used for the study. The mares were divided into two groups. Group I was the control group composed of 32 mares in the early stages of a normal pregnancy. Group II was composed of 12 mares which had experienced EED. In both groups, subpopulations of T lymphocytes containing CD2(+), CD4(+) and CD8(+) were characterized using flow cytometry. The percentages of CD3(+) lymphocytes (addin...
Effect of season on fresh and cryopreserved stallion semen. The objective of this study was to determine the effect of season on sperm quality variables, expression of the fertility-related protein SP22 and selected mRNA transcripts in fresh and cryopreserved stallion sperm. Four stallions were collected in each of the four seasons: summer, fall, winter and spring. Ejaculates were divided and then evaluated for motility, morphology, SP22 staining and expression of selected mRNAs as either fresh semen samples or cryopreserved samples. A significant interaction between season and cryopreservation status was found for total and progressive sperm motility....
Changes in the expression of the miu-opioid receptor in the mare oviduct during oestrus and anoestrus. The presence of the mu-opioid receptor (MOR) was investigated in the mare oviduct during oestrus and anoestrus, by means of immunoblotting and immunohistochemistry. Immunoblotting analysis showed that the MOR protein is expressed as 65, 50 and 30 kDa forms in the infundibulum and ampulla both in oestrus and anoestrus, while the 30 kDa form is absent in the isthmus. Moreover, different levels of expression were observed along the ampulla in the two periods examined. Immunohistochemistry revealed MOR in the mucosal epithelium, stromal cells, myocytes and blood vessels. Ciliated cells expressed M...
Luteal function induced by transvaginal ultrasonic-guided follicular aspiration in mares. Ultrasonic-guided transvaginal follicle aspiration was performed in 58 crossbreed mares in order to determine whether aspiration of various dominant follicle diameters resulted in luteal tissue capable of producing progesterone (P(4)). The mares were randomly assigned to three groups according to follicular diameter (25-29 mm; 30-35 mm and >35 mm). Mares that had ovulations naturally served as controls. The serum progesterone (P(4)) concentrations in the aspirated mares were greater (P < 0.0001; r(2) = 0.6687; CV = 21.52) in mares with natural ovulation compared to mares with aspirated follicl...
Evaluation of shape variability of stallion sperm heads by means of image analysis and Fourier descriptors. This study quantified and evaluated the variability of sperm head shape for 10 different stallions. Sperm head shape characteristics including sperm head length to width ratio, position of the center of gravity, curvature, and degree of roundness were assessed and analysed from images using elliptic Fourier descriptors and inverse Fourier transformation. The first four principal components accounted for 88.46-92.33% of the total variance and provided a good summary of the overall data. In the case of the ejaculate with defective sperm heads the components accounted for 97.35-98.21% of variatio...
Markers of the uterine innate immune response of the mare. Reproductive efficiency in mares is low and persistent mating-induced endometritis (PMIE) is an important cause of subfertility. Mating-induced endometritis (MIE) an obligate precursor to PMIE, is a ubiquitous, transient inflammatory response to the presence of sperm, seminal components and pathogens. However, the specific inflammatory pathways that derive from MIE and that may also be precursors to PMIE are not clear. The ability to identify and measure robust, repeatable markers of inflammation integral to MIE may be key to understanding the progression to PMIE. The aim of the study was to (...
Functional relationships among intrafollicular insulin-like growth factor 1, circulatory gonadotropins, and development of the dominant follicle in mares. The functional relationships among intrafollicular free insulin-like growth factor 1 (IGF1), circulatory gonadotropins, and development of the dominant follicle were studied in 40 mares in two experiments. A GnRH antagonist (Acyline) was given i.m. at the expected beginning of follicular deviation (largest follicle or F1> or =20mm; Day 0) alone (Acyline group) or in combination with intrafollicular treatment of F1 with rhIGF1 (Acyline/IGF1 group). In Experiment 1, blood samples, follicular-fluid samples, and diameter of F1 were taken on Days 1 and 2. In Experiment 2, daily follicular diamet...
