Prostaglandin F2α and its analogues (PGF) are widely used in equine reproductive practice. The in... more Prostaglandin F2α and its analogues (PGF) are widely used in equine reproductive practice. The interval from PGF treatment to ovulation (ITO) varies greatly with a range from 2 to 16 days. Clinical observation suggests that mares mated and ovulated soon after PGF treatment may have poor fertility. Reproductive records of 329 cyclic Thoroughbred mares were analysed retrospectively. The following parameters were analysed: (i) use of cloprostenol; (ii) ITO and (iii) number of ovulations per cycle. According to these parameters, mares were classified into four groups. (i) mares with spontaneous ovulations, n = 57; (ii) mares induced with cloprostenol and ITO = 4–7 days, n = 77; (iii) ITO = 8–10 days, n = 89 and (iv) ITO = ≥11 days, n = 106. Differences in pregnancy (PR) and multiple ovulation (MO) rates among groups were tested using chi-squared test. PR rates for groups 1–4 were: 73.7%, 46.7%, 64% and 71.7% respectively (p < 0.05). Groups 1 and 2 had lower (p < 0.05) MO rate (24.6% and 20.8%) than groups 3 and 4 (40.4% and 44.3%). It appears that ovulation soon after PGF-induced luteolysis is detrimental to PR rates. It was found highly significant that in cloprostenol-treated mares, the MO rate was enhanced without subsequent increase in multiple pregnancies.
A combined suppressive effect of prolactin (PRL) and dopamine on the secretion of luteinising hor... more A combined suppressive effect of prolactin (PRL) and dopamine on the secretion of luteinising hormone (LH) at the level of the pituitary gland has been identified in sheep, a short-day breeder. However, little is known about the role of PRL in the intra-pituitary regulation of the gonadotrophic axis in long-day breeders. In the present study, we investigated the effects of PRL on LH and follicle-stimulating hormone (FSH) secretion during the equine annual reproductive cycle. Horse pituitaries were obtained during the breeding season (BS) and nonbreeding season (NBS). Cells were dispersed, plated to monolayer cultures and assigned to one of the following specific treatments: (i) medium (Control); (ii) rat PRL (rPRL); (iii) thyrotrophin-releasing hormone (TRH); (iv) bromocriptine (Br); and (v) Br + rPRL. Gonadotrophin-releasing hormone (GnRH) dose-dependently stimulated LH release during the BS and NBS. During the BS, neither rPRL nor TRH affected the LH response to GnRH, but Br significantly (P < 0.01) enhanced both basal and GnRH-stimulated LH release through a mechanism that did not involve alterations in the concentrations of PRL. However, rPRL prevented the Br-induced increase in basal and GnRH-stimulated LH output, and suppressed LH below basal values (P < 0.05). Conversely, during the NBS, no significant effects of treatments were observed. Interestingly, at this time of year, the incidence of pituitary gap junctions within the pars distalis decreased by 50% (P < 0.01). By contrast to the effects on LH, no treatment effects were detected on the FSH response to GnRH, which was only apparent during the NBS. These results reveal no direct effects of PRL but an interaction between PRL and dopamine in the inhibitory regulation of LH, but not FSH, release at the level of the pituitary in the horse, and a modulatory role of season/photoperiod associated with alterations in folliculostellate cell-derived gap junctions.
The objective was to evaluate deficits and differences of published literature on reproduction in... more The objective was to evaluate deficits and differences of published literature on reproduction in cattle, horses, and dogs. A literature search was conducted in the databases Medline and Veterinary Science. Approximately five times more articles on clinical bovine reproduction (n = 25 910) were found compared to canine (n = 5 015) and equine (n = 5 090) reproduction. For the evaluation of the literature, a checklist was used. A subset of 600 articles published between 1999 and 2008 was randomly selected. After applying exclusion criteria, a total of 268 trials (86 for cattle, 99 for horses, and 83 for dogs) were evaluated and used for further analysis. For the field of canine and equine reproduction, there were fewer clinical trials with a control group compared to bovine reproduction (cattle 66%, horses 41%, and dogs 41%). For all three species investigated, few publications were identified (4%) with the highest level of evidence, i.e., controlled, randomized, and blinded trials, or meta-analyses. In cattle 33% of the publications were graded adequate to draw sound conclusions; however, only 7 and 11% were graded adequate in dogs and horses, respectively. Therefore, the veterinarian should always assess the quality of information before implementing results into practice to provide best available care for the animals. In conclusion, improvement of the quality of well-designed, conducted and reported clinical trails in animal reproduction is required.
