Topic:Broodmares
Broodmares are adult female horses that are used for breeding purposes. They play a vital role in equine reproduction, contributing to the continuation of specific bloodlines and the development of desirable traits in offspring. The management of broodmares involves various aspects, including nutrition, health monitoring, and reproductive care, to ensure successful conception, gestation, and foaling. Horses, as a broader category, include both males and females and encompass a wide range of breeds and disciplines. The study of broodmares and horses encompasses reproductive physiology, genetic considerations, and husbandry practices. This page compiles peer-reviewed research studies and scholarly articles that explore the management, reproductive health, and genetic aspects of broodmares, as well as general equine care and breeding strategies.
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...
Day of cycle affects changes in equine intrauterine pressure in response to teasing. Oxytocin is released in response to teasing during both estrus and diestrus in mares, and at least during estrus, teasing results in an increase in electromyographic activity in the uterus. Exogenous oxytocin causes an increase in intrauterine pressure and prior studies have shown that this response is correlated to the day of the estrous cycle. To determine if teasing causes an increase in intrauterine pressure and if this response varies by day of the cycle, intrauterine pressure was measured while mares were teased with a stallion 2 days before ovulation, on the day ovulation was detected a...
Serum thyroxine concentrations and pregnancy rates 15 to 16 days after ovulation in broodmares. To determine whether serum thyroxine (T4) concentration was associated with pregnancy rates 15 to 16 days after ovulation in mares and to determine whether thyroid hormone supplementation would enhance fertility in mares. Methods: Cohort study. Methods: 329 clinically normal broodmares. Methods: Mares were examined 15 to 16 days after ovulation to determine whether they were pregnant; blood samples for determination of serum T4 concentration were collected at the same time. Sixty mares were receiving thyroid hormone supplementation prior to the study because of low serum T4 concentration (< 16...
Evaluation of the field application of PCR in the eradication of contagious equine metritis from Japan. The effectiveness of the polymerase chain reaction (PCR) as a field application test for the eradication of contagious equine metritis (CEM) was evaluated. Seven-thousands five-hundred and thirty-four genital swabs were collected from 4,026 Thoroughbred broodmares and stallions in Japan to test "high risk" horses as well as for general surveillance testing from 1998 to 2001. Bacterial isolation as well as PCR testing of original specimens and cultured specimens was performed for detection of Taylorella equigenitalis from genital swabs. As a result, T. equigenitalis was detected in 12 mares and...
Matua bromegrass hay for mares in gestation and lactation. Matua bromegrass hay (Bromus willdenowii Kunth) is a high quality forage, but its value for mares during gestation and lactation is not well known. Intake, rate of passage, performance, and reproduction by gestating and lactating Quarter Horse mares fed the hay was investigated. In this experiment, 12, 2- to 12-yr-old gravid mares (mean BW = 553 kg, SD = 36) were fed Matua hay (CP = 11.5%) or alfalfa hay (Medicago sativa L.) (CP = 15.4%) for variable days prepartum (mean 59.9 d; SD = 23.5) and for 70 d postpartum. Matua and alfalfa hay were fed as the roughage portion of the diet with a grain ...
Factors affecting gestation length in the Thoroughbred mare. In order to assist in the accurate prediction of the timing of parturition in the mare true gestation length, along with the potential effect of a number of factors, was investigated. Data from 433 Thoroughbred foal pregnancies were used. Sequential ultrasonic scanning allowed the true gestation length (fertilisation-parturition) to be ascertained, as apposed to previous work, which used the mating-parturition interval. An average gestation length of 344.1 +/- 0.49 days was evident. Colt foal pregnancies were significantly (P < 0.001) longer (346.2 +/- 0.72) than fillies (342.4 +/- 0.65). Mont...
Major constituents, leptin, and non-protein nitrogen compounds in mares’ colostrum and milk. Five Haflinger mares were hand-milked at 0 h (pre-suckle) and 6 h (postsuckle), 12, 24, 48, 72 and 96 h after parturition. Total solids, protein, fat, lactose, calculated gross energy content, leptin and non-protein nitrogen components (urea, alpha-amino nitrogen, creatinine and allantoin) were determined. The levels of the major constituents differed significantly in pre-suckle colostrum from subsequent samples. Leptin levels were the highest in whole (9 ng x mL(-1) of immunoreactive human equivalent HE +/- 0.48 ng x mL(-1), SEM) and skimmed (7.8 ng HE x mL(-1) +/- 0.52 ng x mL(-1), SEM) pre-...