Cholesterol addition protects membrane intactness during cryopreservation of stallion sperm. Addition of cholesterol to sperm membranes improved equine sperm stability during semen cryopreservation; however, it also reduced in vivo fertility. The objective of the present study was to determine the effects of adding cholesterol to stallion sperm prior to freezing, and subsequently removing it from frozen-thawed sperm. Semen from 12 stallions was subjected to four treatments: (T1) control, semen was diluted with Kenney extender, centrifuged, and resuspended to 100 x 10(6)spermatozoa/mL in INRA 82 freezing extender, packaged into 0.5-mL straws, cooled to 5 degrees C, and cryopreserved in...
The first ovulation of the breeding season in the mare: the effect of progesterone priming on pregnancy rate and breeding management (hCG response rate and number of services per cycle and mare). The mare is a seasonally polyestrus breeder. In early spring, the mare enters a "transition period" between the anovulatory season and the first ovulation of the year. This period is characterized by irregular estrus cycles and high incidence of regressing dominant follicles. There is a belief that pregnancy rates resulting from the first ovulation of the season is lower than in subsequent ovulations, however this has never been studied critically. Progestagens are often used as an aid to manage the transition period. The objective of this study was to compare pregnancy rates of mares from the...
Cholesterol-loaded-cyclodextrins and fertility potential of stallions spermatozoa. Irreversible damage occurs to spermatozoal membranes, during the phase transition, when spermatozoa are cooled from room temperature to 5 degrees C. Some of this damage can be ameliorated by adding cholesterol to the membrane, thereby altering membrane lipid composition. Adding cholesterol-loaded cyclodextrins (CLCs) to stallion spermatozoa prior to freezing, increases cell cryosurvival. However, the fertilizing potential of CLC-treated stallion spermatozoa is unknown. To address this, experiments were conducted which evaluated the ability of CLC-treated stallion spermatozoa to capacitate, acr...
Influence of seminal plasma on fertility of fresh and frozen-thawed stallion epididymal spermatozoa. The use of epididymal stallion spermatozoa for routine artificial insemination can secure easy future use of valuable genetics after unforeseen death or injury of a valuable stallion. The aims of this study were to (1) directly compare pregnancy rates for fresh and frozen-thawed stallion epididymal and ejaculated spermatozoa after conventional artificial insemination and (2) to investigate the effect of seminal plasma on the fertility of epididymal spermatozoa after insemination. Twenty-one mares were randomly assigned to three stallions. Mares were inseminated at five consecutive oestrous per...
Osmotic stress stimulates generation of superoxide anion by spermatozoa in horses. The objective of this study was to examine the interplay between osmotic and oxidative stress as well as to determine mechanisms by which osmotic stress increases superoxide generation in spermatozoa of horses. Superoxide production, as measured by dihydroethidium (DHE), increased when spermatozoa of horses were incubated under either hyperosmotic or hyposmotic conditions. This increase in superoxide production was inhibited by the MAP kinase p38 inhibitor, SB203580, and by the superoxide scavenger, tiron. Incubation of spermatozoa under hyperosmotic conditions increased overall protein tyrosi...
Reproductive efficiency of Thoroughbred mares under Indian subtropical conditions: A retrospective survey over 7 years. Service records of 253 mares (1181 mare-years) spanning over 7 consecutive years, from nine organized Thoroughbred stud farms, situated in the subtropical northwestern India were retrospectively analyzed to assess their reproductive performance. The overall per cycle pregnancy rate at Day 16 and overall foaling rates were 50.30% and 68.95%, respectively, and were significantly higher in mares aged 3-7 years than > or =18 years old mares. The late embryonic losses (9.86%) that occurred between Days 16 and 39 post-ovulation contributed more than 50% of the overall detected pregnancy losses (19.1...
Synthesis and characterization of biologically active recombinant elk and horse FSH. The objective of this investigation was to clone and express the elk and horse common alpha-subunit and FSH beta-subunit cDNAs, and to produce recombinant FSH from both species in vitro. The RNAs extracted from elk and horse pituitary glands were reverse-transcribed and amplified by polymerase chain reaction. The cDNAs corresponding to both subunits of elk and horse were cloned into the expression vector pBudCE4.1 and transfected into CRL-9096 cells. Expression of both genes was determined in the transfected cells by Northern and Western blot analysis. Recombinant elk and horse FSH secreted in...
