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Topic:Reproduction
Reproduction in horses encompasses the biological processes and mechanisms involved in the breeding and development of equine offspring. This includes the study of reproductive anatomy, physiology, and endocrinology in both mares and stallions. Key areas of interest include the estrous cycle, ovulation, conception, gestation, and parturition. Researchers also examine factors influencing fertility, reproductive technologies such as artificial insemination and embryo transfer, and management practices that impact reproductive success. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological, genetic, and environmental aspects of equine reproduction.
Formation of steroids by the pregnant mare. VI. Metabolism of [14C]farnesyl pyrophosphate and [3H]dehydroepiandrosterone injected into the fetus. A mixture of [4,8,12-14C]farnesyl pyrophosphate and [3H]dehydroepiandrosterone was injected into a horse fetus im during laparotomy, after which maternal urine was collected for 6 days. Steroid conjugates in the urine were extracted with Amberlite XAD-2 resin, hydrolyzed, and separated into phenolic and neutral fractions. Estrone, 17 alpha-estradiol, equilin [3-hydroxy-1,3,5(10),7-estratetraen-17-one], and 17 alpha-dihydroequilin [1,3,4(10),7-estratetraene-3,17 alpha-diol] were isolated from the phenolic fraction and their radiochemical purities were established. Only estrone and 17 alpha-estr...
The measurement of oestrone, equilin and dehydroepiandrosterone in the peripheral plasma of pregnant pony mares by radioimmunoassay. Oestrone, equilin and dehydroepiandrosterone were measured by radioimmunoassay in peripheral plasma from five pony mares; samples were taken from day 60 of pregnancy at approximately weekly intervals through to parturition. Of the three steroids measured, dehydroepiandrosterone showed the most consistent pattern of secretion. DHA concentrations remained low until day 105, increased rapidly from day 120 and attained maximum values between days 168–210; levels declined to day 300, but there was considerable variation between mares in DHA patterns prior to parturition. There was great variation...
Contagious equine metritis: the present situation reviewed and a revised code of practice for its control. This report contains details of the code of practice for the control of contagious equine metritis (CEM) during the 1979 breeding season. It was prepared under the guidance of a scientific committee established by the Horserace Betting Levy Board under the chairmanship of Sir David Evans, FRS. The code is similar to the one introduced for the 1978 breeding season but takes into account the experience gained during the past 12 months. Following discussions with colleagues in Ireland it has been agreed that a similar code of practice will be introduced in the United Kingdom and Ireland so as to ...
Uterine luminal prostaglandin F in cycling mares. Prostaglandin F was measured by radioimmunoassay in uterine flushings of cycling mares on days 4, 8, 12, 14, 16, 18 and 20 post-ovulation. Prostaglandin F was significantly (P less than .05) affected by day of the estrous cycle and reached maximal levels on day 14. Least squares means for days 4, 8, 12, 14, 16, 18 and 20 were: .66, .81, 4.77, 14.31, 5.48, 3.68 and 2.97 ng/ml, respectively.
Contagious equine metritis: clinical description of experimentally induced infection. Contagious equine metritis was reproduced experimentally in 6 pony mares. The disease was characterized by rapidly developing cervicitis and by varying amounts of exudate. The exudate, apparent as early as 48 hours after inoculation, drained from the cervix as a tenacious, mucopurulent discharge for several days, then rapidly disappeared. In all mares, the clinical disease cleared within several weeks of inoculation, without treatment.
Foetal and maternal plasma concentrations of 13, 14-dihydro-15-oxo-prostaglandin F in the mare during late pregnancy and at parturition. The concentrations of 13, 14-dihydro-15-oxo-prostaglandin F(PGFM), the stable metabolite of prostaglandin F, were measured in the plasma of catheterized mares and foetuses and non-catheterized thoroughbred mares and ponies during the last months of gestation. The plasma concentration of PGFM increased gradually towards term in all groups of animals. During the operation for insertion of catheters, maternal and foetal concentrations of PGFM were high, but the values fell to basal levels 24--48 h after the operation. It was found the preoperative starvation (24 h) led to a rise in the concentrat...
Effects of endometrial biopsy, uterine culture, and cervical dilatation on the equine estrous cycle. In 10 mares, lysis of the corpus luteum was induced by endometrial biopsy and culture on day 4 after estrus, as evidenced by a sharp decline in serum progesterone concentration and a shortened interestrous interval. Estrus following the manipulations was prolonged. Endometrial biopsy and culture on days 1 and 3 after estrus or manually dilating the cervix on day 4 after estrus also decreased the serum progesterone concentration (within 24--48 hr after manipulation), shortened diestrus, and prolonged the subsequent estrus. In a 2nd experiment, endometrial biopsy on day 4 after estrus shortened ...
Plasma concentrations of sodium benzylpenicillin after intrauterine infusion in pony mares. Plasma concentrations of sodium benzylpenicillin were measured following intrauterine infusion at a dose rate of 22,000 u/kg (250,000 u/ml). The reproductive status of the mare at the time of infusion did not appear to influence plasma concentrations of penicillin, but preswabbing the endometrium for bacteriological culture resulted in peak plasma concentrations which were nearly twice those found in unswabbed mares.
Infection patterns in pony mares challenged with the agent of contagious equine metritis 1977. Contagious equine metritis 1977 was reproduced in pony mares using cultures of the Gram-negative coccobacillus aetiologically associated with the disease. Variability in clinical response was observed in the first of 2 experiments, with the presence of semen, either alone or in an extender, appearing to potentiate the pathogenicity of the challenge strain of the organism. The experimental disease was characterised by a variable degree of vaginal discharge and concomitant inflammatory changes involving the vervix and vagina. Although all of the affected mares recovered spontaneously, a high per...