In the past four decades there have been tremendous changes in equine reproduction. Most breeds n... more In the past four decades there have been tremendous changes in equine reproduction. Most breeds now allow the use of artificial insemination with fresh, cooled and frozen semen. Artificial insemination has many advantages for the breeder, in particular the control of bacteria through the use of semen extenders containing antibiotics. Deposition of sperm in small volumes onto the uterotubal junction has allowed the use of relatively low numbers of sperm. Intracytoplasmic injection of sperm into oocytes allows older, subfertile stallions to be used as breeding stallions. Advances in mare reproduction have included developing tools for hastening the onset of the breeding season. Other advances include embryo transfer, oocyte collection and transfer, and cloning. The acceptance of reproductive technology depends on the success of the technology, the attitude of the breeders/veterinarians, and the cost/benefit ratio to the industry and breed registry.
SUMMARYMares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova a... more SUMMARYMares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova accumulate in the oviducts of unserved mares. During pregnancy, corpora lutea accumulate; all regress together at mid pregnancy. Plasma progesterone levels rise and oestrogen levels fall towards the end of pregnancy. Methods are available for early termination of pregnancy and for induction of parturition. Pregnancy can be diagnosed efficiently by rectal examination, and by immunological assay of pregnant mare serum gonadotrophin. Service at the foal heat is associated with an increased prevalence of early embryonic death; twinning is the commonest single cause of abortion. Spontaneous prolonged dioestrus is common in summer but may be effectively treated.Bacterial endometritis may result mainly from secondary pathogenic activity by organisms of the normal uterine flora; diagnosis by endometrial smear examination is accurate and methods of treatment have improved. The virus of horse pox has been identified, and the occurrence of equine infection with Mycoplasma has been confirmed.In the male, recent work has emphasized that reproductive function is seasonal. The presence or absence of an undescended testis can now be accurately determined.Mares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova accumulate in the oviducts of unserved mares. During pregnancy, corpora lutea accumulate; all regress together at mid pregnancy. Plasma progesterone levels rise and oestrogen levels fall towards the end of pregnancy. Methods are available for early termination of pregnancy and for induction of parturition. Pregnancy can be diagnosed efficiently by rectal examination, and by immunological assay of pregnant mare serum gonadotrophin. Service at the foal heat is associated with an increased prevalence of early embryonic death; twinning is the commonest single cause of abortion. Spontaneous prolonged dioestrus is common in summer but may be effectively treated.Bacterial endometritis may result mainly from secondary pathogenic activity by organisms of the normal uterine flora; diagnosis by endometrial smear examination is accurate and methods of treatment have improved. The virus of horse pox has been identified, and the occurrence of equine infection with Mycoplasma has been confirmed.In the male, recent work has emphasized that reproductive function is seasonal. The presence or absence of an undescended testis can now be accurately determined.RÉSUMÉLes juments ovulent rarement en hiver; l'ovulation est induite par l'augmentation de la lumière du jour. Les oeufs s'accumulent dans les oviductes chez les juments non saillies.Durant la gestation les corps jaunes s'accumulent: ils régressent tous ensemble vers le milieu de la gestation.Le taux plasmastique de progesterone s'élève et le taux d'oestrogène s'abaisse à la fin de la gestation.Il existe des méthodes pour déterminer précocement la gestation et pour induire la mise bas.La gestation peut être diagnostiquée efficacement par palpation transrectable et par détermination immunologique du taux de PMSG. La saillie sur la chaleur de poulinage a pour conséquence un accroissement du nombre des résorptions embryonnaires précoces.La gemelliparité est la cause simple la plus fréquente des avortements. Un dioestrus spontané prolongé est fréquent en été mais peut être facilement traité.Il est possible que les endométrites bactériennes soient dues essentiellement à une activité secondaire pathogène de la flore utérine normale. Le diagnostic par frottis de