Regression of the corpus luteum (CL) is characterized by a decay in progesterone (P4) production (functional luteolysis) and disappearance of luteal tissues (structural luteolysis). In mares, structural luteolysis is thought to be caused by apoptosis of luteal cells, but functional luteolysis is poorly understood. 20α-hydroxysteroid dehydrogenase (20α-HSD) catabolizes P4 into its biologically i...

The effects of cooling, storage, glycerolization and spermatozoal numbers on fertility were investigated utilizing three stallions and 72 mares. Semen was extended in a cream-gel extender and inseminated: a) within 1 hr (fresh) at 38 C, b) after cooling for 2 hr to 5 C, c) after cooling for 2 hr plus the addition of 7% (v/v) glycerol, and d) after cooling for 24 hours. Onehalf of the mares were...

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 ...

BACKGROUND Intrauterine infusions have been widely used for the treatment of endometritis in the mare. Nevertheless, their consequences on endocrine and endometrial molecular aspects are unknown. We studied the effect of a 1% povidone-iodine solution intrauterine infusion on progesterone levels, endometrial histology and estrogen (ERα) and progesterone (PR) receptor distribution by immunohistoc...

A study of the duration oestrus and estrous cycles in mares from Haflinger breed (HB) influence some factors was conducted. The records used for this were breeding registers State Stud farm Kabiuk near Shumen, covering a period 11 years (2009 to 2020). In included 15 with 110 estruses 22 cycles. With breed, average is 5.52 ± 0.26 days length cycle 24.21 1.13 days. year (P<0.001), month season (...

Four experiments were conducted 1) to assess the use of glucose responses to insulin injections as a means of estimating insulin sensitivity in horses and 2) to compare the insulin sensitivities of normal horses vs. those displaying hyperleptinemia (HL). In Exp. 1, HL mares and geldings (n = 4 each) and 4 mares and geldings with normal leptin concentrations (NL) were injected intravenously with...

This study investigated the effects of different artificial insemination (AI) regimes on the pregnancy rate in mares inseminated with either cooled or frozen-thawed semen. In essence, the influence of three different factors on fertility was examined; namely the number of inseminations per oestrus, the time interval between inseminations within an oestrus, and the proximity of insemination to o...

Stereotypies are invariant and repetitive behaviour patterns that seemingly have no function, which tend to develop in captive animals faced with insoluble problems and may be indicative of reduced welfare. A 4 year prospective study of the factors influencing the development of stereotypic and redirected behaviours (abnormal behaviour) in a population of 225 young Thoroughbred and part-Thoroug...

REASONS FOR PERFORMING STUDY Artificial lighting is commonly used to advance the breeding season in horses. Light masks have been developed that direct light at a single eye to inhibit the production of melatonin, the decoder of photoperiod for seasonally breeding animals. OBJECTIVES To investigate whether low-intensity blue light from light masks was effective at advancing the breeding seaso...