Milagros C Esteso

Milagros C Esteso
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria | INIA · Department of Animal Reproduction

DVM, PhD

About

122
Publications
19,131
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2,438
Citations
Citations since 2017
24 Research Items
1154 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Additional affiliations
January 2009 - present
January 2008 - present
Universidad de Castilla-La Mancha

Publications

Publications (122)
Article
Full-text available
Introduction and objective Cryopreservation of testicular tissues offers new possibilities to protect endangered species, genetically valuable individuals or even the fertility potential of prepubertal individuals who have died unexpectedly. However, the use of this technique still remains a challenge. In this study, slow freezing and vitrification...
Article
Sperm cryopreservation is the most common procedure used to establish germplasm banks for endangered species - but sometimes sperm cells cannot be obtained. In such cases, freezing testicular tissue may be the only option. The testes contains germ cells at different stages of differentiation, including spermatogonia, primary spermatocytes, secondar...
Article
Full-text available
The roe deer is a monoestrous species with a very short rutting season. The present work reports the most suitable period for collecting epididymal sperm and describes the effect of two cooling rates on the post-thaw quality of sperm. Testes were collected 24–48 h after death. Samples of sperm flushed from the epididymis were subjected to either (1...
Poster
Full-text available
INTRODUCCIÓN Uno de los factores que determinará el éxito de la inseminación artificial, como herramienta para difundir comportamientos que favorezcan la actividad cinegética y la conservación de la perdiz roja, es la preservación del semen por refrigeración o congelación. Durante los procesos de almacenamiento espermático se produce un incremento...
Poster
Full-text available
Mito TrackerTM Green [MITO] is a probe capable to stain the mitochondrial membrane of different species; however, we have observed its ability to stain the acrosomal membrane of rooster sperm. The association of MITO and propidium iodide [PI] was used to simultaneously assay the mitochondrial, acrosomal and plasma membranes, of rooster sperm. MITO-...
Poster
Full-text available
It is well known that when a hen mates with multiple roosters, ¡t ¡s the sperm of the last male that usually fertilizes most of the eggs ('last male precedence'). Sperm quality varies between males within a breed, but also between breeds, and thus, sperm competitiveness after mating may depend on the breeds of the roosters involved. The aim of the...
Article
This study compares the effectiveness of the ultra-rapid and conventional freezing of sperm from captive bovids, giraffids, cervids, ursids, a cercopithecid, a delphinid and a phascolarctid. The relationship between sperm head dimensions and cryosurvival was also examined. Compared to conventional freezing, the ultra-rapid freezing of epididymal sp...
Article
Full-text available
Seminal plasma is a key biological fluid that modulates sperm function in the reproduction process. However, its role in sperm biotechnologies is scarce in poultry. The aims of the present study were to study the amino acids profile and total proteins of seminal plasma in 12 Spanish chicken breeds and to investigate the role of seminal plasma on cr...
Data
Protein concentrations in seminal plasma of 12 Spanish rooster breeds. (PDF)
Data
Motility variables of sperm of 12 Spanish rooster breeds (fresh, frozen with plasma and frozen without plasma). (PDF)
Data
Viability and concentration of fresh sperm. Sperm viability of frozen sperm with plasma and without plasma of 12 Spanish rooster breeds. (PDF)
Data
Amino acids profile in seminal plasma of 12 Spanish rooster breeds. (PDF)
Data
Tunel + of sperm of 12 Spanish rooster breeds (fresh, frozen without plasma and frozen with plasma). (PDF)
Article
In this study, there was an examination of the effect on the characteristics of cryopreserved black-footed (Spheniscus demersus) and gentoo (Pygoscelis papua) penguin semen, of thawing at 37 and 5 °C. For two consecutive years, semen was collected and frozen during the April-June period from six gentoo penguins, and during the October-November peri...
Poster
Full-text available
Birchen Leonesa and Blue Leonesa chicken breeds are highly esteemed for their unique feather, ideal for making flies for trout fishing; unfortunately, both breeds are among the endangered Spanish breeds. Ex-situ cryopreservation of sperm cells in gene-banks is an alternative for conservation of these breeds. However, besides the breed, multiple fac...
Article
Full-text available
Sperm cryopreservation protocols are not well defined in many wild species such as the mouflon. The aim was to study the effect of different concentrations of EY on mouflon epididymal sperm cryosurvival. Samples were collected by the flushing method and cryopreserved by the conventional freezing technique in straws using a TEST (TES, Tris, glucose)...
Article
Full-text available
This study examines the effectiveness of two methods for cryopreserving post-mortem epididymal sperm - conventional slow freezing employing a short equilibration time with glycerol, and ultra-rapid freezing - from the wild ruminant species Ovis musimon (mouflon) and Dama dama (fallow deer). A Tris-citric acid-glucose (TCG) + 12% egg yolk-based medi...