l'endometre est efficace et les méthodes de traitement ont été améliorées.Le virus du Horse Pox a été identifié; l'existence de l'infection par des Mycoplasmes a été confirmée.Chez le mâle de récents travaux ont démontré que l'activité sexuelle est saisonnière. La présence ou l'absence d'un testicule inapparent peut être efficacement déterminée.Les juments ovulent rarement en hiver; l'ovulation est induite par l'augmentation de la lumière du jour. Les oeufs s'accumulent dans les oviductes chez les juments non saillies.Durant la gestation les corps jaunes s'accumulent: ils régressent tous ensemble vers le milieu de la gestation.Le taux plasmastique de progesterone s'élève et le taux d'oestrogène s'abaisse à la fin de la gestation.Il existe des méthodes pour déterminer précocement la gestation et pour induire la mise bas.La gestation peut être diagnostiquée efficacement par palpation transrectable et par détermination immunologique du taux de PMSG. La saillie sur la chaleur de poulinage a pour conséquence un accroissement du nombre des résorptions embryonnaires précoces.La gemelliparité est la cause simple la plus fréquente des avortements. Un dioestrus spontané prolongé est fréquent en été mais peut être facilement traité.Il est possible que les endométrites bactériennes soient dues essentiellement à une activité secondaire pathogène de la flore utérine normale. Le diagnostic par frottis de l'endometre est efficace et les méthodes de traitement ont été améliorées.Le virus du Horse Pox a été identifié; l'existence de l'infection par des Mycoplasmes a été confirmée.Chez le mâle de récents travaux ont démontré que l'activité sexuelle est saisonnière. La présence ou l'absence d'un testicule inapparent peut être efficacement déterminée.ZUSAMMENFASSUNGStuten ovulieren im Winter selten; die Ovulation wird induziert durch die Verlängerung der Tageslichtdauer. Bei nicht belegten Stuten akkumulieren sich Eier in den Eileitern. Während der Trächtigkeit sammeln sich auch Gelbkörper an, die sich dann alle miteinander etwa Mitte der Trächtigkeit zurückbilden. Die Plasma-Progesteronspiegel steigen gegen das Ende der Trächtigkeit an, während die Oestrogenspiegel abfallen. Es gibt verschiedene Methoden für einen vorzeitigen Abbruch der Trächtigkeit und die Einleitung der Geburt. Die Trächtigkeit wird diagnostiziert durch die rektale Untersuchung oder auch den immunologischen Nachweis von PMSG. Die Belegung in der Fohlenrosse wird von häufigerem embryonalem Frühtod gefolgt; Zwillingsträchtigkeiten gelten als häufigste Abortursache. Ein spontaner, verlängerter Dioestrus kommt im Sommer häufig vor, kann aber leicht behandelt werden.Bakterielle Endometritiden können hervorgehen aus einer sekundär-pathogenen Aktivität der normalen Uterusflora; die Diagnose aufgrund eines Endometrium-Abstriches ist zuverlässig; die Behandlungsmethoden sind verbessert worden. Das Virus der Pferdepocken konnte identifiziert werden und das Auftreten von Mycoplasma-infektionen bestätigt.Beim Hengsten wurde in neueren Untersuchungen ebenfalls eine jahreszeitliche Abhängigkeit der Fort-pflanzungsfunktionen beobachtet. Das Vorliegen oder das Fehlen nicht deszendierter Hoden kann jetzt genau bestimmt werden.Stuten ovulieren im Winter selten; die Ovulation wird induziert durch die Verlängerung der Tageslichtdauer. Bei nicht belegten Stuten akkumulieren sich Eier in den Eileitern. Während der Trächtigkeit sammeln sich auch Gelbkörper an, die sich dann alle miteinander etwa Mitte der Trächtigkeit zurückbilden. Die Plasma-Progesteronspiegel steigen gegen das Ende der Trächtigkeit an, während die Oestrogenspiegel abfallen. Es gibt verschiedene Methoden für einen vorzeitigen Abbruch der Trächtigkeit und die Einleitung der Geburt. Die Trächtigkeit wird diagnostiziert durch die rektale Untersuchung oder auch den immunologischen Nachweis von PMSG. Die Belegung in der Fohlenrosse wird von häufigerem embryonalem Frühtod gefolgt; Zwillingsträchtigkeiten gelten als häufigste Abortursache. Ein spontaner, verlängerter Dioestrus kommt im Sommer häufig vor, kann aber leicht behandelt werden.Bakterielle Endometritiden können hervorgehen aus einer sekundär-pathogenen Aktivität der normalen Uterusflora; die Diagnose aufgrund eines Endometrium-Abstriches ist zuverlässig; die Behandlungsmethoden sind verbessert worden. Das Virus der Pferdepocken konnte identifiziert werden und das Auftreten von Mycoplasma-infektionen bestätigt.Beim Hengsten wurde in neueren Untersuchungen ebenfalls eine jahreszeitliche Abhängigkeit der Fort-pflanzungsfunktionen beobachtet. Das Vorliegen oder das Fehlen nicht deszendierter Hoden kann jetzt genau bestimmt werden.