Differential luteolytic function between the physiological breeding season, autumn transition and persistent winter cyclicity in the mare. There is a well-documented increase in luteolytic failure, resulting in spontaneously prolonged corpus luteum (SPCL) function, during estrous cycles of horses in autumn. The cause of this phenomenon may be due to seasonal alterations in PGF(2alpha) and/or in prolactin (PRL) secretion around luteolysis. To investigate this, progesterone (P4), 13, 14-dihydro, 15-keto PGF(2alpha) (PGFM) and PRL concentrations were compared between summer and autumn estrous cycles during natural luteolysis and luteolysis induced by benign uterine stimulation. A single estrous cycle from mares in June-July (n=12) w...
Factors influencing conception rates of Arab mares in Tunisia. In order to investigate the factors affecting the reproduction efficiency of Arab breeding mares in Tunisia, breeding data corresponding to 2340 mated cycles, over 5 years (from 2000 to 2004), from 555 mares offspring of 50 sires and bred with 17 stallions were analysed using a multivariate logistic regression. We chose logit link function and binomial distribution and we used log-likelihood-ratio (LL) and Wald tests (X(2)Wald) to test the mean values. The factors of variation included in the model were the year, the stallion, the age of the mare at mating, the sire and the category of the mar...
Disruption of the periovulatory LH surge by a transient increase in circulating 17beta-estradiol at the time of ovulation in mares. The mechanism for a reported temporal association between ovulation and a transient disruption in the periovulatory increase in LH concentrations was studied in nine mares treated with human chorionic gonadotropin when the preovulatory follicle was >/=32mm. Examinations for ovulation detection and blood collection were done at 2-h intervals and the results were retrospectively centralized to ovulation (Hour 0). Concentrations of LH began to increase (P<0.03) rapidly at Hour -18, decreased (P<0.04) between Hours 0 and 6, and again increased (P<0.0001) after Hour 12. A progressive de...
Prostaglandin H synthase Type 2 is differentially expressed in endometrium based on pregnancy status in pony mares and responds to oxytocin and conceptus secretions in explant culture. The equine embryo must signal its presence to the uterus for pregnancy to continue to term. Mobility of the conceptus throughout the uterus is crucial for its survival, and this action presumably permits the conceptus to transmit its antiluteolytic signal to the endometrium. Studies were completed to establish whether this unidentified antiluteolytic signal targets prostaglandin G/H synthase 2 (PGHS2), a rate limiting enzyme in converting arachidonic acid to prostaglandins (PGs). In the first study, quantitative RT-PCR was used to determine the relative abundance of PGHS2 mRNA in endometrium d...
Relation between leptin and estradiol levels in Egyptian lactating Arab mares during foaling heat. Sixteen Arab lactating mares belonging to Al-Zahraa Arab Horse Stud underwent two ultrasound examinations at 3 weeks interval starting from the day of demonstration of foaling heat. In addition, daily blood samples were collected from parturition until after exhibiting first postpartum estrus (day 11) with daily observation of estrous signs. Both leptin and estradiol hormones were assayed. Mean day of foaling heat was 8.9+/-0.9 day. Most mares came in foaling heat during days 9 and 10 had high conception rate compared to those who came in estrus earlier or later. Estradiol levels were high aft...
The efficacy of recombinant equine follicle stimulating hormone (reFSH) to promote follicular growth in mares using a follicular suppression model. The efficacy of a recently engineered single chain recombinant equine follicle stimulating hormone (reFSH) was investigated in estrous cycling mares whose gonadotropins and follicular activity had been suppressed by concurrent treatment with progesterone and estradiol (P&E). Time of estrus was synchronized in 15 estrous cycling mares during the breeding season with prostaglandins F(2alpha) (PGF(2alpha)). The day after ovulation, mares were treated once daily with P&E for 14 days. Mares received a second injection of PGF(2alpha) on day 6 of the synchronized estrous cycle to induce luteolysis. O...
Colloidal centrifugation with Androcoll-E prolongs stallion sperm motility, viability and chromatin integrity. The objective was to investigate the changes in stallion sperm quality (sperm motility, viability, membrane integrity and chromatin integrity) occurring during cool storage, and to study the effect of sperm selection by single layer colloidal centrifugation on these parameters of sperm quality. Spermatozoa from 3 stallions (10 ejaculates, 3-4 per stallion) were selected by centrifugation through a single layer of colloid (SLC). The resulting sperm preparations and the control samples (extended but unselected semen samples) were stored at 5 degrees C for 48h. Assessments of sperm quality, such ...
