Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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 |
Components in seminal plasma regulating sperm transport and elimination. Seminal plasma has been suggested to be involved in sperm transport, and as a modulator of sperm-induced inflammation, which is thought to be an important part of sperm elimination from the female reproductive tract. This article reports on recent experiments on the importance of seminal plasma components in sperm transport and elimination. In Experiment 1, hysteroscopic insemination in the presence (n = 3) or absence (n = 3) of 2 ng/mL PGE showed an increased portion of spermatozoa crossing the utero-tubal junction in the presence of PGE in two mares, while no difference was observed between ...
Amides as cryoprotectants for freezing stallion semen: a review. Stallion semen cryopreservation, despite its impact on the horse industry, is not an established technology. During the last years, a number of modifications have been proposed to the freezing process, however, a large population of stallions still have poor semen quality and fertility after frozen-thawed. Glycerol toxicity could be a reason for the variation on stallion sperm freezability. There are limited publications concerning the use of alternative cryoprotectants for equine sperm. Glycerol is contraceptive for some species and other cryoprotectors, such as amides, have been show to be a...
Challenges facing sex preselection of stallion spermatozoa. Since the production of the first live offspring from sex-sorted spermatozoa in 1989, there have been many developments in the fluorescence-activated cell separation (FACS) procedures to preselect X- and Y-chromosome bearing spermatozoa prior to insemination. During this time, FACS technology has been applied to a range of species and has resulted in offspring from rabbits, cattle, sheep, elk and horses. In horses, satisfactory fertility rates have been achieved after hysteroscopic insemination of 20 x 10(6) fresh or stored, sex-sorted spermatozoa. However, many of the sperm processing protoco...
A comparison of the effects of equine luteinizing hormone (eLH), equine growth hormone (eGH) and human recombinant insulin-like growth factor (hrIGF-I) on steroid production in cultured equine Leydig cells during sexual maturation. There are several hormones and local testicular factors involved in the initiation and control of steroidogenesis and spermatogenesis during puberty. GH and its mediator, IGF-I, increase substantially during puberty, and in addition to LH, these growth-promoting hormones can have direct effects upon testicular function. The objective of this work was to investigate the effects of eLH, eGH and hrIGF-I upon Leydig cells derived from testes of colts and stallions representing different stages of development. Testes were obtained from 48 light horse colts and stallions at the time of routine castr...
Integration of future biotechnologies into the equine industry. There has and will continue to be reproductive techniques available that have a positive impact upon the equine breeding industry. This review focuses on semen technologies that have been developed or are in the process of being developed. The use of fluorescent dyes and flow cytometry has provided the researcher and clinician with powerful tools to evaluate several sperm attributes. These procedures have been utilized to evaluate sperm viability, acrosome status, mitochondrial status, DNA integrity and stages of capacitation. Flow cytometry allows several sperm attributes to be evaluated on t...
Factors affecting the plasma membrane function of cooled-stored stallion spermatozoa. The spermatozoon is a highly specified cell that has the abilities of active motility and fertilization of the ovum. Damage to the sperm plasma membrane results in the irreversible loss of its functions. Because of the high content of unsaturated fatty acids in the plasma membrane, mammalian sperm are sensitive to oxidative stress. While mild peroxidation appears to promote capacitation of the sperm cell, excessive peroxidation will damage the plasma membrane and results in loss of motility and fertility. The functional integrity of the sperm plasma membrane can be determined by functional tes...
Effect of the inseminate and the site of insemination on the uterus and pregnancy rates of mares. In this review, effects of the composition of the inseminate on uterine response and pregnancy rates in mares are discussed. The inseminate can differ for volume, sperm concentration, total sperm numbers, presence, absence, or proportion of seminal plasma, and extender composition. Semen can be used as fresh, cooled, or frozen. The site of semen deposition also plays a role; semen is deposited either into the uterine body (standard artificial insemination (AI)) or into the tip of the uterine horn ipsilateral to the preovulatory follicle (deep AI) using the hysterocopical or transrectally guide...
Modulating reproductive activity in stallions: a review. Situations in which suppression or stimulation of reproductive activity in stallions has been attempted, or is desired, include resolution of the equine arteritis virus 'shedding' state, induction of testicular descent in inguinal cryptorchids, and the improvement of sperm production capacity and/or semen quality in sub-fertile stallions. However, the most common reason for wanting to modulate reproductive activity in a stallion is to alter the expression of sexual behaviour. In the case of intact stallions used for competitive or recreational purposes, the overt expression of sexual or aggres...