Veterinary Clinics of North America-equine Practice, Jan 1, 2006
Assisted reproductive techniques have been developed to obtain pregnancies from subfertile mares ... more Assisted reproductive techniques have been developed to obtain pregnancies from subfertile mares and stallions and to salvage gametes after death. In recent years, these procedures have been used for clinical cases with repeated success. Although new developments occur, the basis for the success and future development of assisted reproductive techniques is our ability to collect and handle the equine oocyte successfully. This article focuses on important clinical aspects of oocyte collection and evaluation and briefly discusses the clinical use of assisted reproductive procedures in the horse.
The goal of this review is to provide evidence supporting the physiologic basis for the use of ac... more The goal of this review is to provide evidence supporting the physiologic basis for the use of acupuncture as a treatment in equine reproduction, and to discuss current uses of acupuncture for the treatment of anestrus, urine pooling, uterine infection and/or fluid, infertility, maintenance of pregnancy, cryptorchidism, musculoskeletal pain, and poor libido in stallions. The benefits achieved through acupuncture treatment are thought to be a result of hormonal regulation, altered smooth muscle motility, and general stress and/or pain relief from musculoskeletal or environmental conditions.
The liberalization of European animal breeding legislation and an increasing diversity of equestr... more The liberalization of European animal breeding legislation and an increasing diversity of equestrian sports have led to a constant rise in the number of horse breeds and breed registries. In addition to the trend towards more and smaller breed registries, there is another trend towards an international expansion of the bigger established sport horse breeds. Regional breeds, at least in smaller countries, may no longer be able to run an independent breeding programme. The typical horse breeder, in the future, will be a female and qualified in equestrian sports. Artificial insemination (AI) mainly with fresh or cooled-transported semen has become a major breeding tool, allowing breeders all over Europe to benefit from the best stallions of most breeds. New AI techniques such as low-dose insemination may remain restricted to individual stallions and also the interest of breeding programmes in sex determination of foals via semen sorting is limited. Embryo transfer and associated techniques, although allowed by most breeds, have not contributed significantly to genetic progress in European sport horses so far. A potential use of cloning may be to produce gonad-intact copies from geldings that have performed to a superior level. With a more open and international structure of horse breeding and increased use of AI, equine reproduction and biotechnology should be emphasized by veterinary curricula and continuing professional education programmes.
Doppler ultrasound is an emerging technology that has the potential to increase the diagnostic, m... more Doppler ultrasound is an emerging technology that has the potential to increase the diagnostic, monitoring, and predictive capabilities of equine theriogenologists and researchers. The technology is based on Doppler-shift frequencies, wherein the ultrasound frequency of echoes from moving red cells is increased or decreased as the cells move toward or away from the transducer. In spectral mode, the blood flow in a specific vessel can be assessed by placing a sample-gate cursor on the image of the lumen of the vessel. In addition, an angle cursor can be used to represent the angle of intersection of the ultrasound beams with the direction of blood flow (Doppler angle). The Doppler-shift frequency and the Doppler angle are used by the instrument for computing blood velocity. The focused results from placement of a sample gate in an artery are displayed by a spectrum that represents the changing velocities over time in association with the pulses of cardiac cycles. Peak systolic, end diastolic, and time-averaged maximum velocities are computed and shown for a selected cardiac cycle. Doppler indices (resistance index, RI; pulsatility index, PI) are ratios that are computed from various points on the spectrum. The indices are relatable to the hemodynamics of the tissue supplied by the artery. Increasing RI or PI values indicate increasing resistance and decreasing perfusion of the distal tissues. In color-flow mode, Doppler-shift frequencies are obtained from areas delineated by the operator on the B-mode image and are transformed and expressed as color-coded spots representing areas of blood flow. Vascular perfusion of a structure can be quantitated by the number of colored pixels in an image or can be estimated subjectively by the extent of the colored spots. The Doppler technology has the potential for providing information on the status and future success of a structure. However, realization of the expected potential will depend on future experience and research.