Article
The rate at which lethal intracellular ice forms during sperm cryopreservation is highly dependent on the cooling protocol. The present work compares two cooling protocols for use with Iberian ibex (Capra pyrenaica) sperm by assessing the effects on the motility, viability, and size of frozen-thawed sperm cells. Ejaculates, obtained from six adult...
Article
In this study, we successfully described for the first time a vitrification of epididymal Iberian ibex spermatozoa. Spermatozoa from epididymis were obtained from 15 Iberian ibex. The right epididymis' semen sample was vitrified and the left one was frozen. After thawing/warming, samples were selected by density gradient. Sperm characteristics from...
Article
Full-text available
The fertilizing capacity of pure, fresh avian semen may disappear in just half an hour, hindering its successful use in artificial insemination (AI) projects. Longer storage requires the use of infra-physiological temperatures and of semen diluents that help preserve the spermatozoa but that do not interfere with their fertilizing capacity. This st...
Article
Sperm morphometry is one characteristic which may be useful in prediction of fertility and sperm freezability in a species. Knowledge of the sperm characteristics of the ejaculate and the morphometric descriptors is necessary to effectively develop sperm cryopreservation. The aim of the current study was to provide a general description of the sper...
Article
Seminal plasma removal is routine in goat sperm cryopreservation protocols. The classical washing procedure designed to accomplish this usually leaves the pellet resulting from use of this procedure contaminated with dead sperm, debris, and cells other than sperm. This contamination negatively affects viability of sperm after cryopreservation. The...
Article
Full-text available
Postcopulatory sexual selection through sperm competition may be an important evolutionary force affecting many reproductive traits, including sperm morphometrics. Environmental factors such as pollutants, pesticides, and climate change may affect different sperm traits, and thus reproduction, in sensitive bird species. Many sperm-handling processe...
Article
The present study reports the effect of shortening the prefreezing equilibration time with glycerol on the quality of frozen-thawed ejaculated sperm from four Mediterranean mountain ungulates: Cantabrian chamois (_Rupicapra pyrenaica_), Iberian ibex (_Capra pyrenaica_), mouflon (_Ovis musimon_) and aoudad (_Ammotragus lervia_). Ejaculated sperm fro...
Article
This work examines the effectiveness of a TCG (Tris, citric acid, glucose, 6% egg yolk and 5% glycerol) and a TEST (TES, Tris, glucose, 6% egg yolk and 5% glycerol) sperm extender in the freezing of mouflon spermatozoa at slow cooling rates, using different pre-freezing equilibration times (2-3 hr). It also examines the tolerance of mouflon spermat...
Article
Full-text available
Many post-mortem sperm collection techniques have been described for mammalian species, but their use in birds is scarce. This paper compares the efficacy of two post-mortem sperm retrieval techniques - the flushing and float-out methods - in the collection of rooster sperm, in conjunction with the use of two extenders, i.e., L&R-84 medium and Lake...
Article
This paper reports the first successful artificial insemination (AI) of red-legged partridges (Alectoris rufa), the fertility rate achieved, and the length of time sperm cells can survive inside the oviduct (i.e., the post-AI fertile period). Semen from 20 mature males was collected by massage and pooled for use in single intravaginal inseminations...
Article
Full-text available
This paper reports the first successful artificial insemination (AI) of red-legged partridges (Alectoris rufa), the fertility rate achieved, and the length of time sperm cells can survive inside the oviduct (i.e., the post-AI fertile period). Semen from 20 mature males was collected by massage and pooled for use in single intravaginal inseminations...
Article
The use of condoms could provide a means of collecting high-quality spermatozoa from different species under physiological ejaculation conditions. However, certain condom materials may affect sperm functionality. This study examined the spermiotoxicity of different commercial condom materials towards ram and goat spermatozoa. Sperm samples were dil...
Conference Paper
Full-text available
Vitrification, a process in which living cells undergo glasslike solidification, is a relatively new cryopreservation method that can successfully preserve the embryos, oocytes, and even the sperm of certain species. For sperm, at least in the species studied so far, kinetic vitrification would appear to be a better alternative. The simplicity of t...
Conference Paper
Vitrification, a process in which living cells undergo glasslike solidification, is a relatively new cryopreservation method that can successfully preserve the embryos, oocytes, and even the sperm of certain species. For sperm, at least in the species studied so far, kinetic vitrification would appear to be a better alternative. The simplicity of t...
Conference Paper
Full-text available
The aim of this study was to evaluate the fertilizing ability of vitrified and frozen Iberian ibex sperm by assessing heterologous IVF using bovine oocytes. Testes were obtained from mature ibexes that were legally hunted in the Tejeda and Almijara Game Reserve, in southern Spain. Epididymal spermatozoa were collected by the retrograde flushing met...