Reproductive performance of Friesian mares after retained placenta and manual removal of the placenta. Because the incidence of retained placenta in Friesian mares is estimated to be high, and no reports have been published on the reproductive performance of Friesian mares after retained placenta, we studied postpartum reproductive performance in Friesian brood mares with (n = 54) and without (n = 50) retained placenta. We defined a retained placenta as the failure to expel all fetal membranes within 3 h after the delivery of a foal. We subdivided the group of mares with retained placenta into mares in which the placenta had been removed manually (n = 30) and mares in which it had not (n = 24)....
Population-based study of fecal shedding of Clostridium perfringens in broodmares and foals. To determine the percentage of broodmares and foals that shed Clostridium perfringens in their feces and classify the genotypes of those isolates. Methods: Prospective cross-sectional study. Methods: 128 broodmares and their foals on 6 equine premises. Methods: Anaerobic and aerobic bacteriologic cultures were performed on feces collected 3 times from broodmares and foals. All isolates of C. perfringens were genotyped. Results: Clostridium perfringens was isolated from the feces of 90% of 3-day-old foals and 64% of foals at 8 to 12 hours of age. A lower percentage of broodmares and 1- to 2-mon...
Reproductive efficiency of intensively managed Thoroughbred mares in Newmarket. The findings of a retrospective survey of 1393 Thoroughbred mares visiting 22 studfarms in the Newmarket region of the UK during the 1998 mating season were compared with those of a similar study undertaken in 1983. The effects of mare age and status, stallion, month of mating, application of uterine treatments and other parameters on the rates of singleton and twin conception and subsequent pregnancy losses were analysed. Mare age and status significantly affected the per cycle pregnancy rate and the incidence of pregnancy loss. Overall, the mean number of matings per oestrus was 1.12 and the...
Content of meiosis activating sterols in equine follicular fluids: correlation to follicular size and dominance. Meiosis activating sterols (MAS) are pre-cholesterol sterols that can be isolated from follicular fluid (FF-MAS) or testes (T-MAS). Meiosis activating sterols trigger the resumption of meiosis in cultured meiotically competent oocytes. In the present work MAS, cholesterol and progesterone were assayed by HPLC in follicular fluids collected from pony mares at fixed days after the last ovulation. Follicles were divided into two groups according to whether they were aspirated before or after Day 17 after the last ovulation. The latter group was further divided according to whether the follicle di...
Use of oocyte transfer in a commercial breeding program for mares with reproductive abnormalities. In some mares with lesions of the reproductive tract, embryo collection and survival rates are low, or collection of embryos is not feasible. For these mares, oocyte transfer has been proposed as a method to induce pregnancies. In this report, a method for oocyte transfer in mares and results of oocyte transfer performed over 2 breeding seasons, using mares with long histories of subfertility and various reproductive lesions, are described. Human chorionic gonadotropin or an implant containing a gonadotropin-releasing hormone analog was used to initiate follicular and oocyte maturation. Oocyte...
[The “problem” mare part 3: veterinary supervision at the stud and during early pregnancy]. In this last article the veterinary supervision of problem mares at the stud is reviewed. Treatment possibilities are evaluated. The usefulness of treatment with progestagens in order to sustain pregnancy or to prevent embryonic death is discussed.
Evidence for a seasonal variation in the ability of exogenous melatonin to suppress prolactin secretion in the mare. In seasonally breeding species photoperiodic information is thought to be conveyed to the reproductive and prolactin axis via changes in circulating concentrations of melatonin. For some species, a constant melatonin stimulus is perceived as a short day, whereas in others no photoperiodic information is provided. In the mare, a preliminary study demonstrated that constant administration of melatonin did not modify prolactin secretion, suggesting that this treatment regimen failed to provide photoperiodic information. To further investigate this proposal and to investigate an alternative explan...
Oxytocin release and its relationship to dihydro-15-keto PGF2alpha and arginine vasopressin release during parturition and to suckling in postpartum mares. Pituitary blood was collected from the intercavernal sinus in five mares before and during parturition, and in nine mares immediately after parturition to investigate oxytocin patterns during parturition and early lactation, and to determine the relationship between oxytocin, prostaglandin and arginine vasopressin during parturition. In four mares in which sample collection began at least 6 h before rupture of the chorioallantois, a significant increase (P < 0.05) in PGF(2alpha) concentration was detected before a significant increase in oxytocin concentration. Cross-correlation analysis of...