Prostaglandin F2α and its analogues (PGF) are widely used in equine reproductive practice. The in... more Prostaglandin F2α and its analogues (PGF) are widely used in equine reproductive practice. The interval from PGF treatment to ovulation (ITO) varies greatly with a range from 2 to 16 days. Clinical observation suggests that mares mated and ovulated soon after PGF treatment may have poor fertility. Reproductive records of 329 cyclic Thoroughbred mares were analysed retrospectively. The following parameters were analysed: (i) use of cloprostenol; (ii) ITO and (iii) number of ovulations per cycle. According to these parameters, mares were classified into four groups. (i) mares with spontaneous ovulations, n = 57; (ii) mares induced with cloprostenol and ITO = 4–7 days, n = 77; (iii) ITO = 8–10 days, n = 89 and (iv) ITO = ≥11 days, n = 106. Differences in pregnancy (PR) and multiple ovulation (MO) rates among groups were tested using chi-squared test. PR rates for groups 1–4 were: 73.7%, 46.7%, 64% and 71.7% respectively (p < 0.05). Groups 1 and 2 had lower (p < 0.05) MO rate (24.6% and 20.8%) than groups 3 and 4 (40.4% and 44.3%). It appears that ovulation soon after PGF-induced luteolysis is detrimental to PR rates. It was found highly significant that in cloprostenol-treated mares, the MO rate was enhanced without subsequent increase in multiple pregnancies.
A combined suppressive effect of prolactin (PRL) and dopamine on the secretion of luteinising hor... more A combined suppressive effect of prolactin (PRL) and dopamine on the secretion of luteinising hormone (LH) at the level of the pituitary gland has been identified in sheep, a short-day breeder. However, little is known about the role of PRL in the intra-pituitary regulation of the gonadotrophic axis in long-day breeders. In the present study, we investigated the effects of PRL on LH and follicle-stimulating hormone (FSH) secretion during the equine annual reproductive cycle. Horse pituitaries were obtained during the breeding season (BS) and nonbreeding season (NBS). Cells were dispersed, plated to monolayer cultures and assigned to one of the following specific treatments: (i) medium (Control); (ii) rat PRL (rPRL); (iii) thyrotrophin-releasing hormone (TRH); (iv) bromocriptine (Br); and (v) Br + rPRL. Gonadotrophin-releasing hormone (GnRH) dose-dependently stimulated LH release during the BS and NBS. During the BS, neither rPRL nor TRH affected the LH response to GnRH, but Br significantly (P < 0.01) enhanced both basal and GnRH-stimulated LH release through a mechanism that did not involve alterations in the concentrations of PRL. However, rPRL prevented the Br-induced increase in basal and GnRH-stimulated LH output, and suppressed LH below basal values (P < 0.05). Conversely, during the NBS, no significant effects of treatments were observed. Interestingly, at this time of year, the incidence of pituitary gap junctions within the pars distalis decreased by 50% (P < 0.01). By contrast to the effects on LH, no treatment effects were detected on the FSH response to GnRH, which was only apparent during the NBS. These results reveal no direct effects of PRL but an interaction between PRL and dopamine in the inhibitory regulation of LH, but not FSH, release at the level of the pituitary in the horse, and a modulatory role of season/photoperiod associated with alterations in folliculostellate cell-derived gap junctions.
The objective was to evaluate deficits and differences of published literature on reproduction in... more The objective was to evaluate deficits and differences of published literature on reproduction in cattle, horses, and dogs. A literature search was conducted in the databases Medline and Veterinary Science. Approximately five times more articles on clinical bovine reproduction (n = 25 910) were found compared to canine (n = 5 015) and equine (n = 5 090) reproduction. For the evaluation of the literature, a checklist was used. A subset of 600 articles published between 1999 and 2008 was randomly selected. After applying exclusion criteria, a total of 268 trials (86 for cattle, 99 for horses, and 83 for dogs) were evaluated and used for further analysis. For the field of canine and equine reproduction, there were fewer clinical trials with a control group compared to bovine reproduction (cattle 66%, horses 41%, and dogs 41%). For all three species investigated, few publications were identified (4%) with the highest level of evidence, i.e., controlled, randomized, and blinded trials, or meta-analyses. In cattle 33% of the publications were graded adequate to draw sound conclusions; however, only 7 and 11% were graded adequate in dogs and horses, respectively. Therefore, the veterinarian should always assess the quality of information before implementing results into practice to provide best available care for the animals. In conclusion, improvement of the quality of well-designed, conducted and reported clinical trails in animal reproduction is required.