Article
This work examines the effects of subsequent cycles of freezing-thawing on giant panda (Ailuropoda melanoleuca) sperm morphometry and function, and assesses whether density-gradient centrifugation (DGC) can increase the number of freezing-thawing cycles this sperm can withstand. A sperm sample was collected by electroejaculation from a mature giant...
Article
Computer-assisted systems for the assessment of sperm morphometry (ASMA systems) have been used successfully with several mammalian species. Unfortunately, they have so far been of little use for assessing bird semen, a consequence of the filiform shape of avian spermatozoa. This study compares two staining techniques (Hemacolor(®) and aniline blue...
Article
The objective was to characterize the stress response and the seminal parameters obtained with electroejaculation (EE) or transrectal ultrasound-guided massage of the accessory sex glands (TUMASG) in two captive but nondomestic ruminants, the mouflons and the Iberian ibex under general anesthesia. In mouflons, the physiological responses (heart and...
Article
This paper describes the sperm characteristics and response to cooling and freezing of naturally ejaculated semen from a captive, adult golden eagle (Aquila chrysaetus) trained to allow sperm recovery via cooperative copulation. A basic spermiogram was prepared, and sperm motility and morphometric variables recorded using a computer-aided system. F...
Technical Report
Full-text available
Abstract This paper reports the first successful artificial insemination (AI) of red-legged partridges (Alectoris rufa), the fertility rate achieved, and the length of time sperm cells can survive inside the oviduct (i.e., the post-AI fertile period). Semen from 20 mature males was collected by massage and pooled for use in single intravaginal ins...
Conference Paper
Full-text available
INTRODUCCIÓN La cría de la perdiz roja en granjas ha tenido un fuerte desarrollo para dar respuesta a la gran demanda cinegética de esta especie. El aumento de la cría y suelta de perdices (de 3 a 4 millones de perdices/año; Sánchez et al., 2009) ha consolidado una producción cinegética cada vez más industrializada (González-Redondo et al., 2010)....
Article
Full-text available
The general decline in wild Iberian populations of the red-legged partridge (Alectoris rufa) has been accompanied by an increase in game-farm facilities producing hybrids with chukar partridges (Alectoris chukar). Genetic introgression from chukar partridges is thought to modify male red-legged partridge reproductive indicators. The aim of the pres...
Article
This work examines the effect of the interaction between different concentrations of two cryoprotectants - glycerol (GLY) and dimethylacetamide (DMA) - and two methods of cryopreservation - pellets produced by plunging into liquid nitrogen and gradual in-straw freezing - on frozen/thawed chicken sperm variables. Sperm was cryopreserved using: (i) 6...
Article
Two experiments were conducted to study the effect of shortening the equilibration time with the cryoprotectant glycerol before freezing epididymal sperm recovered post mortem from Iberian ibex. In the first experiment, the standard equilibration time of 3 h was compared to 2 h and subjective sperm motility and quality of movement were greater (P<0...
Article
Contents It is well known that when a hen mates with multiple roosters, it is the sperm of the last male that usually fertilizes most of the eggs ('last male precedence'). Sperm quality varies between males within a breed, but also between breeds, and thus, sperm competitiveness after mating may depend on the breeds of the roosters involved. The ai...
Article
It is well known that when a hen mates with multiple roosters, it is the sperm of the last male that usually fertilizes most of the eggs ('last male precedence'). Sperm quality varies between males within a breed, but also between breeds, and thus, sperm competitiveness after mating may depend on the breeds of the roosters involved. The aim of the...
Article
This study examines whether photoperiod and/or melatonin treatments can improve sperm variables outside the breeding season in the Iberian ibex-a model species for wild mountain ruminants-thus helping in the collection of high quality sperm beyond the normal breeding season for depositing in genetic resource banks. Adult Iberian ibex males (n=17) w...
Article
Full-text available
Background Sperm cryopreservation has become an indispensable tool in biology. Initially, studies were aimed towards the development of efficient freezing protocols in different species that would allow for an efficient storage of semen samples for long periods of time, ensuring its viability. Nowadays, it is widely known that an important individu...
Data
Patterns of response to cryopreservation II. Relationship between sperm head area and p2a relationship for the 38 males used in this study throughout the cryopreservation process: fresh semen (red points), pre-freezing (yellow points) and post-thawing (blue points). Numbers within a circle in the lower-right corner of graphs indicate to which patte...
Data
Patterns of response to cryopreservation I. Relationship between sperm head area and length for the 38 males used in this study throughout the cryopreservation process: fresh semen (red points), pre-freezing (yellow points) and post-thawing (blue points). Numbers within a circle in the lower-right corner of graphs indicate to which pattern each mal...
