Characteristics of the equine embryo and fetus from days 15 to 107 of pregnancy

In spite of numerous, substantial advances in equine reproduction, many stages of embryonic and fetal morphological development are poorly understood, with no apparent single source of comprehensive information. Hence, the objective of the present study was to provide a complete macroscopic and microscopic description of the equine embryo/fetus at various gestational ages. Thirty-four embryos/fetuses were aged based on their crown rump length (CRL), and submitted to macroscopic description, biometry, light and scanning microscopy, as well as the alizarin technique. All observed developmental changes were chronologically ordered and described. As examples of the main observed features, an accentuated cervical curvature was observed upon macroscopic examination in all specimens. In the nervous system, the encephalic fourth ventricle and the encephalic vesicles forebrain, midbrain, and hindbrain, were visualized from Day 19 (ovulation = Day 0). The thoracic and pelvic limbs were also visualized; their extremities gave rise to the hoof during development from Day 27. Development of other structures such as pigmented optical vesicle, liver, tail, cardiac area, lungs, and dermal vascularization started on Days 25, 25, 19, 19, 34, and 35, respectively. Light and scanning microscopy facilitated detailed examinations of several organs, e.g., heart, kidneys, lungs, and intestine, whereas the alizarin technique enabled visualization of ossification. Observations in this study contributed to the knowledge regarding equine embryogenesis, and included much detailed data from many specimens collected over a long developmental interval. (C) 2011 Elsevier Inc. All rights reserved.

Lipid structural information from a single equine embryo by MALDI-MS

O objetivo deste trabalho foi relatar o potencial da técnica de MALDI-MS para caracterizar espécies de lipídios presentes em um único embrião equino e estudar algumas estruturas lipídicas detectadas por dissociação induzida por colisão (CID). No espectro de modo íon positivo, pudemos observar espécies, principalmente, protonadas e sodiadas de esfingomielinas (SM), fosfatidileolinas (PC) e triacilgliceróis (TAG). No modo negativo, observamos fosfatidiletanolaminas (PE) e fosfatidilinositos (PI). Espectros de íons de lípidos com maior intensidade foram utilizados para demonstrar o potencial da informação estrutural por MALDI-MS/MS. O espectro no modo positivo de m/z (massa sobre carga) 760,6 (atribuída como PC34:1) apresentou características de fragmentos PC de m/z 184,1 (denominada cabeça polar de colina), além de perda neutral (NL) de m/z 183 (fosforilcolina). Para o íon de m/z 766,6 (atribuída como PE38:5), observou-se a NL de 140, característica do PE. Para o íon de m/z 808,7 (38,5 atribuído como PC), além do fragmento m/z 184,1 na NL de 183, foi possível observar a perda de trimetilamina (íon de m/z 749,6) e o ciclofosfano (íon de m/z 147,0). Finalmente, para o modo de íon negativo, foram isolados e fragmentados o íon de m/z 863,6 que foi atribuído como PI36:1, devido à presença de m/z 153 (fosfato de glicerol – H2O-H ), 223 (inositol fosfo - 2H2O-H) , 241 (fosfoinositol – H2O-H), 281 (ácido oleico) e 581,3 (lisofosfoinositol – H2O+H). Concluímos que a MALDI - MS permite a detecção de uma ampla gama de espécies de PC, SM, PE, PI e TAG lipídicas, bem como a caracterização rápida e confiante de estruturas lipídicas a partir de um único embrião equino.

Effect of eFSH on ovarian cyclicity and embryo production of mares in spring transitional phase

The use of equine FSH (eFSH) for inducing follicular development and ovulation in transitional mares was evaluated. Twenty-seven mares, from 3 to 15 years of age, were examined during the months of August and September 2004, in Brazil. Ultrasound evaluations were performed during 2 weeks before the start of the experiment to confirm transitional characteristics (no follicles larger than 25 mm and no corpus luteum [CL] present). After this period, as the mares obtained a follicle of at least 25 mm, they were assigned to one of two groups: (1) control group, untreated; (2) treated with 12.5 mg eFSH, 2 times per day, until at least half of all follicles larger than 30 mm had reached 35 mm. Follicular activity of all mares was monitored. When most of the follicles from treated mares and a single follicle from control mares acquired a preovulatory size ( : 35 mm), 2,500 IU human chorionic gonadotropin (hCG) was administered IV to induce ovulation. After hCG administration, the mares were inseminated with fresh semen every other day until ovulation. Ultrasound examinations continued until detection of the last ovulation, and embryo recovery was performed 7 to 8 days after ovulation. The mares of the treated group reached the first preovulatoiy follicle (4.1 +/- 1.0 vs 14.9 +/- 10.8 days) and ovulated before untreated mares (6.6 +/- 1.2 vs 18.0 +/- 11.1 days; P <.05). All mares were treated with prostaglandin F-2 alpha (PGF(2 alpha)), on the day of embryo flushing. Three superovulated mares did not cycle immediately after PGF(2 alpha), treatment, and consequently had a longer interovulatory interval (22.4 vs 10.9 days, P < 0.05). The mean period of treatment was 4.79 1.07 days and 85.71% of mares had multiple ovulations. The number of ovulations (5.6 vs 1.0) and embryos (2.0 vs 0.7) per mare were higher (P < 0.05) for treated mares than control mares. In conclusion, treatment with eFSH was effective in hastening the onset of the breeding season, inducing multiple ovulations, and increasing embryo production in transitional mares. This is the first report showing the use of FSH treatment to recover embryos from the first cycle of the year.