In the past four decades there have been tremendous changes in equine reproduction. Most breeds n... more In the past four decades there have been tremendous changes in equine reproduction. Most breeds now allow the use of artificial insemination with fresh, cooled and frozen semen. Artificial insemination has many advantages for the breeder, in particular the control of bacteria through the use of semen extenders containing antibiotics. Deposition of sperm in small volumes onto the uterotubal junction has allowed the use of relatively low numbers of sperm. Intracytoplasmic injection of sperm into oocytes allows older, subfertile stallions to be used as breeding stallions. Advances in mare reproduction have included developing tools for hastening the onset of the breeding season. Other advances include embryo transfer, oocyte collection and transfer, and cloning. The acceptance of reproductive technology depends on the success of the technology, the attitude of the breeders/veterinarians, and the cost/benefit ratio to the industry and breed registry.
SUMMARYMares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova a... more SUMMARYMares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova accumulate in the oviducts of unserved mares. During pregnancy, corpora lutea accumulate; all regress together at mid pregnancy. Plasma progesterone levels rise and oestrogen levels fall towards the end of pregnancy. Methods are available for early termination of pregnancy and for induction of parturition. Pregnancy can be diagnosed efficiently by rectal examination, and by immunological assay of pregnant mare serum gonadotrophin. Service at the foal heat is associated with an increased prevalence of early embryonic death; twinning is the commonest single cause of abortion. Spontaneous prolonged dioestrus is common in summer but may be effectively treated.Bacterial endometritis may result mainly from secondary pathogenic activity by organisms of the normal uterine flora; diagnosis by endometrial smear examination is accurate and methods of treatment have improved. The virus of horse pox has been identified, and the occurrence of equine infection with Mycoplasma has been confirmed.In the male, recent work has emphasized that reproductive function is seasonal. The presence or absence of an undescended testis can now be accurately determined.Mares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova accumulate in the oviducts of unserved mares. During pregnancy, corpora lutea accumulate; all regress together at mid pregnancy. Plasma progesterone levels rise and oestrogen levels fall towards the end of pregnancy. Methods are available for early termination of pregnancy and for induction of parturition. Pregnancy can be diagnosed efficiently by rectal examination, and by immunological assay of pregnant mare serum gonadotrophin. Service at the foal heat is associated with an increased prevalence of early embryonic death; twinning is the commonest single cause of abortion. Spontaneous prolonged dioestrus is common in summer but may be effectively treated.Bacterial endometritis may result mainly from secondary pathogenic activity by organisms of the normal uterine flora; diagnosis by endometrial smear examination is accurate and methods of treatment have improved. The virus of horse pox has been identified, and the occurrence of equine infection with Mycoplasma has been confirmed.In the male, recent work has emphasized that reproductive function is seasonal. The presence or absence of an undescended testis can now be accurately determined.RÉSUMÉLes juments ovulent rarement en hiver; l'ovulation est induite par l'augmentation de la lumière du jour. Les oeufs s'accumulent dans les oviductes chez les juments non saillies.Durant la gestation les corps jaunes s'accumulent: ils régressent tous ensemble vers le milieu de la gestation.Le taux plasmastique de progesterone s'élève et le taux d'oestrogène s'abaisse à la fin de la gestation.Il existe des méthodes pour déterminer précocement la gestation et pour induire la mise bas.La gestation peut être diagnostiquée efficacement par palpation transrectable et par détermination immunologique du taux de PMSG. La saillie sur la chaleur de poulinage a pour conséquence un accroissement du nombre des résorptions embryonnaires précoces.La gemelliparité est la cause simple la plus fréquente des avortements. Un dioestrus spontané prolongé est fréquent en été mais peut être facilement traité.Il est possible que les endométrites bactériennes soient dues essentiellement à une activité secondaire pathogène de la flore utérine normale. Le diagnostic par frottis de