Foaling-management practices associated with the occurrence of enterocolitis attributed to Clostridium perfringens infection in the equine neonate. Enterocolitis associated with Clostridium perfringens (C. perfringens) infection in neonatal foals is often severe and has been associated with a high case-mortality risk. We designed a premises-based survey to evaluate the associations of regional foaling practices, premises environmental management, periparturient foal and brood-mare management, and periparturient brood-mare ration with the occurrence of neonatal enterocolitis attributed to C. perfringens infection. Potential risk factors individually associated with enterocolitis were breed type, housing type at foaling and in the first thr...
[Health aspects and the duty of care in the rearing of young horses]. Future competition horses may suffer from health impairments due to complex or partial genetic components as well as to management faults in respects to keeping, feeding and health prophylaxis against infectious diseases. This health risks exist during the whole rearing period: from late pregnancy till far beyond weaning. Health impairments reduce trade value and practical use, and interfere with aspects of animal protection. In the field of breeding permission, first in stallions, applied research ist needed. For horse farms a praxis-oriented comprehensive advisory service should be establish...
Relationship between ultrasonic characteristics of the corpus luteum, plasma progesterone concentration and early pregnancy diagnosis in Friesian mares. The purpose of the present study was to evaluate the change in cross-sectional area of the early corpus luteum (CL) and progesterone production in relation to subsequent pregnancy diagnosis. The cross-sectional area of the CL of 75 Friesian brood mares was measured by ultrasonography on Day 1 or 2 and Day 8 or 9 after ovulation. The change in cross-sectional area was expressed in a volume ratio. Plasma progesterone concentrations were measured on Days 8 to 9, and ultrasonography to determine pregnancy status was carried out on Day 17. The data obtained were analyzed by using a multiple logisti...
Fertility comparison between breeding at 24 hours or at 24 and 48 hours after collection with cooled equine semen. It has become a common practice in the equine breeding industry to send 2 insemination doses for breeding with transported cooled semen, one to be used for the initial insemination upon arrival, and the other to be held a second insemination the next day. One fertile stallion and 36 fertile mares were used to determine if breeding once with 1 dose of semen cooled for 24 h would improve fertility compared with breeding twice, 1 d apart, with half the dose of semen cooled for 24 h on the first day of breeding and half cooled for 48 h on the second day of breeding. Mares were given two intramuscu...
Effects of melatonin implants in pony mares. 2. Long-term effects. The effects of melatonin implant treatment over a 4 wk period at the summer solstice on the transition into and out of the following anovulatory season were evaluated in ovary-intact and ovariectomized mares. Melatonin implants tended to delay the timing of the final ovulation of the breeding season (P = 0.0797) in the ovary-intact mares. Although the decline in LH secretion associated with the end of the breeding season was parallel between treatments and ovarian statuses, the rate of LH secretion, as expressed by its mathematical accumulation, was lower in ovariectomized, melatonin-treated m...
Administration of oxytocin immediately after insemination does not improve pregnancy rates in mares bred by fertile or subfertile stallions. It is probable that reduced pregnancy rates in mares bred to subfertile stallions is attributable, in part, to the reduced number of normal spermatozoa that colonize the oviduct. Administration of oxytocin stimulates both uterine and oviductal contractility. The hypothesis that oxytocin may enhance sperm transport to/into the oviducts, and thereby increase pregnancy rates, was tested in 2 trials. For both trials, fertile estrous mares with follicles > or = 35 mm in diameter were inseminated once at 24 h after administration of 1500 to 2000 U hCG. The inseminate dose was limited to 100 milli...
Arthrodesis of the proximal interphalangeal joint affected with septic arthritis in 8 horses. Arthrodesis was performed to treat septic arthritis of the proximal interphalangeal joint of 8 horses. Records of the horses were reviewed to determine outcome and possible factors that influenced success or failure. All horses were female. Seven horses had 1 joint treated and 1 horse was treated for bilateral pelvic limb involvement. The duration of sepsis before surgery ranged from 1 to 66 days. Bone lysis and production was radiographically apparent in 7 horses before surgery. Six horses had multiple bacterial organisms cultured from bone or synovial tissues; 2 horses had single isolates id...