REASONS FOR PERFORMING STUDY Active immunisation against gonadotrophin-releasing hormone (GnRH) provides a reversible method for control of oestrous behaviour and fertility in mares. Previous reports failed to demonstrate the interval to resumption of cyclic ovarian activity after GnRH-vaccination. HYPOTHESIS Administration of the GnRH-vaccine Improvac in a large group of mares of various age...

Equine coital exanthema (ECE), caused by equid herpesvirus 3 (EHV-3), has been recognized as an economically significant venereal disease for years. However, no infection models on the natural host have been established. In order to set up an experimental infection protocol, seronegative and seropositive mares were topically inoculated in the perineal region with 4 × 10(6)TCID(50)/ml of EHV-3. ...

Follicular diameter is used as a guiding tool to predict ovulation in the mare. However, the great range in preovulatory follicular diameter makes prediction of optimal breeding time based on follicular diameter unreliable. Uterine edema pattern is also useful to determine the best time to breed, since intensity of edema tends to dissipate as ovulation approaches, however, not every mare follow...

Microelements concentrations of Al, Co, Cr, Li, Mo, Ni, Sb and Sr were determined in the milk of Croatian Coldblood mares by inductively coupled plasma-optical emission spectrometry. The total mean element contents in mares milk were (mg/kg): Al<10, Co<10, Cr 26.7, Li 4.35, Mo 11.0, Ni<10, Sb 70.1 and Sr 467. Variation of Li, Sb and Sr concentrations were found throughout the lactation stages (...

Uterine lavage is commonly used in the peri-ovulatory period to improve pregnancy rates in mares with reduced fertility. Previous work has shown that uterine lavage with lactated Ringer’s solution performed immediately before insemination does not affect the fertility in reproductively healthy mares. In the present field study, uterine lavage using lactated Ringer’s solution was performed on a ...

Regulative endocrine mechanisms influence the reproductive behaviour and success of mammals, but they have been studied predominantly in domestic and captive animals. The study aims at describing the pattern of faecal 20-oxopregnane and oestrogen concentrations during pregnancy in wild plains zebra Equus quagga chapmani. Data were collected during wet and dry seasons 2007-2009. Enzyme Immunoass...

The physiologic breeding season of horses extends from April to October in the Northern Hemisphere. Mares are polyestrous in that they exhibit repeated estrous cycles during the breeding season. In the winter months, 80% or more of mares enter a prolonged anovulatory phase referred to as winter anestrus. The onset of the transition period may be defined as the first significant increase in foll...

Fertility problems of mares on a well-managed breeding farm with thoroughbred stallions have been ascribed mostly to contamination of the reproductive apparatus of females with pathogens, particularly those of bacterial origin. This study presents a summary of the frequency of bacterial pathogens isolated from 437 cervical swabs which were collected from English thoroughbred mares intended for ...

To investigate the maternal plane of nutrition and role of Se yeast on foaling variables and passive transfer of IgG, 28 Quarter Horse mares were used in a study with a randomized complete block design. Mares were blocked by expected foaling date and assigned randomly within block to dietary treatments. Dietary treatments were arranged as a 2 x 2 factorial with 2 planes of nutrition, pasture or...