l'endometre est efficace et les méthodes de traitement ont été améliorées.Le virus du Horse Pox a été identifié; l'existence de l'infection par des Mycoplasmes a été confirmée.Chez le mâle de récents travaux ont démontré que l'activité sexuelle est saisonnière. La présence ou l'absence d'un testicule inapparent peut être efficacement déterminée.Les juments ovulent rarement en hiver; l'ovulation est induite par l'augmentation de la lumière du jour. Les oeufs s'accumulent dans les oviductes chez les juments non saillies.Durant la gestation les corps jaunes s'accumulent: ils régressent tous ensemble vers le milieu de la gestation.Le taux plasmastique de progesterone s'élève et le taux d'oestrogène s'abaisse à la fin de la gestation.Il existe des méthodes pour déterminer précocement la gestation et pour induire la mise bas.La gestation peut être diagnostiquée efficacement par palpation transrectable et par détermination immunologique du taux de PMSG. La saillie sur la chaleur de poulinage a pour conséquence un accroissement du nombre des résorptions embryonnaires précoces.La gemelliparité est la cause simple la plus fréquente des avortements. Un dioestrus spontané prolongé est fréquent en été mais peut être facilement traité.Il est possible que les endométrites bactériennes soient dues essentiellement à une activité secondaire pathogène de la flore utérine normale. Le diagnostic par frottis de l'endometre est efficace et les méthodes de traitement ont été améliorées.Le virus du Horse Pox a été identifié; l'existence de l'infection par des Mycoplasmes a été confirmée.Chez le mâle de récents travaux ont démontré que l'activité sexuelle est saisonnière. La présence ou l'absence d'un testicule inapparent peut être efficacement déterminée.ZUSAMMENFASSUNGStuten ovulieren im Winter selten; die Ovulation wird induziert durch die Verlängerung der Tageslichtdauer. Bei nicht belegten Stuten akkumulieren sich Eier in den Eileitern. Während der Trächtigkeit sammeln sich auch Gelbkörper an, die sich dann alle miteinander etwa Mitte der Trächtigkeit zurückbilden. Die Plasma-Progesteronspiegel steigen gegen das Ende der Trächtigkeit an, während die Oestrogenspiegel abfallen. Es gibt verschiedene Methoden für einen vorzeitigen Abbruch der Trächtigkeit und die Einleitung der Geburt. Die Trächtigkeit wird diagnostiziert durch die rektale Untersuchung oder auch den immunologischen Nachweis von PMSG. Die Belegung in der Fohlenrosse wird von häufigerem embryonalem Frühtod gefolgt; Zwillingsträchtigkeiten gelten als häufigste Abortursache. Ein spontaner, verlängerter Dioestrus kommt im Sommer häufig vor, kann aber leicht behandelt werden.Bakterielle Endometritiden können hervorgehen aus einer sekundär-pathogenen Aktivität der normalen Uterusflora; die Diagnose aufgrund eines Endometrium-Abstriches ist zuverlässig; die Behandlungsmethoden sind verbessert worden. Das Virus der Pferdepocken konnte identifiziert werden und das Auftreten von Mycoplasma-infektionen bestätigt.Beim Hengsten wurde in neueren Untersuchungen ebenfalls eine jahreszeitliche Abhängigkeit der Fort-pflanzungsfunktionen beobachtet. Das Vorliegen oder das Fehlen nicht deszendierter Hoden kann jetzt genau bestimmt werden.Stuten ovulieren im Winter selten; die Ovulation wird induziert durch die Verlängerung der Tageslichtdauer. Bei nicht belegten Stuten akkumulieren sich Eier in den Eileitern. Während der Trächtigkeit sammeln sich auch Gelbkörper an, die sich dann alle miteinander etwa Mitte der Trächtigkeit zurückbilden. Die Plasma-Progesteronspiegel steigen gegen das Ende der Trächtigkeit an, während die Oestrogenspiegel abfallen. Es gibt verschiedene Methoden für einen vorzeitigen Abbruch der Trächtigkeit und die Einleitung der Geburt. Die Trächtigkeit wird diagnostiziert durch die rektale Untersuchung oder auch den immunologischen Nachweis von PMSG. Die Belegung in der Fohlenrosse wird von häufigerem embryonalem Frühtod gefolgt; Zwillingsträchtigkeiten gelten als häufigste Abortursache. Ein spontaner, verlängerter Dioestrus kommt im Sommer häufig vor, kann aber leicht behandelt werden.Bakterielle Endometritiden können hervorgehen aus einer sekundär-pathogenen Aktivität der normalen Uterusflora; die Diagnose aufgrund eines Endometrium-Abstriches ist zuverlässig; die Behandlungsmethoden sind verbessert worden. Das Virus der Pferdepocken konnte identifiziert werden und das Auftreten von Mycoplasma-infektionen bestätigt.Beim Hengsten wurde in neueren Untersuchungen ebenfalls eine jahreszeitliche Abhängigkeit der Fort-pflanzungsfunktionen beobachtet. Das Vorliegen oder das Fehlen nicht deszendierter Hoden kann jetzt genau bestimmt werden.