Genetic markers for stallion fertility–lessons from humans and mice. Our knowledge on the many aspects of mammalian reproduction in general and equine reproduction in particular has greatly increased during the last 15 years. Advances in the understanding of the physiology, cell biology, and biochemistry of reproduction have facilitated genetic analyses of fertility. Currently, there are more than 200 genes known that are involved in the production of fertile sperm cells. The completion of a number of mammalian genome projects will aid in the investigation of these genes in different species. Great progress has been made in the understanding of genetic aberrati...
Capacitation, acrosome function and chromatin structure in stallion sperm. In general, fertility in breeding stallions is lower and more variable than in the other farm animal species, primarily because selection is based on pedigree, looks and/or athletic performance, with little consideration of fertility or fertility potential. Moreover, because the average stallion breeds only a limited number of mares per year and in-field fertility is influenced significantly by non-stallion factors such as management and mare fertility, meaningful fertility data are hard to come-by. Unfortunately, generating usable figures would involve impractically high costs, time and numbe...
Advanced fertility diagnosis in stallion semen using transmission electron microscopy. Routine semen analysis of stallions is based on light microscopy (LM). However, there are still a number of animals that are subfertile or even infertile not being identified with conventional semen analysis. The objective of this study was to investigate the suitability of transmission electron microscopy (TEM) for advanced fertility diagnosis in stallion. We examined ejaculates of 46 stallions with known fertility. Animals were divided into three different groups: group 1, fertile stallions (pregnant mares> or =70%, n=29); group 2, subfertile stallions (pregnant mares 10-69%, n=14); group...
Effect of alpha-tocopherol and tocopherol succinate on lipid peroxidation in equine spermatozoa. The objective of this study was to compare the effect of alpha-tocopherol and its ester, alpha tocopherol succinate, on lipid peroxidation and motility of equine spermatozoa. In experiment one, spermatozoa were incubated with dl-alpha-tocopherol (5, 25, 100 or 500 microM), DL-alpha tocopherol succinate (5, 25, 100 or 500 microM) or vehicle (0.5% ethanol) at 38 degrees C, and sperm motility was determined at 30, 60 and 120 min. In experiment two, spermatozoa loaded with the lipophilic probe, C11BODIPY(581/591), were incubated with dl-alpha-tocopherol (50 and 100 microM), DL-alpha-tocopherol suc...
LH and IGF-1 release during oestrus and early luteal phase in lactating and non-lactating horse mares. The aim of the present study was to determine effects of lactation on basal LH and IGF-1 concentrations and on the LH response to a GnRH-analogue at different stages of the oestrous cycle in mares. A total of 17 cyclic Haflinger mares were included in the study. Experiments were performed on lactating mares in first postpartum oestrus, the subsequent early luteal phase, and second postpartum oestrus. Non-lactating mares were used in oestrus and early luteal phase. Blood samples were taken for 1 h at 15 min intervals. Mares were then injected with the GnRH-analogue buserelin (GnRHa; 5 microg i....
Effects of GnRH immunization in sexually mature pony stallions. Immunization against gonadotrophin releasing hormone (GnRH) was studied as an alternative for the commonly used surgical castration in stallions. Two GnRH vaccines comprising non-mineral oil adjuvants were evaluated for their potential to induce high antibody titers directed against GnRH and subsequent effects on reproductive characteristics. Twelve sexually mature male hemicastrated Shetland ponies were assigned to three groups. Group 1 and 2 were injected with 1mg peptide equivalent of G6k-GnRH-tandem-dimer conjugated to ovalbumin (OVA) in CoVaccine HT adjuvant (GnRH/CoVaccine) and in Carbop...
Stage-specific formation of the equine blastocyst capsule is instrumental to hatching and to embryonic survival in vivo. Early embryonic development in the horse is characterized by the formation of an unusual acellular glycoprotein "capsule" between the trophectoderm and the overlying zona pellucida. This structure is first detected between days 6 and 7 after ovulation and completely envelops the spherical conceptus until as late as day 23 of gestation. In the present study, a micromanipulator was used to remove the capsule from 15 embryos on day 6-7 after ovulation. None of these denuded embryos developed into ultrasonographically detectable pregnancies after surgical transfer into recipient mares whereas four...