Use of a Low Dose of Equine Purified FSH to Induce Multiple Ovulations in Mares

The effects of a low dose of equine purified FSH (eFSH) on incidence of multiple ovulations and embryo recovery rate in mares were studied. During the physiological breeding season in Brazil (19 degrees 45'45'S), 14 Mangalarga Marchador donor mares were used in a crossover study and another 25 mares of the same breed, between 3 years and 12 years of age were used as recipients for the embryo transfers. Donors were monitored during two consecutive oestrus cycles, an untreated control cycle followed by a treated cycle, when eFSH was administered. In both cycles, after an embryo collection attempt on day 8 post-ovulation all mares received 7.5 mg dinoprost and had their two largest follicles tracked daily by ultrasonography until the period of ovulation. Mares were inseminated every 48 h with extended fresh semen from a single stallion after the identification of a 35-mm follicle until the period of ovulation. Ovulations were induced by intravenous administration of 2.500 IU of human chorionic gonadotropin, upon detection of a 35- to 40-mm follicle. In the treated cycle, 5 mg eFSH was given intramuscularly once a day, from day 8 post previous ovulation until at least one follicle reached 35 mm in diameter. Embryo flushes were performed on day 8 of dioestrus (day 0 = ovulation). Treatment with eFSH resulted in higher (p < 0.05) ovulation rate and incidence of multiple ovulations compared to the control (1.6 vs 1.0 and 50% vs 0%, respectively - one mare had triple ovulation). However, embryo recovery rates in the control and treated cycles were similar (0.8 and 1.0, respectively; p > 0.05). Pregnancy rates in the recipient mares following embryo transfer were similar for the control and eFSH cycles (11/11 and 10/14, respectively). Additional studies are necessary in order to develop a low-dose protocol for the use of eFSH that brings a more consistent contribution to the efficiency of commercial equine embryo transfer programs.

Superovulation in mares: Limitations and perspectives

Superovulation is an important tool for routine use in equine embryo transfer (ET) in order to reduce the costs and to enhance the efficiency of ET programs. Satisfactory superovulatory answers (2-7 ovulations) have been reported in mares treated with Equine Pituitary Extract (EPE) and more recently using a commercial Equine FSH. However, embryo recovery rates have been inconsistent and below expectations (20-50% embryos/ovulation). Recent studies have shown that superovulatory treatment leads to disturbances in oocyte maturation and transport, especially in mares with a high ovarian response. Higher and more consistent embryo recovery rates per ovulation have been observed in mares treated with lower doses of EPE. This paper presents a review of recent studies related to superovulation in mares.

Indução de múltiplas ovulações em éguas utilizando baixas doses de acetato de deslorelina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito das características uterinas e dia do ciclo na taxa de prenhez e níveis séricos de progesterona em éguas candidatas à receptora de embrião

Pós-graduação em Medicina Veterinária - FMVZ

Utiização de altrenogest injetável par o estabelecimento e manutençao da gestação em éguas receptoras de embriões acíclicas

Pós-graduação em Medicina Veterinária - FMVZ

Ovarian superstimulatory response and embryo production in mares treated with equine pituitary extract twice daily

Equine pituitary extract (EPE), has been reported to induce multiple ovulation in mares, however ovulation rates are poor in comparison to those obtained in other species. Attempts to improve the effectiveness of EPE for induction of superovulation in cyclic mares has focused on daily frequency of EPE treatment. Two experiments were performed to compare the ovarian response of cyclic mares given EPE once or twice-daily. Mares were assigned to one of two treatment groups 6 to 8 days after ovulation: prostaglandin was given once and EPE (25 mg) was given once daily (Group 1) or twice daily (Group 2). In Experiment 1, more (P < 0.05) follicles 35 mm were detected in mares treated with EPE twice daily (6.1 +/- 3.1) than in mares treated once a daily (2.0 +/- 0.6). In a second experiment, the embryo recovery rates of mares given the two EPE protocols used in Experiment 1 were compared. The number of ovulations per mare was higher (P < 0.05) for mares treated twice-daily (7.1 +/- 5.1, range 3 to 18) than for mares treated once daily (2.4 +/- 1.8, range 1 to 6). The number of embryos produced per mare was higher (P < 0.05) in mares in Group 2 (3.5) than in Group 1 (1.6).Although it is not clear whether the increased ovulation rate is due specifically to dose or frequency, twice-daily administration of a high dose of EPE significantly improved follicular development, ovulation and embryo recovery over the standard treatment of once-daily injection. (C) 2001 by Elsevier B.V.

Improvement of embryo production by the replacement of the last two doses of porcine follicle-stimulating hormone with equine chorionic gonadotropin in Sindhi donors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)