Article
The aim of this work was to study the effect of storage temperature during the transport of ovaries on cleavage and blastocyst rates in Iberian red deer, because wild populations of this subspecies are usually far from laboratories. A total of 472 ovaries from 236 Iberian hinds were recovered and maintained in saline solution at 5-8 °C or 20-25 °C...
Article
The soybean lecithin is used as a phospholipids source for the commercial extenders available for freezing bull semen which allows replacing the traditional membrane protective of animal origin (egg yolk). These extenders have been tested for freezing semen in various livestock species but specific adjustments cannot be made due to trade protection...
Article
Full-text available
Sperm morphology has been identified as a characteristic that can be useful in the prediction of fertilizing capacity. The aim of the current study was to characterize ram sperm heads morphometrically as a basis for future studies on the relationship between sperm quality and male fertility. For this purpose, ejaculates from 241 mature rams (Ovis a...
Article
Full-text available
The aim of this study was to assess two models of sperm collection on the quality and fertility of thawed spermatozoa from Black Manchega rams, a threatened breed. Sperm samples were collected by electroejaculation and postmortem from each male. Samples were diluted with Biladyl and frozen. Motility (subjective and objective by means of computer-as...
Article
Full-text available
Assisted Sperm Morphometry Analysis (ASMA) was used to de- termine the sperm head dimensions (DCE) of boar by age, and then the data set clustered in sperm subpopulations (SP). To this purpose were evaluated 36 fresh and diluted semen sam- ples of 20 Dalland domestic pigs, which were classified in 2 categories: under 18 months old and over 18 month...
Article
Full-text available
Assisted Sperm Morphometry Analysis (ASMA) was used to determine the sperm head dimensions (DCE) of boar by age, and then the data set clustered in sperm subpopulations (SP). To this purpose were evaluated 36 fresh and diluted semen samples of 20 Dalland domestic pigs, which were classified in 2 categories: under 18 months old and over 18 months ol...
Article
To try new acrosomal probes for assessing ram spermatozoa, we compared the LysoSensor probe, which labels acidic organelles, with the frequently used peanut agglutinin acrosomal probe (PNA-PE; phycoerythrin as fluorescent moiety). The previous microscopic observations showed a lack of relationship of LysoSensor with acrosomal status. Semen was obta...
Conference Paper
This study is an attempt to increase our knowledge on the effect that sperm preparation techniques have on thawed spermatozoa from wild ruminants. Semen banks for wild species can be maintained and used for artificial insemination and IVF, but it is necessary to optimize spermwork. Our objective was to assess the effect of centrifugation, dilution...
Article
Full-text available
The sperm quality and several parameters associated with oxidative stress were evaluated in ram (Ovis aries) spermatozoa suspensions incubated with 0, 50 or 500 ng/mL Pb during 0, 1, 3 or 6 h. The presence of Pb during incubation, reduced the integrity of the acrosome, % sperm motility and integrity, and the functionality of membrane. On the contra...
Article
Full-text available
Fe(2)(+)/ascorbate, hydrogen peroxide (H(2)O(2)), and hypoxanthine/xanthine oxidase (XOD) are commonly used for inducing oxidative stress on spermatozoa. A comparative study of these agents was carried out on thawed spermatozoa from red deer. First, we tested a high, medium, and low concentration of each agent: 100, 10, and 1 microM Fe(2)(+) (hydro...
Article
Full-text available
The assessment of sperm chromatin status is compulsory in a complete spermiogram. Here we applied the sperm chromatin structure assay (SCSA) and the sperm chromatin dispersion (SCD) test to assess the chromatin status of three fighting bulls. Cryopreserved semen (two straws/bull) were analysed by duplicate after thawing and after 6 h at 37 degrees...
Article
Full-text available
We have approached the problem of refrigerated storage of epididymal sperm samples from red deer by comparing three options: storing the genital (testicles within the scrotum), diluting the semen in extender or diluting the semen in extender supplemented with an anti-oxidant. Twenty-nine pairs of testes were collected. Spermatozoa from one of each...
Article
A heterologous in vitro fertilization (IVF) test using calf oocytes with zona pellucida was employed to assess the fertility of thawed ram sperm samples. Six males with significant differences in fertility (P=0.003) were used. The males were classified as having high fertility (>or=42%) and low fertility (<or=41%). Male fertility was not influenced...
Article
Computer-assisted sperm morphometry analysis (CASMA) was used in this study to identify sperm morphometric subpopulations in Iberian red deer epididymal sperm samples. Epididymal sperm samples were collected from 37 mature stags and were divided. One portion was diluted in a Tris-citrate-egg yolk medium. A microscope slide was prepared from single...