Maternal age and parity influence ultrasonographic measurements of fetal growth in Dutch Warmblood mares. Ultrasonographic examination of the equine fetus in mid-late gestation is usually performed only if there are concerns about fetal or maternal health. Even then it is difficult to determine whether development is 'normal' for gestational age because the reference values include considerable error margins. This study examined maternal factors that influence fetal growth with the aim of producing more precise late gestation fetal growth curves for Dutch Warmblood horses. Fetal development was monitored at 2-week intervals from day 100 of gestation until term in 32 mares ranging from 4 to 18 year...
Reproductive performance of donor mares subsequent to eFSH treatment in early vernal transition: Comparison between the first, second, and mid-season estrous cycles of the breeding season. The objective was to compare the reproductive performances associated with the first (Cycle-1), second (Cycle-2), and mid-season (MS-Cycle) ovulations of the breeding season in donor mares that were treated with equine-FSH (eFSH) in the early vernal transition. Mares (n=15) kept under ambient light were examined ultrasonographically per-rectum starting January 30. When an ovarian follicle > or =25mm in diameter was detected, twice daily eFSH treatments were initiated. The eFSH treatments ceased when a follicle > or =35mm was detected, and 36h later hCG was administered. Thereafter, mares were ...
Microbial quality of equine frozen semen. Bacteriological surveillance is little applied in management of equine frozen semen but it is quite important to verify the microbial contamination in order to find out the chance of transmission of pathology to the mare in AI. Authors describe a qualitative and quantitative analysis for bacterial contamination on long time (3-17 years) equine frozen semen stored in liquid nitrogen. The semen checked, produced in Italy and in another Europe country, was cryopreserved in liquid nitrogen inside sealed plastic straws. One hundred and ten straws were checked out for pathogenic and no pathogenic ba...
Suppression of testicular function and sexual behavior by vaccination against GnRH (Equity) in the adult stallion. The aim of this study was to evaluate the effects of an anti-GnRH vaccine on testosterone concentration, antibody titer, scrotal width, semen quality and sexual behavior in the stallion. Adverse reactions to the vaccine were also determined. Eight clinically healthy sexually experienced stallions aged between 6 and 15 years from the National Stud in Avenches (Switzerland) were used. Five stallions were immunized 3 times at an interval of 4 and 8 weeks, respectively, with 200 microg of a GnRH-protein conjugate (Equity, CSL Limited, Australia) intramuscularly in the neck and 3 control animals re...
Early effects of equine FSH (eFSH) treatment on hormonal and reproductive parameters in mares intended to carry their own pregnancy. Superovulatory treatment may potentially increase the embryo recovery rate and the per-cycle pregnancy rate in normal or subfertile mares that are managed properly. However, some studies suggest a possible negative effect of superovulatory treatment on ovarian follicular maturation and embryo viability. Objectives of the present study were to investigate the early effects of eFSH treatment in reproductively normal mares in terms of: folliculogenesis, pregnancy rate, early embryonic development, reproductive tract parameters (tone and edema), and serum estradiol-17beta and progesterone concentr...
Species-specific interaction of seminal plasma on sperm-neutrophil binding. Bovine semen is naturally deposited in the vagina and spermatozoa migrate through the cervix into the uterus leaving the bulk of seminal plasma (SP) behind. In equine, both spermatozoa and SP are deposited directly in the uterus and SP reduces sperm binding to neutrophils and prevents the formation of DNA-based neutrophil extracellular traps (NETs). We investigated the role of bovine SP on sperm-neutrophil binding using the four most common bovine semen extenders. Contrary to equine, bovine spermatozoa removed from SP had low binding to neutrophils for up to 3h, but as little as 10% SP increas...
Apoptotic markers can be used to forecast the freezeability of stallion spermatozoa. In an attempt to identify valuable markers for potential freezeability of the equine spermatozoa, three ejaculates were collected from five Andalusian stallions and frozen using a standard protocol. Before freezing, three apoptotic cell markers were studied by flow cytometry (early changes in sperm membranes, mitochondrial membrane potential and caspase activity). Post-thaw, spermatozoa were again evaluated for these parameters. Sperm kinematics using CASA were also studied before and after freezing and thawing. Receiving operating system curves were used to evaluate the relative value of the ...