Relationships between sexual behaviour, dominant follicle area, uterus ultrasonic image and pregnancy rate in mares of two breeds differing in reproductive efficiency. Weak or equivocal expression of oestrous behaviour, related to different level of mares' reactivity, may cause problems in oestrus detection and thus influence the reproductive efficiency. The aim of the study was to test whether a breed characterised by low pregnancy rate and high emotional reactivity (Thoroughbreds) differs in oestrous behaviour from a primitive breed with higher reproductive efficiency (Koniks). Additionally, the follicle size was examined to determine how it influences the intensity of oestrus and uterine ultrasonic image and whether the pregnancy rate differs in relation ...
Hysteroscopic or rectally guided, deep-uterine insemination of mares with spermatozoa stored 18 h at either 5 degrees C or 15 degrees C prior to flow-cytometric sorting. Practical application of sex-selected spermatozoa in the horse industry would be greatly improved by the ability to develop simplified methods for shipping, storing, and inseminating sex-selected spermatozoa. Acceptable pregnancy rates have been achieved using fresh sex-sorted stallion sperm, however many stallion owners are reluctant to send their stallions to the sorter location for collection during the breeding season. Furthermore, the technology would be more applicable if the hysteroscopic insemination technique was not necessary for adequate pregnancy rates. Hysteroscopic insemination r...
Step-wise dilution for removal of glycerol from fresh and cryopreserved equine spermatozoa. Osmotic stress is an important component of the damage to spermatozoa during cryopreservation. Osmotic injury, due to hyperosmolar freezing extenders, changes in relative solute concentration in the extra cellular medium during freezing and differences in the relative permeabilities of penetrating cryoprotectants, such as glycerol, and water occur when cryopreserved spermatozoa are diluted into isosmotic media or when spermatozoa are placed in the female reproductive tract. The purpose of the study reported here was to evaluate the effect of step-wise dilution for the removal of the permeating...
Suppressing reproductive activity in horses using GnRH vaccines, antagonists or agonists. There are a number of situations in which it is desirable to suppress part or all of the reproductive endocrine system in a horse, notably the competing animal whose tractability during training, or performance during competition, is compromised by the expression of sexual or aggressive behavior. The current therapeutic approaches to reproductive endocrine suppression include gonadectomy and progestagen administration, where the former carries surgical risks and entails irreversible loss of breeding potential, and effective progestagen therapy requires frequent administration for extended peri...
Integration of sperm sexing technology into the ART toolbox. Sex-sorting of mammalian spermatozoa has applications for genetic improvement of farm animals, in humans for the control of sex-linked disease, and in wildlife as a captive management strategy and for the re-population of endangered species. Considerable research has been undertaken worldwide on the Beltsville sperm sexing technology, the only effective method for pre-selection of sex of offspring. The combination of this method with assisted reproductive technologies has resulted in the birth of offspring in a wide range of animals, including cattle, the only livestock species in which sperm ...
Low dose insemination in the mare: an update. The generally recommended minimum number of spermatozoa required for conventional artificial insemination in the mare is in excess of 200 x 10(6) progressively motile spermatozoa. Recent developments in different insemination techniques such as deep uterine, hysteroscopic and oviductal insemination, which have been designed to use significantly fewer spermatozoa, are reviewed in this paper. A number of studies have demonstrated that ultrasound guided deep uterine insemination of 5 x 10(6) fresh spermatozoa can produce satisfactory pregnancy rates. The use of hysteroscopic insemination enables ...
Oocyte transfer and gamete intrafallopian transfer in the mare. Methods for the collection and transfer of equine oocytes have been developed, and uses of these techniques have resulted in new clinical and research possibilities. Because oocyte transfer avoids reproductive problems associated with the oviduct, uterus, and cervix, pregnancies can be produced from many mares that cannot carry a pregnancy or produce embryos. Oocytes for clinical transfers are usually collected from preovulatory follicles and cultured for a short interval or transferred directly into a recipient's oviduct. For oocyte transfer, the recipient is inseminated within the uterus. A ...
