Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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.
Limitations in equine fetal electrocardiography. Technical and interpretive limitations of equine fetal electrocardiography were evaluated in recordings obtained from 45 pregnant mares. Technical limitations were related to the small amplitude of the fetal electrocardiogram and the variability in the lead configuration providing the best recording. It was found that recording the fetal electrocardiogram at high sensitivity and high base-line fidelity in several different leads was necessary to obtain satisfactory tracings. Interpretive limitations were related in part to the small amplitude of the fetal electrocardiogram and to the marked va...
[The effect of the age of stallions and mares on their fertility]. The study was based on the documentation of the Napajedla Stud Farm of the English Thoroughbred horse for 1888-1972. Evaluating the effect of the age of stallions on their fertility (leaving aside the variability of the age of their mothers), such an effect was found to be significant only in four out of the 26 studs evaluated. In 65% of the selected stallions, the correlation coefficients were found to be negative, but without statistical significance. However, the objective of the study was to evaluate stallions and mares parallelly as to their age variability and fertility. The relationship...
Vaccination of pregnant ponies against equine rhinopneumonitis. Bovine herpesvirus 1247 (one dose) was given subcutaneously to five pregnant pony mares between 227 and 319 days of their gestations. There were no adverse clinical reactions, and the virus was not recovered from nasal swabs collected during a 2-week period after vaccination. Four ponies foaled full-term, live, healthy foals. The foal of the fifth mare (No. 1) was found dead, but on the basis of the pathologic and virologic examinations, the virus was not considered to be the cause of the death. At 3 weeks after vaccination, the pregnant pony mares had a 13- to 250-fold increase in serum antib...
Preliminary studies on the use of an oral progestogen to induce oestrus and ovulation in seasonally anoestrous Thoroughbred mares. Daily oral administration of 30 mg allyl trenbolone (Regumate) for 10 to 15 days to 61 barren, maiden and lactating Thoroughbred mares which were exhibiting either deep anoestrus, shallow anoestrus, prolonged spring oestrus or lactation anoestrus, resulted in 54 mares (88 per cent) showing oestrous behaviour within 8 days, and 51 mares (84 per cent) ovulating within 18 days, after the last dose of compound. Response rate was lowest in mares in deep anoestrus. Of the 38 Regumate-treated mares which were covered during the induced oestrus, 21 (55 per cent) conceived. The practical value of this ...
Combined immunodeficiency of Arabian horses: confirmation of autosomal recessive mode of inheritance. A 3-year prospective breeding trial was designed to verify the mode of inheritance of combined immunodeficiency (CID) in Arabian horses. Twenty-six mares that had previously produced foals with CID were mated to a stallion that had sired foals with CID. Of 53 foals obtained, 15 (28.3%) had CID. The ratio of female to male foals was 28:25, and the ratio of female CID to male CID foals was 8:7. The results of this trial confirmed a suggestion that CID in Arabian horses is inherited as an autosomal recessive trait.
Purification and characterization of donkey chorionic gonadotrophin. Serum of the pregnant donkey, like that of the mare, contains a gonadotrophin of chorionic origin. The chorionic gonaditrophin of the donkey (dCG) has been isolated in purified form from the serum of pregnant donkeys using methodology previously employed for the purification of pregnant mare chorionic gonadotrophin (eCG). Unlike eCG, dCG is predominatly an LH in biological tests. In the in-vitro rat Leydig cell assay, dCG was as active as eCG, but in the in-vitro rat seminiferous tubule assay for FSH and in the augmentation assay, dCG was considerably less potent than eCG (1-10%). Specific rat...
[The effect of inbreeding on the manifestations of some physiological traits in the Kladrub Black Horse strain]. Inbreeding was used in the regeneration process in the breeding of the Kladrub Black Horse. Inbreeding rate is realized in practice, as related to the manifestation of the selected characteristics of this unique horse population. The evaluation of the effect of inbreeding on conception rate and fertility did not demonstrate any differences between the group of inbred mares and non-inbred mares. The study was conducted in mares used for breeding for 10 years. The results provide evidence that inbreeding causes no depression in this characteristics in the Kladrub Black Horse which would otherwis...
Concentrations of circulating gonadotropins during various reproductive states in mares. Concentrations of circulating FSH and LH were measured in pony and horse mares during the estrous cycle. The gonadotropin profiles did not differ significantly between the two types of mares. During the estrous cycle FSH and LH were secreted in a reciprocal pattern with FSH high during diestrus and LH high during estrus. Although the patterns of FSH and progesterone secretion were similar, FSH rose before progesterone at the end of estrus, indicating that the initial FSH increase was not due to a positive feedback effect of progesterone. The patterns of LH, but not of FSH secretion, diverged b...
[Estimation of the heritability coefficient of stud fertility]. The breeding documentation of the English Thoroughbred horse breeding farm at Napajedla was analyzed to study some effects acting upon the fertility of studs and mares and the length of gravidity. The heritability of fertility is the subject of this report. The normality of the distribution of fertility was tested by processing 300 data on fertility at the given significance level sup / Fn(xi) - F(xi) / less than or equal to Dn(a). The value of the supreme D(300) = 0.108 is lower than the critical level for alpha 0.05. The estimation of fertility heritability coefficient indicates that h2 = 0....
Low doses of oxytocin can induce foaling at term. Levels of the major circulating metabolite of prostaglandin F-2 alpha, 13, 14 dihydro-15-oxo-prostaglandin F-2 alpha (PGFM) were measured during the induction of foaling using small (2.5-10 iu) intravenous doses of oxytocin. PGFM levels rose rapidly in all animals within 15 min of injection and were associated with typical signs of second stage labour. Because these small doses of oxytocin are effective in successfully triggering parturition it is suggested that higher doses (40-120 iu) used to induce birth in other studies are unnecessary and could be potentially dangerous to the foetal foal....
Obstetrician’s view of the physiology of equine parturition and dystocia. The author reviews 40 years of clinical experience including more than 1000 cases of dystocia in mares of different breeds. The high incidence of stillbirth and perinatal mortality of the foal, severe lesions of the genital tract developing during foaling and in the early post partum period are discussed and suggestions made for their prevention and treatment. The advantages of partial embryotomy to avoid unnecessary caesarean sections are emphasised. Special attention is given to the causes of and approach to cases of prolonged gestation; to dystocia caused by retroversion of preparturient to...
The immunological approach to pregnancy diagnosis: a review. The developing embryo/fetus bears antigens which are foreign to the mother and it could be expected that immune rejection of the conceptus would occur. One of the reasons why the fetus is not rejected is because a depression of the maternal immune response takes place during pregnancy. Serum from pregnant animals of several species has been shown to contain a factor, early pregnancy factor (EPF), which is immunosuppressive. EPF has been detected as early as six hours after mating and its detection could aid diagnosis of early pregnancy in all species.