Veterinary Clinics of North America-equine Practice, Jan 1, 2006
Assisted reproductive techniques have been developed to obtain pregnancies from subfertile mares ... more Assisted reproductive techniques have been developed to obtain pregnancies from subfertile mares and stallions and to salvage gametes after death. In recent years, these procedures have been used for clinical cases with repeated success. Although new developments occur, the basis for the success and future development of assisted reproductive techniques is our ability to collect and handle the equine oocyte successfully. This article focuses on important clinical aspects of oocyte collection and evaluation and briefly discusses the clinical use of assisted reproductive procedures in the horse.
The goal of this review is to provide evidence supporting the physiologic basis for the use of ac... more The goal of this review is to provide evidence supporting the physiologic basis for the use of acupuncture as a treatment in equine reproduction, and to discuss current uses of acupuncture for the treatment of anestrus, urine pooling, uterine infection and/or fluid, infertility, maintenance of pregnancy, cryptorchidism, musculoskeletal pain, and poor libido in stallions. The benefits achieved through acupuncture treatment are thought to be a result of hormonal regulation, altered smooth muscle motility, and general stress and/or pain relief from musculoskeletal or environmental conditions.
The liberalization of European animal breeding legislation and an increasing diversity of equestr... more The liberalization of European animal breeding legislation and an increasing diversity of equestrian sports have led to a constant rise in the number of horse breeds and breed registries. In addition to the trend towards more and smaller breed registries, there is another trend towards an international expansion of the bigger established sport horse breeds. Regional breeds, at least in smaller countries, may no longer be able to run an independent breeding programme. The typical horse breeder, in the future, will be a female and qualified in equestrian sports. Artificial insemination (AI) mainly with fresh or cooled-transported semen has become a major breeding tool, allowing breeders all over Europe to benefit from the best stallions of most breeds. New AI techniques such as low-dose insemination may remain restricted to individual stallions and also the interest of breeding programmes in sex determination of foals via semen sorting is limited. Embryo transfer and associated techniques, although allowed by most breeds, have not contributed significantly to genetic progress in European sport horses so far. A potential use of cloning may be to produce gonad-intact copies from geldings that have performed to a superior level. With a more open and international structure of horse breeding and increased use of AI, equine reproduction and biotechnology should be emphasized by veterinary curricula and continuing professional education programmes.
Doppler ultrasound is an emerging technology that has the potential to increase the diagnostic, m... more Doppler ultrasound is an emerging technology that has the potential to increase the diagnostic, monitoring, and predictive capabilities of equine theriogenologists and researchers. The technology is based on Doppler-shift frequencies, wherein the ultrasound frequency of echoes from moving red cells is increased or decreased as the cells move toward or away from the transducer. In spectral mode, the blood flow in a specific vessel can be assessed by placing a sample-gate cursor on the image of the lumen of the vessel. In addition, an angle cursor can be used to represent the angle of intersection of the ultrasound beams with the direction of blood flow (Doppler angle). The Doppler-shift frequency and the Doppler angle are used by the instrument for computing blood velocity. The focused results from placement of a sample gate in an artery are displayed by a spectrum that represents the changing velocities over time in association with the pulses of cardiac cycles. Peak systolic, end diastolic, and time-averaged maximum velocities are computed and shown for a selected cardiac cycle. Doppler indices (resistance index, RI; pulsatility index, PI) are ratios that are computed from various points on the spectrum. The indices are relatable to the hemodynamics of the tissue supplied by the artery. Increasing RI or PI values indicate increasing resistance and decreasing perfusion of the distal tissues. In color-flow mode, Doppler-shift frequencies are obtained from areas delineated by the operator on the B-mode image and are transformed and expressed as color-coded spots representing areas of blood flow. Vascular perfusion of a structure can be quantitated by the number of colored pixels in an image or can be estimated subjectively by the extent of the colored spots. The Doppler technology has the potential for providing information on the status and future success of a structure. However, realization of the expected potential will depend on future experience and research.
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