Anti Müllerian Hormone, AMH, is believed to be the main agent in the freemartin syndrome. Supposing an active role of freemartin gonads in AMH secretion, in the present study, we aimed at investigating the presence and the localization of AMH producing cells either in fetal or in adult freemartin gonads. Our finding of positive AMH cells in a 26-week-old freemartin fetus indicates an active role of masculinized freemartin gonads in AMH secretion. However, the positive reaction, limited to few cells grouped in 'nests' in proximity to testis cord-like structures, supports a chimeric origin of such cells, migrated from the male co-twin. No adult freemartin, irrespective from the degree of masculinization, showed any AMH positive cell.

A 9 year old mare presented to be visited with haemorragic vaginal discharge, that had been going on for about 1 week. After an accurate clinical exam, the origin of the discharge was discovered: an ulceration of some large veinous vessels, found on a residual of hymen. The ulceration and thrombosis of large varicous veins could be one of the various causes responsible for such discharge. However, the localization on the residual of the hymen is an unusual and rarely reported site for such phenomenon to occur, while more commonly it is the dorsal portion of the vagina to be involved.We hence discuss the differential diagnosis of such symptoms, and possible aetiologies and predisposing factors that lead to such vascular abnormality, as well as discussing possible treatments.

The release of PGF(2 alpha) was monitored during specific phases of the reproductive cycle of artificially inseminated mares. Daily progesterone concentration was measured to detect a possible corpus luteus failure. Five fertile and regularly cycling mares were inseminated with fresh semen from a fertile stallion. the PGF(2 alpha) main metabolite (PGFM) concentration was measured during time windows of 90 minutes at oestrous, 12 hours after the last A.I., and on days 5, 4, 7, 12 following ovulation. three mares were diagnosed pregnant after the first A.I. session and one mare after the second. The analysis of PGFM concentration (both mean values and area under the curve) did not reveal any significant difference among mares or between pregnant and non-pregnant animals. Progesterone concentration was not correlated to PGFM pattern. There was a high variability among animals, both in basal PGFM values (i.e. before A.I.) and in the subsequent determinations. We found no evidence that barren mares have PGFM concentrations different from pregnant ones in critical phases of the oestrous cycle.

The aim of this study was to compare the effect of ethylene glycol versus glycerol for dog semen freezing, on post-thaw longevity, motility and motility parameters, and on plasma membrane functional integrity.Semen was diluted in two steps with an egg yolk TRIS extender containing a final concentration of either 5% glycerol or 5% ethylene glycol, and frozen in 0.5 ml straws, with 100 X 10(6) spermatozoa/ml, over nitrogen vapours.Semen motility was evaluated both under a light microscope and with a Computer Assisted Motility Analyser System, immediately after thawing and then hourly till 4 h of incubation. Sperm membrane functional integrity was assessed with the hypoosmotic swelling test (60 mOsm fructose solution) applied at thawing and then hourly, for 4 h, on incubated samples.Motility (light microscope) and total and progressive motility (analyser) were significantly higher in ethylene glycol frozen samples at thawing (P < 0.01); from hour 1 onwards the effect of the cryoprotectant became not significant. Semen frozen with ethylene glycol showed higher path velocity and higher straight line velocity till 3 h after thawing; however, ethylene glycol semen samples also showed higher curvilinear velocity and higher lateral head displacement, which may indicate a capacitation-like condition affecting sperm membranes and possibly reducing post-thaw longevity. Functional integrity of plasma membrane was similar in glycerol and ethylene glycol samples till 3 h after thawing, then ethylene glycol samples showed a higher decline. The strong though short-lived positive effect of ethylene glycol is worth being evaluated further. (c) 2005 Elsevier Inc. All rights reserved.

The meiotic competence of canine oocytes collected from anoestrous bitch ovaries and cultured for 72 h in different media was studied. The base culture medium was TCM 199 enriched with 10% fetal bovine serum (TCM); the effect of supplementation with EGF (50 ng x mL(-1)) or ITS (insulin: 10 microg x mL(-1); transferrin: 5.5 microg x mL(-1); selenium: 5 microg x mL(-1)) was also studied. TCM was also compared to a Synthetic Oviductal Fluid (SOF). All the media contained FSH (0.1 UI x mL(-1)), LH (10 UI x mL(-1)), 17beta-oestradiol (4 microg x mL(-1)) and kanamycin. Despite the anoestrous stage of the donor bitches, resumption of meiosis occurred in a high proportion of the oocytes, (mean value 77.3%). The number of oocytes showing the 'germinal vesicle breakdown' nuclear stage was not influenced by the type of the culture medium used. ITS had a positive effect on nuclear progression to later stages (from metaphase I to metaphase II); however, this effect was not statistically significant.

Current techniques for in vitro horse reproduction are still in a preliminary phase and far from being of practical field applicability. The aim of this work is to give an overview of the "state of the art" equine oocytes collection methods, maturation media and fertilization techniques are described and their relative results and success rates are compared. From this literature review we gather Interesting hints for further studies on many aspects of horse oocytes maturation, fertilization and embryo development which are still unclear.