Ultrasonic characteristics of preovulatory follicle and ovulation in Caspian mares. The Caspian breed of horses is believed to be the direct descendant of the earliest equine animals. Some special characteristics of Caspian horse differentiate this breed of horses from other breeds. In the current study the ultrasonically observed characteristics of a preovulatory dominant follicle and the lengths of estrus, diestrus as well as some related parameters were studied during 42 interovulatory intervals in 11 healthy Caspian mares. The preovulatory dominant follicle deviated from subordinate follicles and became the largest follicle in the ovaries at Day -8.7 +/- 0.53 (Day 0=ovula...
Matrix metalloproteinase-2 and -9 secretion by the equine ovary during follicular growth and prior to ovulation. Profound hormonally controlled tissue remodelling occurs in the equine ovary for follicle growth and development, and also for the alteration in follicle shape directed towards the ovulation fossa, the site where ovulation occurs. The aim of this study was to examine the spatial and temporal regulation of matrix metalloproteinases (MMP)-2 and MMP-9, important enzymes in tissue remodelling, during follicle growth, and ovulation. Using gelatin substrate zymography, we measured these MMPs in follicular fluid of large anovulatory follicles collected during spring transition, early dominant follicl...
Pregnancy outcome in mares following insemination deep in the uterine horn with low numbers of sperm selected by glass wool/Sephadex filtration, Percoll separation or absolute number. Mares were inseminated deep in the uterine horn with 25 million sperm selected by glass wool/Sephadex (GWS) filtration, Percoll separation (PS) or absolute number (AN). Deep-horn insemination using a low-volume, smooth tipped, flexible pipette/catheter delivery system allowed more efficient use of stallion sperm and reduced post-breeding uterine reaction in mares. Mares were pregnant in 15/30, 13/30 and 10/30 cycles for GWS, PS and AN selection methods, respectively. Sperm selection method did not effect pregnancy outcome (P=0.422). However, sperm selected for deep-horn insemination by filtrat...
Mechanism of follicle deviation in monovular farm species. Diameter deviation is a distinctive change in growth rates among the follicles of a wave, heralding the formation of a dominant follicle and subordinate follicles. When the follicles are about 5mm in cattle and 13 mm in horses, the wave-stimulating FSH surge reaches peak concentrations. Follicle and FSH manipulation studies in both species have shown that the declining portion of the surge before the beginning of deviation is a function of multiple growing follicles that require the decreasing FSH. During this time, all follicles of the wave have the potential for future dominance. Deviation b...
Seasonal changes of semen quality and freezability in Franches-Montagnes stallions. The objective of this study was to investigate seasonal changes of semen quality parameters in Franches-Montagnes stallions and to compare the freezability of ejaculates collected in autumn and winter. Experiments were performed using 15 stallions from the National Stud Farm in Avenches (Switzerland). Ejaculates were collected and evaluated every month during 1 year as well as cryopreserved in autumn and winter (September to February). In fresh semen the gel-free volume, concentration, motility and morphology (normal sperm, major defects, vacuoles and acrosome defects) were evaluated and in fr...
Effect of daily clenbuterol and exogenous melatonin treatment on body fat, serum leptin and the expression of seasonal anestrus in the mare. A small percentage of mature mares continue to exhibit estrous cyclicity during the non-breeding season which is of interest because of the importance of timing of the breeding season to the equine breeding industry. Previously, it was demonstrated that the continuation of estrous cycles was more likely to occur in mature than young mares. Additionally, an apparent association exists between elevated body fat and increased circulating concentrations of leptin, and the occurrence of estrous cycles during the non-breeding season. Two experiments were conducted to test the hypothesis that pharmac...
Evaluation of cryopreserved stallion semen from Tori and Estonian breeds using CASA and flow cytometry. Methods to evaluate the quality of frozen-thawed stallion semen are still needed, particularly those considering the sperm function. The present study evaluated sperm motility, membrane and acrosome integrity and the capacitation status of frozen-thawed spermatozoa from seven Tori and six Estonian breed stallions by way of computer assisted sperm analysis (CASA), a triple fluorophore stain combination and Merocyanine 540, respectively, the latter ones using flow cytometry. Two ejaculates from each stallion were cryopreserved using the Hannover method in 0.5 ml plastic straws. Two straws per ej...
